American Society of Mechanical Engineers 2015-2017 Code Editions Incorporation by Reference, 26540-26581 [2020-08855]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 85, Number 86 (Monday, May 4, 2020)]
[Rules and Regulations]
[Pages 26540-26581]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-08855]



[[Page 26539]]

Vol. 85

Monday,

No. 86

May 4, 2020

Part II





Nuclear Regulatory Commission





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10 CFR Part 50





American Society of Mechanical Engineers 2015-2017 Code Editions 
Incorporation by Reference; Final Rule

Federal Register / Vol. 85, No. 86 / Monday, May 4, 2020 / Rules and 
Regulations

[[Page 26540]]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2016-0082]
RIN 3150-AJ74


American Society of Mechanical Engineers 2015-2017 Code Editions 
Incorporation by Reference

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its 
regulations to incorporate by reference the 2015 and 2017 Editions of 
the American Society of Mechanical Engineers Boiler and Pressure Vessel 
Code and the 2015 and 2017 Editions of the American Society of 
Mechanical Engineers Operation and Maintenance of Nuclear Power Plants, 
Division 1: OM Code: Section IST, for nuclear power plants. The NRC is 
also incorporating by reference two revised American Society of 
Mechanical Engineers code cases. This action is in accordance with the 
NRC's policy to periodically update the regulations to incorporate by 
reference new editions of the American Society of Mechanical Engineers 
Codes and is intended to maintain the safety of nuclear power plants 
and to make NRC activities more effective and efficient.

DATES: This final rule is effective on June 3, 2020. The incorporation 
by reference of certain publications listed in the regulation is 
approved by the Director of the Federal Register as of June 3, 2020.

ADDRESSES: Please refer to Docket ID NRC-2016-0082 when contacting the 
NRC about the availability of information for this action. You may 
obtain publicly-available information related to this action by any of 
the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2016-0082. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions contact 
the individuals listed in the FOR FURTHER INFORMATION CONTACT section 
of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``ADAMS Public Documents'' and 
then select ``Begin Web-based ADAMS Search.'' For problems with ADAMS, 
please contact the NRC's Public Document Room (PDR) reference staff at 
1-800-397-4209, 301-415-4737, or by email to [email protected]. For 
the convenience of the reader, instructions about obtaining materials 
referenced in this document are provided in the ``Availability of 
Documents'' section.
     Attention: The Public Document Room (PDR), where you may 
examine and order copies of public documents is currently closed. You 
may submit your request to the PDR via email at [email protected] or 
call 1-800-397-4209 between 8:00 a.m. and 4:00 p.m. (EST), Monday 
through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: James G. O'Driscoll, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1325, email: 
James.O'[email protected]; or Keith Hoffman, Office of Nuclear Reactor 
Regulation, telephone: 301-415-1294, email: [email protected]. Both 
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.

SUPPLEMENTARY INFORMATION:

Executive Summary

A. Need for the Regulatory Action

    The NRC is amending its regulations to incorporate by reference the 
2015 and 2017 Editions of the American Society of Mechanical Engineers 
(ASME) Boiler and Pressure Vessel Code (BPV Code) and the 2015 and 2017 
Editions of the ASME Operation and Maintenance of Nuclear Power Plants, 
Division 1: OM Code: Section IST (OM Code), for nuclear power plants. 
The NRC is also incorporating by reference two ASME code cases.
    The ASME periodically revises and updates its codes for nuclear 
power plants by issuing new editions; this final rule is in accordance 
with the NRC's practice to incorporate those new editions into the 
NRC's regulations. This rule maintains the safety of nuclear power 
plants, makes NRC activities more effective and efficient, and allows 
nuclear power plant licensees and applicants to take advantage of the 
latest ASME Codes. The ASME is a voluntary consensus standards 
organization, and the ASME Codes are voluntary consensus standards. The 
NRC's use of the ASME Codes is consistent with applicable requirements 
of the National Technology Transfer and Advancement Act (NTTAA). See 
also Section XIV of this document, ``Voluntary Consensus Standards.''

B. Major Provisions

    Major provisions of this final rule include:
     Incorporation by reference of ASME Codes (2015 and 2017 
Editions of the BPV Code and the OM Code) into NRC regulations and 
delineation of NRC requirements for the use of these codes, including 
conditions.
     Incorporation by reference of two revised ASME Code Cases 
and delineation of NRC requirements for the use of these code cases, 
including conditions.
     Incorporation by reference of Electric Power Research 
Institute (EPRI), Topical Report, ``Materials Reliability Program: 
Topical Report for Primary Water Stress Corrosion Cracking Mitigation 
by Surface Stress Improvement'' (MRP-335, Revision 3-A), which provides 
requirements for the mitigation of primary water stress corrosion 
cracking on reactor vessel head penetrations and dissimilar metal butt 
welds.

C. Costs and Benefits

    The NRC prepared a regulatory analysis to determine the expected 
costs and benefits of this final rule. The regulatory analysis 
identifies costs and benefits in both a quantitative fashion as well as 
in a qualitative fashion.
    Based on the analysis, the NRC concludes that this final rule 
results in a net quantitative averted cost to the industry and the NRC. 
This final rule, relative to the regulatory baseline, results in a net 
averted cost for industry of $3.06 million based on a 7 percent net 
present value (NPV) and $3.29 million based on a 3 percent NPV. The 
estimated incremental industry averted cost per reactor unit ranges 
from $34,000 based on a 7 percent NPV to $36,600 based on a 3 percent 
NPV. The rulemaking alternative benefits the NRC by averting costs for 
reviewing and approving requests to use alternatives to the codes on a 
plant-specific basis under Sec.  50.55a(z) of title 10 of the Code of 
Federal Regulations (10 CFR). The NRC net benefit ranges from $3.17 
million (based on a 7 percent NPV) to $3.61 million (based on a 3 
percent NPV).
    Qualitative factors that were considered include regulatory 
stability and predictability, regulatory efficiency, and consistency 
with the provisions of the NTTAA. The regulatory analysis includes a 
discussion of the costs and benefits that were considered 
qualitatively. If the results of the regulatory analysis were based 
solely on quantified costs and benefits, the regulatory analysis would 
show that the rulemaking is justified because the total

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quantified benefits of the regulatory action equal or exceed the costs 
of the action. When the qualitative benefits (including the safety 
benefit, cost savings, and other non-quantified benefits) are 
considered together with the quantified benefits, the benefits outweigh 
the identified quantitative and qualitative impacts.
    The NRC has a decades-long practice of approving and/or mandating 
the use of certain parts of editions and addenda of the ASME Codes in 
Sec.  50.55a. Continuing this practice in this final rule ensures 
regulatory stability and predictability. The practice also provides 
consistency across the industry and assures the industry and the public 
that the NRC will continue to support the use of the most updated and 
technically sound techniques developed by the ASME to provide adequate 
protection to the public. In this regard, the ASME Codes are voluntary 
consensus standards developed by technical committees composed of 
mechanical engineers and others who represent the broad and varied 
interests of their industries, from manufacturers and installers to 
insurers, inspectors, distributors, regulatory agencies, and end users. 
The standards have undergone extensive external review before being 
considered to be incorporated by reference by the NRC. Finally, the 
NRC's use of the ASME Codes is consistent with the NTTAA, which directs 
Federal agencies to adopt voluntary consensus standards instead of 
developing ``government-unique'' (i.e., Federal agency-developed) 
standards, unless inconsistent with applicable law or otherwise 
impractical.
    For more information, please see the regulatory analysis in ADAMS 
under Accession No. ML19098A807.

TABLE OF CONTENTS

I. Background
II. Discussion
    A. ASME BPV Code, Section III
    B. ASME BPV Code, Section XI
    C. ASME OM Code
    D. ASME Code Cases
III. Public Outreach
IV. NRC Responses to Public Comments
V. Section-by-Section Analysis
VI. Generic Aging Lessons Learned Report
VII. Regulatory Flexibility Certification
VIII. Regulatory Analysis
IX. Backfitting and Issue Finality
X. Plain Writing
XI. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XII. Paperwork Reduction Act Statement
XIII. Congressional Review Act
XIV. Voluntary Consensus Standards
XV. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XVI. Availability of Guidance
XVII. Availability of Documents

I. Background

    The American Society of Mechanical Engineers develops and publishes 
the BPV Code, which contains requirements for the design, construction, 
and inservice inspection (ISI) of nuclear power plant components; and 
the ASME Operation and Maintenance of Nuclear Power Plants, Division 1: 
OM Code: Section IST (OM Code),\1\ which contains requirements for 
inservice testing (IST) of nuclear power plant components. Until 2012, 
the ASME issued new editions of the ASME BPV Code every 3 years and 
addenda to the editions annually, except in years when a new edition 
was issued. Similarly, the ASME periodically published new editions and 
addenda of the ASME OM Code. Starting in 2012, the ASME decided to 
issue editions of its BPV and OM Codes (no addenda) every 2 years with 
the BPV Code to be issued on the odd years (e.g., 2013, 2015, etc.) and 
the OM Code to be issued on the even years \2\ (e.g., 2012, 2014, 
etc.). The new editions and addenda typically revise provisions of the 
ASME Codes to broaden their applicability, add specific elements to 
current provisions, delete specific provisions, and/or clarify them to 
narrow the applicability of the provision. The revisions to the 
editions and addenda of the ASME Codes do not significantly change code 
philosophy or approach.
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    \1\ The editions and addenda of the ASME Code for Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
2005 to 2017 and are referred to collectively in this rule as the 
``OM Code.''
    \2\ The 2014 Edition of the ASME OM Code was delayed and was 
designated the 2015 Edition. Similarly, the 2016 Edition of the OM 
Code was delayed and was designated the 2017 Edition.
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    The NRC's practice is to establish requirements for the design, 
construction, operation, ISI (examination), and IST of nuclear power 
plants by approving the use of editions and addenda of the ASME BPV and 
OM Codes (ASME Codes) in Sec.  50.55a of title 10 of the Code of 
Federal Regulations (10 CFR). The NRC approves or mandates the use of 
certain parts of editions and addenda of these ASME Codes in Sec.  
50.55a through the rulemaking process of ``incorporation by 
reference.'' Upon incorporation by reference of the ASME Codes into 
Sec.  50.55a, the provisions of the ASME Codes are legally-binding NRC 
requirements as delineated in Sec.  50.55a, and subject to the 
conditions on certain specific ASME Codes' provisions that are set 
forth in Sec.  50.55a. The editions and addenda of the ASME BPV and OM 
Codes were last incorporated by reference into the NRC's regulations in 
a final rule dated July 18, 2017 (82 FR 32934) and amended January 18, 
2018 (83 FR 2525).
    The ASME Codes are consensus standards developed by participants, 
including the NRC and licensees of nuclear power plants, who have broad 
and varied interests. The ASME's adoption of new editions of, and 
addenda to, the ASME Codes does not mean that there is unanimity on 
every provision in the ASME Codes. There may be disagreement among the 
technical experts, including the NRC's representatives on the ASME Code 
committees and subcommittees, regarding the acceptability or 
desirability of a particular code provision included in an ASME-
approved Code edition or addenda. If the NRC determines that there is a 
significant technical or regulatory concern with a provision in an 
ASME-approved Code edition or addenda being considered for 
incorporation by reference, then the NRC conditions the use of that 
provision when it incorporates by reference that ASME Code edition or 
addenda into its regulations. In some instances, the condition 
increases the level of safety afforded by the ASME Code provision, or 
addresses a regulatory issue not considered by the ASME. In other 
instances, where research data or experience has shown that certain 
code provisions are unnecessarily conservative, the condition may 
provide that the code provision need not be complied with in some or 
all respects. The NRC's conditions are included in Sec.  50.55a, 
typically in paragraph (b) of that section. In a Staff Requirements 
Memorandum dated September 10, 1999, (ADAMS Accession No. ML003755050) 
the Commission indicated that NRC rulemakings adopting (incorporating 
by reference) a voluntary consensus standard must identify and justify 
each part of the standard that is not adopted. For this final rule, the 
provisions of the 2015 and 2017 Editions of Section III, Division 1; 
and the 2015 and 2017 Editions of Section XI, Division 1, of the ASME 
BPV Code; and the 2015 and 2017 Editions of the ASME OM Code that the 
NRC is not adopting, or is only partially adopting, are identified in 
the Discussion, Regulatory Analysis, and Backfitting and Issue Finality 
sections of this document. The provisions of those specific editions 
and code cases that are the subject of this final rule that the NRC 
finds to be conditionally acceptable, together with the applicable

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conditions, are also identified in the Discussion, Regulatory Analysis, 
and Backfitting and Issue Finality sections of this document.
    The ASME Codes are voluntary consensus standards, and the NRC's 
incorporation by reference of these codes is consistent with applicable 
requirements of the NTTAA. Additional discussion on the NRC's 
compliance with the NTTAA is set forth in Section XIV of this document, 
``Voluntary Consensus Standards.''

II. Discussion

    The NRC regulations incorporate by reference ASME Codes for nuclear 
power plants. This final rule is the latest in a series of rulemakings 
to amend the NRC's regulations to incorporate by reference revised and 
updated ASME Codes for nuclear power plants. This final rule is 
intended to maintain the safety of nuclear power plants and make NRC 
activities more effective and efficient.
    The NRC follows a three-step process to determine acceptability of 
new provisions in new editions to the Codes and the need for conditions 
on the uses of these Codes. This process was employed in the review of 
the Codes that are the subjects of this rule. First, the NRC staff 
actively participates with other ASME committee members with full 
involvement in discussions and technical debates in the development of 
new and revised Codes. This includes a technical justification of each 
new or revised Code. Second, the NRC's committee representatives 
discuss the Codes and technical justifications with other cognizant NRC 
staff to ensure an adequate technical review. Third, the NRC position 
on each Code is reviewed and approved by NRC management as part of the 
rule amending Sec.  50.55a to incorporate by reference new editions of 
the ASME Codes and conditions on their use. This regulatory process, 
when considered together with the ASME's own process for developing and 
approving the ASME Codes, provides reasonable assurance that the NRC 
approves for use only those new and revised Code edition and addenda, 
with conditions as necessary, that provide reasonable assurance of 
adequate protection to the public health and safety, and that do not 
have significant adverse impacts on the environment.
    The NRC is amending its regulations to incorporate by reference:
     The 2015 and 2017 Editions to the ASME BPV Code, Section 
III, Division 1 and Section XI, Division 1, with conditions on their 
use.
     The 2015 and 2017 Editions to Division 1 of the ASME OM 
Code, with conditions on their use.
     ASME BPV Code Case N-729-6, ``Alternative Examination 
Requirements for PWR [Pressurized Water Reactor] Reactor Vessel Upper 
Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds, 
Section XI, Division 1,'' ASME approval date: March 3, 2016, with 
conditions on its use.
     ASME BPV Code Case N-770-5, ``Alternative Examination 
Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel 
Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler 
Material With or Without Application of Listed Mitigation Activities, 
Section XI, Division 1,'' ASME approval date: November 7, 2016, with 
conditions on its use.
     ``Materials Reliability Program: Topical Report for 
Primary Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement'' (MRP-335, Revision 3-A), EPRI approval date: November 
2016, with conditions on its use.
    The current regulations in Sec.  50.55a(a)(1)(i) incorporate by 
reference ASME BPV Code, Section III, 1963 Edition through the 1970 
Winter Addenda; and the 1971 Edition (Division 1) through the 2013 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(1)(i) through (b)(1)(ix). This final rule revises Sec.  
50.55a(a)(1)(i) to incorporate by reference the 2015 and 2017 Editions 
(Division 1) of the ASME BPV Code, Section III.
    The current regulations in Sec.  50.55a(a)(1)(ii) incorporate by 
reference ASME BPV Code, Section XI, 1970 Edition through the 1976 
Winter Addenda; and the 1977 Edition (Division 1) through the 2013 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(2)(i) through (b)(2)(xxxvii). This final rule revises 
Sec.  50.55a(a)(1)(ii) to remove exclusions from the incorporation by 
reference of specific paragraphs of the 2011a Addenda and the 2013 
Edition of ASME BPV Code, Section XI, as explained in this final rule. 
This final rule also revises Sec.  50.55a(a)(1)(ii) to incorporate by 
reference 2015 and 2017 Editions (Division 1) of the ASME BPV Code, 
Section XI. It also clarifies the wording and adds, removes, or revises 
some of the conditions as explained in this final rule.
    The current regulations in Sec.  50.55a(a)(1)(iv) incorporate by 
reference ASME OM Code, 1995 Edition through the 2012 Edition, subject 
to the conditions currently identified in Sec.  50.55a(b)(3)(i) through 
(b)(3)(xi). The NRC is revising Sec.  50.55a(a)(1)(iv) to incorporate 
by reference the 2015 and 2017 Editions of Division 1 of the ASME OM 
Code. As a result, the NRC regulations incorporate by reference in 
Sec.  50.55a the 1995 Edition through the 2017 Edition of the ASME OM 
Code.
    The NRC is revising Sec.  50.55a(a)(4) to include the Electric 
Power Research Institute, Materials Reliability Program, 3420 Hillview 
Avenue, Palo Alto, CA 94304-1338; telephone: 1-650-855-200; https://www.epri.com, as a new source for a standard incorporated by reference 
in Sec.  50.55a.
    The NRC reviewed changes to the Codes in the editions of the Codes 
identified in this final rule, and published a proposed rule in the 
Federal Register setting forth the NRC's proposal to incorporate by 
reference the ASME Codes, together with proposed conditions on their 
use (83 FR 56156; November 9, 2018). After consideration of the public 
comments received on the proposed rule (public comments are discussed 
in Section IV of this document, ``NRC Responses to Public Comments''), 
the NRC concludes, in accordance with the process for review of changes 
to the Codes, that each of the editions of the Codes, are technically 
adequate, consistent with current NRC regulations, and approved for use 
with specified conditions set forth in this final rule. Each of the NRC 
conditions and the reasons for each condition are discussed in the 
following sections of this document. The discussions are organized 
under the applicable ASME Code and Section.
    The two ASME Code Cases being incorporated by reference in this 
final rule (N-729-6 and N-770-5) are discussed in Section II.D of this 
document, ``ASME Code Cases.''

A. ASME BPV Code, Section III

10 CFR 50.55a(a)(1)(i)(E) Rules for Construction of Nuclear Facility 
Components--Division 1
    The NRC is revising Sec.  50.55a(a)(1)(i)(E) to incorporate by 
reference the 2015 and 2017 Editions of the ASME BPV Code, Section III, 
including Subsection NCA and Division 1 Subsections NB through NH (for 
the 2015 Edition) and Subsections NB through NG (for the 2017 Edition) 
and Appendices. As stated in Sec.  50.55a(a)(1)(i), the Nonmandatory 
Appendices are excluded and not incorporated by reference. The 
Mandatory Appendices are incorporated by reference because they include 
information necessary for Division 1.

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However, the Mandatory Appendices also include material that pertains 
to other Divisions that have not been reviewed and approved by the NRC. 
Although this information is included in the sections and appendices 
being incorporated by reference, the NRC notes that the use of 
Divisions other than Division 1 has not been approved, nor are these 
Divisions required by NRC regulations and, therefore, such information 
is not relevant to current applicants and licensees. Therefore, this 
rule clarifies that current applicants and licensees may only use the 
sections of the Mandatory Appendices that pertain to Division 1. The 
NRC is not taking a position on the non-Division 1 information in the 
appendices and is including it in the incorporation by reference only 
for convenience.
10 CFR 50.55a(b)(1)(v) Section III Condition: Independence of 
Inspection
    The 1995 Edition through the 2009b Addenda of the 2007 Edition of 
ASME BPV Code, Section III, Subsection NCA, endorsed the NQA-1-1994 
Edition (Nuclear Quality Assurance-1) in NCA-4000, ``Quality 
Assurance.'' Paragraph (a) of NCA-4134.10, ``Inspection,'' states, 
``The provisions of NQA-1 Basic Requirement 10 and Supplement 10S-1, 
shall apply, except for paragraph 3.1, and the requirements of 
Inservice Inspection.'' Paragraph 3.1, ``Reporting Independence,'' of 
Supplement 10S-1, of NQA-1, states, ``Inspection personnel shall not 
report directly to the immediate supervisors who are responsible for 
performing the work being inspected.'' In the 2010 Edition through the 
latest ASME BPV Code Editions of NCA, the Code removed the paragraph 
3.1 exception for reporting independence.
    Based on the above changes to the Code, the NRC is revising the 
condition to limit the condition so that it is applicable only for the 
1995 Edition through 2009b Addenda of the 2007 Edition, where the NQA-
1-1994 Edition is referenced.
    In response to public comments on the proposed revision to this 
condition, the NRC is revising the condition to clarify that that the 
condition applies to only paragraph 3.1 of Supplement 10S-1 of NQA-1-
1994 Edition.
10 CFR 50.55a(b)(1)(vi) Section III Condition: Subsection NH
    The NRC is revising the existing condition since Subsection NH of 
Section III Division 1 no longer exists in the 2017 Edition of ASME BPV 
Code, Section III Division 1. The change is to reflect that Subsection 
NH existed from the 1995 Addenda through 2015 Edition of Section III 
Division 1. In 2015, Subsection NH contents also were included in 
Section III Division 5 Subpart B. In the 2017 Edition of the ASME Code, 
Subsection NH was deleted from Division 1 of Section III and became 
part of Division 5 of Section III. Division 5 of Section III is not 
incorporated by reference in Sec.  50.55a. Therefore, the NRC is 
revising the condition to make it applicable to the 1995 Addenda 
through all Editions and addenda up to and including the 2013 Edition.
10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts
    Visual examination is one of the processes for acceptance of a 
bolt, stud, or nut to ensure its structural integrity and its ability 
to perform its intended function. The 2015 Edition of the ASME Code 
contains this requirement; however, the 2017 Edition does not require 
these visual examinations to be performed in accordance with NX-5100 
and NX-5500. Therefore, the NRC is adding two conditions to ensure 
adequate procedures remain and qualified personnel remain capable of 
determining the structural integrity of these components.
10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts, First Provision
    The NRC is adding Sec.  50.55a(b)(1)(x) to condition the provisions 
of NB-2582, NC-2582, ND-2582, NE-2582, NF-2582, NG-2582 in the 2017 
Edition of Section III. The condition is that visual examinations are 
required to be performed in accordance with procedures qualified to NB-
5100, NC-5100, ND-5100, NE-5100, NF-5100, and NG-5100, and personnel 
qualified to NB-5500, NC-5500, ND-5500, NE-5500, NF-5500, and NG-5500, 
respectively. The 2015 Edition of the ASME Code contains this 
requirement. The visual examination is one of the processes for 
acceptance of the final product to ensure its structural integrity and 
its ability to perform its intended function. The 2017 Edition does not 
require these visual examinations to be performed in accordance with 
NX-5100 and NX-5500. All other final examinations (magnetic particle 
testing (MT), liquid penetrant testing (PT), ultrasonic testing (UT) 
and radiographic testing (RT)) for acceptance of the final product in 
the 2017 Edition require the procedures and personnel to be qualified 
to NX-5100 and NX-5500.
    Therefore, the NRC is adding Sec.  50.55a(b)(1)(x)(A) to condition 
the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-2582,and NG-
2582 in the 2017 Edition of Section III to require that procedures are 
qualified to NB-5100, NC-5100, ND-5100, NE-5100, NF-5100, and NG-5100, 
and personnel are qualified to NB-5500, NC-5500, ND-5500, NE-5500, NF-
5500, and NG-5500, respectively, in order to ensure adequate procedures 
and personnel remain capable of determining the structural integrity of 
these components. This is particularly important for small bolting, 
studs, and nuts that only receive a visual examination. As stated in 
NX-4123 of Section III, only inspections performed in accordance with 
Article NX-4000 (e.g., marking, dimensional measurement, fitting, 
alignment) are exempted from NX-5100 and NX-5500, and may be qualified 
in accordance with the Certificate Holder's Quality Assurance Program.
10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts, Second Provision
    The 2017 Edition requires that the final surfaces of threads, 
shanks, and heads be visually examined for workmanship, finish, and 
appearance in accordance with ASTM F788, for bolting material, and ASTM 
F812, for nuts. This examination is for acceptance of the final product 
to ensure its structural integrity, especially for small bolting that 
only receives a visual examination. However, performing an inspection 
for workmanship or appearance to the bolting specification is not 
necessarily sufficient to ensure the integrity of the bolts and nuts 
for their intended function in a reactor. The visual examination in 
Section III for bolting and nuts is intended to determine structural 
integrity for its intended function, which may entail quality 
requirements more stringent than the bolting specifications. As 
specified in the 2015 Edition of Section III: ``discontinuities such as 
laps, seams, or cracks that would be detrimental to the intended 
service are unacceptable.''
    Therefore, the NRC is adding Sec.  50.55a(b)(1)(x)(B) to condition 
the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-2582, and NG-
2582 in the 2017 Edition of Section III, to require that bolts, studs, 
and nuts must be visually examined for discontinuities including 
cracks, bursts, seams, folds, thread lap, voids and tool marks.
10 CFR 50.55a(b)(1)(xi) Section III Condition: Mandatory Appendix XXVI
    The NRC is adding a new paragraph with conditions on the use of 
ASME BPV Code, Section III, Appendix XXVI, for installation of high 
density

[[Page 26544]]

polyethylene (HDPE) pressure piping. This Appendix is new in the 2015 
Edition of Section III, and electrofusion joining was added to this 
Appendix in the 2017 Edition of Section III. The 2015 Edition of 
Section III is the first time the ASME Code has provided standards for 
the use of polyethylene piping. The NRC has determined that the 
conditions that follow in Sec.  50.55a(b)(1)(xi)(A) through (C) are 
necessary in order to use polyethylene piping in Class 3 safety-related 
applications. The conditions in Sec.  50.55a(b)(1)(xi)(A) and (B) 
pertain to butt fusion joints and apply to both the 2015 and 2017 
Editions of Section III. The conditions in Sec.  50.55a(b)(1)(xi)(C) 
pertain to electrofusion joints and apply only to the 2017 Edition of 
Section III.
    Both NRC and industry-funded independent research programs have 
shown that joint failure is the most likely cause of structural failure 
in HDPE piping systems. Poorly manufactured joints are susceptible to 
early structural failure driven by ``slow crack growth,'' a form of 
subcritical creep crack growth that is active in HDPE. The following 
three provisions are aimed at ensuring the highest quality for joints 
in HDPE systems and reducing the risk of poor joint fabrication. These 
provisions minimize the risk of joint structural failure and the 
resulting potential loss of system safety function.
10 CFR 50.55a(b)(1)(xi)(A) Mandatory Appendix XXVI: First Provision
    The NRC is adding a new paragraph (b)(1)(xi)(A), which specifies 
the essential variables to be used in qualifying fusing procedures for 
butt fusion joints in polyethylene piping installed in accordance with 
ASME Section III, Mandatory Appendix XXVI. The NRC does not endorse the 
use of a standardized fusing procedure specification. A fusion 
procedure specification will need to be generated for each butt fusion 
joint with the essential variables, as listed.
    Per ASME BPV Code Section IX, QF-252, essential variables are those 
that will affect the mechanical properties of the fused joint, if 
changed, and require requalification of the Fusing Procedure 
Specification (FPS), Standard Fusing Procedure Specification (SFPS), or 
Manufacturer Qualified Electrofusion Procedure Specification (MEFPS) 
when any change exceeds the specified limits of the values recorded in 
the FPS for that variable. Fourteen essential variables for HDPE butt 
fusion joints for nuclear applications have been identified by NRC and 
industry experts through extensive research and field experience. Ten 
of these essential variables are the same as those identified in ASME 
BPV Code, Section IX, Table QF-254, which applies to all HDPE butt 
fusions and is not limited to nuclear applications. The other four 
variables deemed essential by the NRC are: Diameter, cross-sectional 
area, ambient temperature, and fusing machine carriage model. These 
four additional variables are recognized by industry experts as being 
essential for butt fusion joints in nuclear safety applications and 
have been included in a proposal to list essential variables for butt 
fusion in the 2019 Edition of ASME BPV Code, Section III, Mandatory 
Appendix XXVI.
    For nuclear applications, the use of HDPE is governed by ASME BPV 
Code, Section III, Mandatory Appendix XXVI. The NRC has determined that 
to ensure butt fusion joint quality is adequate for nuclear safety 
applications, referencing ASME BPV Code, Section IX in ASME BPV Code, 
Section III, Mandatory Appendix XXVI is not sufficient, because ASME 
BPV Code, Section IX is not incorporated into NRC regulations. 
Therefore, the NRC is including the essential variables for HDPE butt 
fusion as a condition on the use of ASME BPV Code Section III, 
Mandatory Appendix XXVI. This provision addresses the fact that the 
essential variables for HDPE butt fusion are not listed in the 2015 and 
2017 Editions of ASME BPV Code, Section III, Mandatory Appendix XXVI. 
Proposals to incorporate these essential variables for butt fusion in 
the 2019 Edition of the Code have already been drafted and circulated 
within the ASME Code Committees. In the meantime, the NRC is adding 
this provision to ensure butt fusion joint quality for nuclear safety 
applications.
10 CFR 50.55a(b)(1)(xi)(B) Mandatory Appendix XXVI: Second Provision
    The NRC is adding a new paragraph (b)(1)(xi)(B), which requires 
bend tests or high speed tensile impact testing to qualify fusing 
procedures for joints in polyethylene piping installed in accordance 
with ASME BPV Code, Section III, Mandatory Appendix XXVI.
    Based on limited confirmatory research on the inservice behavior of 
HDPE butt fusion joints, as well as research results from The Welding 
Institute in the UK, the NRC has determined the need to add a condition 
to ensure the quality of butt fusion joints. When performing procedure 
qualification for high speed tensile impact testing of butt fusion 
joints in accordance with XXVI-2300 or XXVI-4330, breaks in the 
specimen that are away from the fusion zone must be retested. When 
performing fusing operator qualification bend tests of butt fusion 
joints in accordance with XXVI-4342, guided side bend testing must be 
used for all thicknesses greater than 1.25 inches.
10 CFR 50.55a(b)(1)(xi)(C) Mandatory Appendix XXVI: Third Provision
    The NRC is adding a new paragraph (b)(1)(xi)(C), which specifies 
the essential variables to be used in qualifying fusing procedures for 
electrofusion of fusion joints in polyethylene piping that is to be 
installed in accordance with ASME BPV Code, Section III, Mandatory 
Appendix XXVI. The NRC does not endorse the use of a standardized 
fusing procedure specification. A fusion procedure specification will 
need to be generated for each electrofusion joint with the essential 
variables as listed.
    Per ASME BPV Code, Section IX, QF-252: ``Essential variables are 
those that will affect the mechanical properties of the fused joint, if 
changed, and require requalification of the FPS, SFPS, or MEFPS when 
any change exceeds the specified limits of the values recorded in the 
FPS for that variable.'' Sixteen essential variables for HDPE 
electrofusion for nuclear applications have been identified by NRC and 
industry experts through extensive research and field experience. 
Twelve of these essential variables are the same as those identified in 
ASME BPV Code, Section IX Table QF-255, which applies to all HDPE 
electrofusion and is not limited to nuclear applications. The other 
four variables deemed essential by the NRC are: Fitting polyethylene 
material, pipe wall thickness, power supply, and processor. These four 
additional variables are recognized by industry experts as being 
essential for electrofusion joints in nuclear safety applications and 
have been included in a proposal to list essential variables for 
electrofusion in the 2019 Edition of ASME BPV Code, Section III 
Mandatory Appendix XXVI.
    For nuclear applications, the use of HDPE is governed by ASME BPV 
Code, Section III Mandatory Appendix XXVI. The NRC has determined that, 
to ensure electrofusion joint quality is adequate for nuclear safety 
applications, referencing ASME BPV Code, Section IX in ASME BPV Code, 
Section III Mandatory Appendix XXVI is not sufficient, because ASME BPV 
Code, Section IX is not incorporated into NRC regulations. Therefore, 
the NRC is including the essential variables for HDPE electrofusion as 
a condition on the use of ASME Section III, Mandatory Appendix XXVI. 
This provision addresses the fact that the essential

[[Page 26545]]

variables for HDPE electrofusion are not listed in the 2015 and 2017 
Editions of ASME BPV Code, Section III, Mandatory Appendix XXVI. 
Proposals to incorporate these essential variables for electrofusion in 
the 2019 Edition of the Code have already been drafted and circulated 
within the ASME Code Committees. In the meantime, the NRC is adding 
this provision to ensure electrofusion joint quality for nuclear safety 
applications.
10 CFR 50.55a(b)(1)(xii) Section III Condition: Certifying Engineer
    The NRC is adding a new condition Sec.  50.55a(b)(1)(xii) Section 
III Condition: Certifying Engineer. In the 2017 Edition of ASME BPV 
Code, Section III, Subsection NCA, the following Subsections were 
updated to replace the term ``Registered Professional Engineer,'' with 
term ``Certifying Engineer'' to be consistent with ASME BPV Code 
Section III Mandatory Appendix XXIII.

 NCA-3255 ``Certification of the Design Specifications''
 NCA-3360 ``Certification of the Construction Specification, 
Design Drawings, and Design Report''
 NCA-3551.1 ``Design Report''
 NCA-3551.2 ``Load Capacity Data Sheet''
 NCA-3551.3 ``Certifying Design Report Summary'' and
 NCA-3555 ``Certification of Design Report''
 Table NCA-4134.17-2, ``Nonpermanent Quality Assurance 
Records''
 NCA-5125, ``Duties of Authorized Nuclear Inspector 
Supervisors''
 NCA-9200, ``Definitions''

    The NRC reviewed these changes and has determined that the use of a 
Certifying Engineer instead of a Registered Professional Engineer 
applies only to non-U.S. nuclear facilities. The NRC has determined 
that a Certifying Engineer, who is also a Registered Professional 
Engineer licensed in one of the states of the United States, is 
acceptable for U.S. nuclear facilities regulated by the NRC. As a 
result, the NRC is adding a new condition to Sec.  50.55a(b)(1), that 
would not allow applicants and licensees to use a Certifying Engineer 
who is not also a Registered Professional Engineer for code-related 
activities that are applicable to U.S. nuclear facilities regulated by 
the NRC.

B. ASME BPV Code, Section XI

10 CFR 50.55a(b)(2) Conditions on ASME BPV Code, Section XI
    The NRC is amending the regulations in Sec.  50.55a(b)(2) to 
incorporate by reference the 2015 and the 2017 Editions (Division 1) of 
the ASME BPV Code, Section XI. The current regulations in Sec.  
50.55a(b)(2) incorporate by reference ASME BPV Code, Section XI, 1970 
Edition through the 1976 Winter Addenda; and the 1977 Edition (Division 
1) through the 2013 Edition (Division 1), subject to the conditions 
identified in current Sec.  50.55a(b)(2)(i) through (xxix). This final 
rule revises the introductory text to Sec.  50.55a(b)(2) to incorporate 
by reference the 2015 Edition (Division 1) and the 2017 Edition 
(Division 1) of the ASME BPV Code, Section XI, clarifies the wording, 
and revises or provides some additional conditions.
10 CFR 50.55a(b)(2)(vi) Effective Edition and Addenda of Subsection IWE 
and Subsection IWL
    The NRC is removing the existing condition Sec.  50.55a(b)(2)(vi). 
A final rule was published in the Federal Register (61 FR 41303) on 
August 8, 1996, which incorporated by reference the ASME BPV Code, 
Section XI, Subsection IWE and Subsection IWL for the first time. The 
associated statements of consideration for that rule identified the 
1992 Edition with 1992 Addenda of Subsection IWE and Subsection IWL as 
the earliest version that the NRC found acceptable. A subsequent rule 
published on September 22, 1999 (64 FR 51370), included the 1995 
Edition with the 1996 Addenda as an acceptable edition of the ASME BPV 
Code. The statements of considerations for a later rule published on 
September 26, 2002 (67 FR 60520), noted that the 1992 Edition with the 
1992 Addenda, or the 1995 Edition with the 1996 Addenda of Subsection 
IWE and IWL must be used when implementing the initial 120-month 
interval for the ISI of Class MC and Class CC components, and that 
successive 120-month interval updates must be implemented in accordance 
with Sec.  50.55a(g)(4)(ii).
    This requirement was in place to expedite the initial containment 
examinations in accordance with Subsections IWE and IWL, which were 
required to be completed during the 5-year period from September 6, 
1996, to September 9, 2001. Now that there is an existing framework in 
place for containment examinations in accordance with Subsections IWE 
and IWL, there is no need for a condition specific to the initial 
examination interval. The examinations conducted during the initial 
interval can be conducted in accordance with Sec.  50.55a(g)(4).
10 CFR 50.55a(b)(2)(vii) Section XI Condition: Section XI References to 
OM Part 4, OM Part 6, and OM Part 10 (Table IWA-1600-1).
    The NRC is removing the existing condition Sec.  50.55a(b)(2)(vii). 
This paragraph describes the editions and addenda of the ASME OM Code 
to be used with the Section XI references to OM Part 4, OM Part 6, and 
OM Part 10 in Table IWA-1600-1 of Section XI. The condition is 
applicable to the ASME BPV Code, Section XI, Division 1, 1987 Addenda, 
1988 Addenda, or 1989 Edition. Paragraph (g)(4)(ii) requires that a 
licensee's successive 120-month inspection intervals comply with the 
requirements of the latest edition and addenda of the Code incorporated 
by reference in Sec.  50.55a(b)(2). Because licensees are no longer 
using these older editions and addenda of the Code referenced in this 
paragraph, this condition can be removed.
10 CFR 50.55a(b)(2)(ix) Metal Containment Examinations
    The NRC is revising Sec.  50.55a(b)(2)(ix), to require compliance 
with new condition Sec.  50.55a(b)(2)(ix)(K). The condition ensures 
containment leak-chase channel systems are properly inspected in 
accordance with the applicable requirements. The NRC specifies the 
application of this condition to all editions and addenda of Section 
XI, Subsection IWE, of the ASME BPV Code, prior to the 2017 Edition, 
that are incorporated by reference in paragraph (b) of Sec.  50.55a.
10 CFR 50.55a(b)(2)(ix)(K) Metal Containment Examinations
    The NRC is adding Sec.  50.55a(b)(2)(ix)(K) to ensure containment 
leak-chase channel systems are properly inspected.
    Regulations in Sec.  50.55a(g), ``Inservice Inspection 
Requirements,'' require that licensees implement the inservice 
inspection program for pressure retaining components and their integral 
attachments of metal containments and metallic liners of concrete 
containments in accordance with Subsection IWE of Section XI of the 
applicable edition and addenda of the ASME Code, incorporated by 
reference in paragraph (b) of Sec.  50.55a and subject to the 
applicable conditions in paragraph (b)(2)(ix). The regulatory condition 
in Sec.  50.55a(b)(2)(ix)(A) or equivalent provision in Subsection IWE 
of the ASME Code (2006 and later editions and addenda only) requires 
that licensees shall evaluate the acceptability of inaccessible areas 
when conditions exist in accessible areas that could

[[Page 26546]]

indicate the presence of, or result in, degradation to such 
inaccessible areas.
    The containment floor weld leak-chase channel system forms a metal-
to-metal interface with the containment shell or liner, the test 
connection end of which is at the containment floor level. Therefore, 
the leak-chase system provides a pathway for potential intrusion of 
moisture that could cause corrosion degradation of inaccessible 
embedded areas of the pressure-retaining boundary of the basemat 
containment shell or liner within it. In addition to protecting the 
test connection, the cover plates and plugs and accessible components 
of the leak-chase system within the access box are also intended to 
prevent intrusion of moisture into the access box and into the 
inaccessible areas of the shell/liner within the leak-chase channels, 
thereby protecting the shell and liner from potential corrosion 
degradation that could affect leak-tightness.
    The containment ISI program required by Sec.  50.55a to be 
implemented in accordance with Subsection IWE, of the ASME Code, 
Section XI, subject to regulatory conditions, requires special 
consideration of areas susceptible to accelerated corrosion degradation 
and aging, and barriers intended to prevent intrusion of moisture and 
water accumulation against inaccessible areas of the containment 
pressure-retaining metallic shell or liner. The containment floor weld 
leak-chase channel system is one such area subject to accelerated 
degradation and aging if moisture intrusion and water accumulation is 
allowed on the embedded shell and liner within it. Therefore, the leak-
chase channel system is subject to the inservice inspection 
requirements of Sec.  50.55a(g)(4).
    The NRC Information Notice (IN) 2014-07, ``Degradation of Leak-
Chase Channel Systems for Floor Welds of Metal Containment Shell and 
Concrete Containment Metallic Liner,'' (ADAMS Accession No. 
ML14070A114) discusses examples of licensees that did not conduct the 
required inservice inspections. The IN also summarizes the NRC's basis 
for including the leak-chase components within the scope of Subsection 
IWE, of the ASME Code, Section XI, and how licensees could fulfill the 
requirements. The NRC guidance explains that 100 percent of the 
accessible components of the leak-chase system should be inspected 
during each inspection period. There are three inspection periods in 
one ten-year inspection interval.
    After issuance of IN 2014-07, the NRC received feedback during a 
public meeting between NRC and ASME management, held on August 22, 2014 
(ADAMS Accession No. ML14245A003), noting that the IN guidance appeared 
to be in conflict with ASME Section XI Interpretation XI-1-13-10. In 
response to the comment during the public meeting, the NRC issued a 
letter to ASME (ADAMS Accession No. ML14261A051), which stated that the 
NRC found the provisions in the IN to be consistent with the 
requirements in the ASME Code; and the NRC may consider adding a 
condition to Sec.  50.55a to clarify the expectations. The ASME 
responded to the NRC's letter (ADAMS Accession No. ML15106A627) and 
noted that a condition in the regulations may be appropriate to clarify 
the NRC's position.
    Based on the operating experience summarized in IN 2014-07, and the 
industry feedback, the NRC has determined that a new condition is 
necessary in Sec.  50.55a(b)(2)(ix) to clarify the NRC's expectations 
and to ensure steel containment shells and liners receive appropriate 
examinations. In the 2017 Edition of the ASME Code, a provision was 
added that clearly specifies the examination of leak-chase channels. 
The provision requires 100 percent examination of the leak-chase 
channel closures over a ten-year inspection interval, as opposed to 100 
percent during each inspection period. Although the examination 
frequency is relaxed compared to the NRC's position as identified in IN 
2014-07, the NRC finds the provision in the 2017 Edition acceptable 
because the examination includes provisions for scope expansion and 
examinations of additional closures if degradation is identified within 
an inspection period. The NRC chose to align the condition with the 
acceptable provision in the latest approved edition of the ASME Code.
    This condition is applicable to all editions and addenda of the 
ASME Code prior to the 2017 Edition. The condition is being applied to 
all previous editions to clarify the NRC's position in the regulation. 
Licensees that are using a previous edition (i.e., an edition prior to 
the 2015 Edition that has been incorporated by reference previously) of 
the ASME Code for their current IWE inspection program interval may 
continue to conduct the required inspections in accordance with the 
NRC's position identified in IN 2014-17 (i.e., 100 percent examination 
every inspection period), or licensees may implement the condition as 
described in this rule, as long as they can demonstrate that 100 
percent of the inspections have been, or will be, completed within the 
current interval, as required by the condition.
10 CFR 50.55a(b)(2)(xvii) Section XI Condition: Reconciliation of 
Quality Requirements
    The NRC is removing the condition found in the current Sec.  
50.55a(b)(2)(xvii). This paragraph describes requirements for 
reconciliation of quality requirements when purchasing replacement 
items. When licensees use the 1995 Addenda through 1998 Edition of ASME 
BPV Code, Section XI, this condition required replacement items to be 
purchased in accordance with the licensee's quality assurance program 
description required by Sec.  50.34(b)(6)(ii), in addition to the 
reconciliation provisions of IWA-4200. The NRC has accepted without 
conditions the content of IWA-4200 in versions of the Code since the 
1999 Addenda of Section XI. Paragraph 50.55a(g)(4)(ii) requires that 
licensee's successive 120-month inspection intervals comply with the 
requirements of the latest edition and addenda of the Code incorporated 
by reference in Sec.  50.55a(b)(2). Subsequently, licensees are no 
longer using these older editions and addenda of the Code referenced in 
this paragraph therefore this condition can be removed. Section 
50.55a(b)(2)(xvii) is designated as [Reserved].
10 CFR 50.55a(b)(2)(xviii)(D) NDE Personnel Certification: Fourth 
Provision
    The NRC is amending the condition found in Sec.  
50.55a(b)(2)(xviii) to extend the applicability of the condition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section of ASME BPV Code, Section XI. This current 
condition prohibits those licensees which use ASME BPV Code, Section 
XI, 2011 Addenda through the 2013 Edition from using Appendix VII, 
Table VII-4110-1 and Appendix VIII, Subarticle VIII-2200. The condition 
requires licensees and applicants using these versions of Section XI to 
use the prerequisites for ultrasonic examination personnel 
certifications in Appendix VII, Table VII-4110-1 and Appendix VIII, 
Subarticle VIII-2200 in the 2010 Edition. This condition was added when 
the 2010 through the 2013 Edition was incorporated by reference. When 
ASME published the 2015 and 2017 Editions, Appendix VII, Table VII-
4110-1 and Appendix VIII, Subarticle VIII-2200 of ASME BPV Code, 
Section XI were not modified in a way that would make it possible for 
the NRC to remove this condition. Therefore, the NRC is amending this 
condition to extend the applicability to the latest

[[Page 26547]]

edition incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a.
10 CFR 50.55a(b)(2)(xx)(B) System Leakage Tests: Second Provision
    The NRC is amending the condition found in Sec.  
50.55a(b)(2)(xx)(B) to clarify the NRC's expectations related to the 
nondestructive examination (NDE) required when a system leakage test is 
performed (in lieu of a hydrostatic test) following repair and 
replacement activities performed by welding or brazing on a pressure 
retaining boundary using the 2003 Addenda through the latest edition 
and addenda of ASME BPV Code, Section XI incorporated by reference in 
paragraph (a)(1)(ii) of Sec.  50.55a. Industry stakeholders have 
expressed confusion as to what Code edition/addenda the requirements 
for NDE and pressure testing were required to satisfy. The NRC is 
modifying the condition to clarify that the NDE method (e.g., surface, 
volumetric, etc.) and acceptance criteria of the 1992 Edition or later 
of ASME BPV Code, Section III shall be met. The actual nondestructive 
examination and pressure testing may be performed using procedures and 
personnel meeting the requirements of the licensee's/applicant's 
current ISI code of record. This condition was first put in place by 
the NRC in a final rule that became effective October 10, 2008 (73 FR 
52730). The NRC determined the condition was necessary because the ASME 
BPV Code eliminated the requirement to perform the Section III NDE when 
performing a system leakage test in lieu of a hydrostatic test 
following repairs and replacement activities performed by welding or 
brazing on a pressure retaining boundary in the 2003 Addenda of ASME 
BPV Code, Section XI. When ASME published the 2015 Edition and the 2017 
Editions, IWA-4520 was not modified in a way that would make it 
possible for the NRC to remove this condition. Therefore, the NRC is 
amending this condition to extend the applicability to the latest 
edition incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a.
10 CFR 50.55a(b)(2)(xx)(C) System Leakage Tests: Third Provision
    The NRC is adding Sec.  50.55a(b)(2)(xx)(C) to provide two 
conditions for the use of the alternative Boiling Water Reactor (BWR) 
Class 1 system leakage test described in IWB-5210(c) and IWB-5221(d) of 
the 2017 Edition of ASME Section XI. The first condition addresses a 
prohibition against the production of heat through the use of a 
critical reactor core to raise the temperature of the reactor coolant 
and pressurize the reactor coolant pressure boundary (RCPB) (sometimes 
referred to as nuclear heat). The second condition addresses the 
duration of the hold time when testing non-insulated components to 
allow potential leakage to manifest itself during the performance of 
system leakage tests.
    The alternative BWR Class 1 system leakage test was intended to 
address concerns that performing the ASME-required pressure test for 
BWRs under shutdown conditions, (1) places the unit in a position of 
significantly reduced margin, approaching the fracture toughness limits 
defined in the Technical Specification Pressure-Temperature (P-T) 
curves, and (2) requires abnormal plant conditions/alignments, 
incurring additional risks and delays, while providing little added 
benefit beyond tests, which could be performed at slightly reduced 
pressures under normal plant conditions. However, due to restrictions 
imposed by the pressure control systems, most BWRs cannot obtain 
reactor pressure corresponding to 100 percent rated power during normal 
startup operations at low power levels that would be conducive to 
performing examinations for leakage. The alternative test would be 
performed at slightly reduced pressures and normal plant conditions, 
which the NRC finds will constitute an adequate leak examination and 
would reduce the risk associated with abnormal plant conditions and 
alignments.
    However, the NRC has had a longstanding prohibition against the 
production of heat through the use of a critical reactor core to raise 
the temperature of the reactor coolant and pressurize the RCPB for the 
purpose of pressure testing. A letter dated February 2, 1990, from 
James M. Taylor, Executive Director for Operations, NRC, to Messrs. 
Nicholas S. Reynolds and Daniel F. Stenger, Nuclear Utility Backfitting 
and Reform Group (ADAMS Accession No. ML14273A002), established the 
NRC's position with respect to use of a critical reactor core to raise 
the temperature of the reactor coolant and pressurize the RCPB for the 
purpose of pressure testing. In summary, the NRC's position is that 
testing under these conditions involves serious impediments to careful 
and complete inspections and therefore creates inherent uncertainty 
with regard to assuring the integrity of the RCPB. Further, the 
practice is not consistent with basic defense-in-depth safety 
principles.
    The NRC's position, established in 1990, was reaffirmed in IN No. 
98-13, ``Post-Refueling Outage Reactor Pressure Vessel Leakage Testing 
Before Core Criticality,'' dated April 20, 1998. The IN was issued in 
response to a licensee that had conducted an ASME BPV Code, Section XI, 
leakage test of the reactor pressure vessel (RPV) and subsequently 
discovered that it had violated 10 CFR part 50, appendix G, paragraph 
IV.A.2.d. This regulation states that pressure tests and leak tests of 
the reactor vessel that are required by Section XI of the ASME Code 
must be completed before the core is critical. The IN references NRC 
Inspection Report 50-254(265)-97027 (ADAMS Accession No. ML15216A276), 
which documents that licensee personnel performing VT-2 examinations of 
the drywell at one BWR plant covered 50 examination areas in 12 
minutes, calling into question the adequacy of the VT-2 examinations.
    The bases for the NRC's historical prohibition of pressure testing 
with the core critical are summarized as follows:
    1. Nuclear operation of a plant should not commence before 
completion of system hydrostatic and leakage testing to verify the 
basic integrity of the RCPB, a principal defense-in-depth barrier to 
the accidental release of fission products. In accordance with the 
defense-in-depth safety precept, the nuclear power plant design 
provides for multiple barriers to the accidental release of fission 
products from the reactor.
    2. Hydrotesting must be done essentially water solid (i.e., free of 
pockets of air, steam or other gases) so that stored energy in the 
reactor coolant is minimized during a hydrotest or leaktest.
    3. The elevated reactor coolant temperatures, associated with 
critical operation, result in a severely uncomfortable and difficult 
working environment in plant spaces where the system leakage 
inspections must be conducted. The greatly increased stored energy in 
the reactor coolant, when the reactor is critical, increases the hazard 
to personnel and equipment in the event of a leak. As a result, the 
ability for plant workers to perform a comprehensive and careful 
inspection becomes greatly diminished.
    However, the NRC has determined that pressure testing with the core 
critical is acceptable under the following conditions: when performed 
after repairs of a limited scope; where only a few locations or a 
limited area needs to be examined; and when ASME Code Section XI, Table 
IWB-2500-1, Category B-P (the pressure test required once per cycle of 
the entire RCPB) has been recently performed verifying the integrity of 
the overall RCPB. The NRC

[[Page 26548]]

also notes the alternative BWR Class 1 system leakage test does not 
allow for the use of the alternative test pressure following repairs/
replacements on the RPV; therefore, it does not violate 10 CFR part 50, 
appendix G. The NRC has determined that the risk associated with 
nuclear heat at low power is comparable with the risk to the plant when 
the test is performed without nuclear heat (with the core subcritical) 
during mid-cycle outages, when decay heat must be managed. Performing 
the pressure test under shutdown conditions at full operating pressure 
without nuclear heat requires securing certain key pressure control, 
heat removal, and safety systems. It is more difficult to control 
temperature and pressure when there is significant production of decay 
heat (e.g., after a mid-cycle outage), and may reduce the margin 
available to prevent exceeding the plant pressure-temperature limits.
    When the pressure test is conducted using nuclear heat, the scope 
of repairs should be relatively small in order to minimize the 
personnel safety risk and to avoid rushed examinations. The alternative 
BWR Class 1 system leakage test does not place any restrictions on the 
size or scope of the repairs for which the alternative may be used, 
provided the alternative test pressure is not used to satisfy pressure 
test requirements following repair/replacement activities on the 
reactor vessel. It is impractical to specify a particular number of 
welded or mechanical repairs that would constitute a ``limited scope.'' 
However, if the plant is still in a refueling outage and has already 
performed the ASME Section XI Category B-P pressure test of the entire 
RCPB, it is likely that subsequent repairs would be performed only on 
an emergent basis, and would generally be of a limited scope. 
Additionally, the overall integrity of the RCPB will have been recently 
confirmed via the Category B-P test. For mid-cycle maintenance outages, 
the first condition allows the use of nuclear heat to perform the test, 
if the outage duration is 14 days or less. This would tend to limit the 
scope of repairs, and also limit the use of the code case to outages 
where there is a significant production of decay heat. Therefore, the 
first condition on the alternative BWR Class 1 system leakage test 
states: ``The use of nuclear heat to conduct the BWR Class 1 system 
leakage test is prohibited (i.e. the reactor must be in a non-critical 
state), except during refueling outages in which the ASME Section XI 
Category B-P pressure test has already been performed, or at the end of 
mid-cycle maintenance outages fourteen (14) days or less in duration.''
    With respect to the second condition and adequate pressure test 
hold time, the technical analysis supporting the alternative BWR Class 
1 system leakage test indicates that the lower test pressure provides 
more than 90 percent of the flow that would result from the pressure 
corresponding to 100 percent power. However, a reduced pressure means a 
lower leakage rate, so additional time is required in order for there 
to be sufficient leakage to be observed by inspection personnel. 
Section XI, paragraph IWA-5213, ``Test Condition Holding Time,'' does 
not require a holding time for Class 1 components, once test pressure 
is obtained. To account for the reduced pressure, the alternative BWR 
Class 1 system leakage test would require a 15-minute hold time for 
non-insulated components. The NRC has determined that 15 minutes does 
not allow for an adequate examination because it is not possible to 
predict the entire range of scenarios or types of defects that could 
result in leakage. Some types of defects could result in immediate 
leakage, such as an improperly torqued bolted connection; however other 
types of defects, such as weld defects or tight cracks, could present a 
more torturous path for leakage and result in delayed leakage. Due to 
the uncertainty in the amount of time required for leakage to occur to 
an extent that it would be readily detectable by visual examination, 
the NRC has determined that it is appropriate to conservatively specify 
a longer hold time of 1 hour for non-insulated components. Therefore, 
the second condition for the alternative BWR Class 1 system leakage 
test requires a 1 hour hold time for non-insulated components.
10 CFR 50.55a(b)(2)(xxi) Section XI Condition: Table IWB-2500-1 
Examination Requirements
    The NRC is removing the condition found in Sec.  
50.55a(b)(2)(xxi)(A) to allow licensees to use the current editions of 
ASME BPV Code, Section XI, Table IWB 2500-1, Examination Category B-D, 
Full Penetration Welded Nozzles in Vessels, Items B3.40 and B3.60 
(Inspection Program A) and Items B3.120 and B3.140 (Inspection Program 
B). These inspection categories concern pressurizer and steam generator 
nozzle inner radius section examinations. Previously, the condition 
required licensees to use the 1998 Edition, which required examination 
of the nozzle inner radius when using the 1999 Addenda through the 
latest edition and addenda incorporated by reference in paragraph 
(a)(1)(ii) of Sec.  50.55a. As these inspection requirements were 
removed in the ASME BPV Code in 1999, this change eliminates the 
requirement to examine the nozzle inner radii in steam generators and 
pressurizers.
    The requirements for examinations of inner nozzle radii in several 
components were developed in the ASME BPV Code in reaction to the 
discovery of thermal fatigue cracks in the inner radius section of 
boiling water reactor feedwater nozzles in the late 1970's and early 
1980's. As described in NUREG/CR-7153, ``Expanded Materials Degradation 
Assessment (EMDA),'' (ADAMS Accession Nos. ML14279A321, ML14279A461, 
ML14279A349, ML14279A430, and ML14279A331), and NUREG-0619-Rev-1, ``BWR 
Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking: 
Resolution of Generic Technical Activity A-10 (Technical Report),'' 
(ADAMS Accession No. ML031600712), the service-induced flaws that have 
been observed are cracks at feedwater nozzles associated with mixing of 
lower-temperature water with hot water in a BWR vessel with rare 
instances of underclad and shallow cladding cracking appearing in 
pressurized water reactor (PWR) nozzles. Feedwater nozzle inner radius 
cracking has not been detected since the plants changed operation of 
the low flow feedwater controller. Significant inspections and repairs 
were required in the late 1970s and early 1980s to address these 
problems. The redesign of safe end/thermal sleeve configurations and 
feedwater spargers, coupled with changes in operating procedures, has 
been effective to date. No further occurrences of nozzle fatigue 
cracking have been reported for PWRs or BWRs.
    When the new designs and operating procedures appeared to have 
mitigated the nozzle inner radius cracking, the ASME BPV Code, Section 
XI requirements to inspect steam generator and pressurizer nozzle inner 
radii were removed in the 1999 Addenda of ASME BPV Code, Section XI. 
Since the NRC imposed the condition requiring that these areas be 
inspected in 2002, no new cracking has been identified in steam 
generator or pressurizer nozzle inner radii. The NRC finds that the 
complete absence of cracking since the operational change provides 
reasonable assurance that the observed cracking was the result of 
operational practices that have been discontinued. Because the inner 
radius inspections were instituted solely based on the observed 
cracking and since the cracking mechanism has now been resolved through 
changes in operation, the NRC

[[Page 26549]]

finds that the intended purpose of the steam generator and pressurizer 
inner radius exams no longer exists and that the exams can be 
discontinued. In addition to operating experience, the NRC has reviewed 
the nozzle inner radii examinations as part of approving alternatives 
and granting relief requests concerning inspections of the pressurizer 
and steam generator nozzle inner radii. In the safety evaluations for 
proposed alternatives, the NRC has concluded that the fatigue analysis 
for a variety of plants shows that there is reasonable assurance that 
there will not be significant cracking at the steam generator or 
pressurizer nozzle inner radii before the end of the operating licenses 
of the nuclear power plants.
    Therefore, based on the design changes, operating experiences, and 
analysis done by industry and the NRC, the NRC is removing Sec.  
55.55a(b)(2)(xxi)(A), which requires the inspection of pressurizer and 
steam generator nozzle inner radii.
10 CFR 50.55a(b)(2)(xxi)(B) Table IWB-2500-1 Examination Requirements
    The NRC is adding a new paragraph (b)(2)(xxi)(B) that places 
conditions on the use of the provisions of IWB-2500(f) and (g) and 
Notes 6 and 7 of Table IWB-2500-1 of the 2017 Edition of ASME BPV Code, 
Section XI. These provisions allow licensees of BWRs to reduce the 
number of Item Number B3.90 and B3.100 components to be examined from 
100 percent to 25 percent. These conditions require licensees using the 
provisions of IWB-2500(f) to maintain the evaluations that determined 
the plant satisfied the criteria of IWB-2500(f) as records in 
accordance with IWA-1400. The conditions prohibit use of a new 
provision in Section XI, 2017 Edition, Table 2500-1 Category B-D, Full 
Penetration Welded Nozzles in Vessels, Items B3.90 and B3.100, specific 
to BWR nuclear power plants with renewed operating licenses or renewed 
combined licensees in accordance with 10 CFR part 54. The final 
condition does not allow the use of these provisions to eliminate 
preservice or inservice volumetric examinations of plants with a 
Combined Operating License pursuant to 10 CFR part 52, or a plant that 
receives its operating license after October 22, 2015.
    The addition of these provisions addresses the incorporation of 
Code Case N-702, ``Alternative Requirements for Boiling Water Reactor 
(BWR) Nozzle Inner Radius and Nozzle-to-Shell Welds Section XI, 
Division 1,'' into the Code. The conditions are consistent with those 
in Regulatory Guide (RG) 1.147, ``Inservice Inspection Code Case 
Acceptability, ASME Section XI, Division 1,'' Revision 19.
    The NRC finds that eliminating the volumetric preservice or 
inservice examination, as allowed by implementing the provisions of 
IWB-2500(g) and Note 7 of Table IWB-2500-1, is predicated on good 
operating experience for the existing fleet, which has not found any 
inner radius cracking in the nozzles within scope of the code case. New 
reactor designs do not have any operating experience; therefore, the 
condition ensures that new reactors will perform volumetric 
examinations of nozzle inner radii to gather operating experience.
10 CFR 50.55a(b)(2)(xxv) Section XI Condition: Mitigation of Defects by 
Modification
    The NRC is amending the condition found in Sec.  50.55a(b)(2)(xxv) 
to allow the use of IWA-4340 of ASME BPV Code, Section XI, 2011 Addenda 
through 2017 Edition with conditions. The modification of Sec.  
50.55a(b)(2)(xxv) adds paragraph (A) and continues the prohibition of 
IWA-4340 for Section XI editions and addenda prior to the 2011 Addenda. 
It adds paragraph (B), which contains the five conditions that the NRC 
is proposing to place on the use of IWA-4340 of Section XI, 2011 
Addenda through 2017 Edition. In response to public comments, the NRC 
modified the third condition and added the fourth and fifth conditions.
10 CFR 50.55a(b)(2)(xxv)(A) Mitigation of Defects by Modification: 
First Provision
    The NRC is adding paragraph (b)(2)(xxv)(A), which continues the 
prohibition of IWA-4340 for Section XI editions and addenda prior to 
the 2011 Addenda. IWA-4340 as originally incorporated into Section XI, 
Subsubarticle IWA-4340 did not include critical requirements that were 
incorporated into later editions of Section XI such as: (a) 
Characterization of the cause and projected growth of the defect; (b) 
verification that the flaw is not propagating into material credited 
for structural integrity; (c) prohibition of repeated modifications 
where a defect area grew into the material required for the 
modification; and (d) pressure testing. Therefore, the NRC prohibited 
the use of IWA-4340 in its original form. This new paragraph is 
necessary to maintain the prohibition because the NRC, as described in 
the following paragraph, is allowing the use of IWA-4340 of Section XI, 
2011 Addenda through 2017 Edition.
10 CFR 50.55a(b)(2)(xxv)(B) Mitigation of Defects by Modification: 
Second Provision
    The NRC is adding paragraph (b)(2)(xxv)(B) to allow the use of IWA-
4340 of Section XI, 2011 Addenda through 2017 Edition with five 
conditions. The NRC finds that IWA-4340 as incorporated into later 
editions of Section XI was improved with requirements such as: (a) 
Characterization of the cause and projected growth of the defect; (b) 
verification that the flaw is not propagating into material credited 
for structural integrity; (c) prohibition of repeated modifications 
where a defect area grew into the material required for the 
modification; and (d) pressure testing. With inclusion of these 
requirements and those stated in the following conditions, the NRC 
concludes that there are appropriate requirements in place to provide 
reasonable assurance that the modification will provide an adequate 
pressure boundary, even while considering potential growth of the 
defect. The conditions and the basis for each are as follows:
     The first condition prohibits the use of IWA-4340 on 
crack-like defects or those associated with flow accelerated corrosion. 
The design requirements and potentially the periodicity of follow-up 
inspections might not be adequate for crack-like defects that could 
propagate much faster than defects due to loss of material. Therefore, 
the NRC is prohibiting the use of IWA-4340 on crack-like defects. Loss 
of material due to flow accelerated corrosion is managed by licensee 
programs based on industry standards. The periodicity of follow-up 
inspections is best managed by plant-specific flow accelerated 
corrosion programs. In addition, subparagraph IWA-4421(c)(2) provides 
provisions for restoring minimum required wall thickness by welding or 
brazing, including loss of material due to flow accelerated corrosion.
     The second condition requires the design of a modification 
that mitigates a defect to incorporate a loss of material rate either 2 
times the actual measured corrosion rate in the location, or 4 times 
the estimated maximum corrosion rate for the piping system. Corrosion 
rates are influenced by local conditions (e.g., flow rate, 
discontinuities). The condition to extrapolate a loss of material rate 
either 2 times the actual measured corrosion rate in the location, or 4 
times the estimated maximum corrosion rate for the system is consistent 
with ASME Code Cases N-786-1, ``Alternative Requirements for

[[Page 26550]]

Sleeve Reinforcement of Class 2 and 3 Moderate Energy Carbon Steel 
Piping,'' and N-789, ``Alternative Requirements for Pad Reinforcement 
of Class 2 and 3 Moderate Energy Carbon Steel Piping for Raw Water 
Service.''
     The third condition requires the licensee to perform a 
wall thickness examination in the vicinity of the modification and 
relevant pipe base metal during each refueling outage cycle to detect 
propagation of the defect into the material credited for structural 
integrity of the item, unless the examinations in the two refueling 
outage cycles subsequent to the installation of the modification are 
capable of validating the projected flaw growth. Where the projected 
flaw growth has been validated, the modification shall be examined at 
half its expected life or once per interval whichever is smaller. The 
NRC concludes that the provision allowed by subparagraph IWA-4340(g) to 
conduct follow-up wall thickness measurements only to the extent that 
they demonstrate that the defect has not propagated into the material 
credited for structural integrity is not sufficient because it does not 
provide a verification of the projected flaw growth. Subparagraph IWA-
4340(h) does not fully address the NRC's concern because it allows for 
projected flaw growth to be based on ``prior Owner or industry 
experiences with the same conditions'' instead of specific measurements 
in the location of the modification. The condition allows for only 
conducting examinations in the two refueling outages subsequent to the 
installation of the modification, consistent with subparagraph IWA-
4340(g), if the measurements are capable of projecting the flaw growth. 
In response to public comments on the proposed condition, the NRC 
recognized that the requirement in IWA-4340(i) to conduct an 
examination at the modification location every interval could be 
interpreted to not be required based on the ``practicality'' statement 
in the cross referenced IWA-4340(g). The NRC has concluded that even if 
the flaw growth has been confirmed, and as a result, refueling outage 
interval inspections are not being conducted, over time, flaw growth 
rates could possibly accelerate. Although there is significant margin 
in the analyses, the NRC added a requirement to this condition to 
examine the modification at half its expected life or once per 
interval, whichever is smaller, to ensure that the potential effect of 
varying flaw growth rates is managed.
    In response to public comments on the proposed condition, the NRC 
recognized that it may be onerous to perform follow-up examinations 
every refueling outage for modifications installed in inaccessible 
locations. The NRC is adding exceptions to the condition for buried 
pipe locations at potentially reduced intervals. One exception allows 
wall thickness measurements at a comparable accessible piping location 
where loss of material has occurred due to internal corrosion and the 
second addresses loss of material due to external corrosion.
     For buried pipe locations where the loss of material has 
occurred due to internal corrosion, the refueling outage interval wall 
thickness examinations may be conducted at a different location in the 
same system as long as: (a) Wall thickness measurements were conducted 
at the different location at the same time as installation of the 
modification; (b) the flow profile and flow characteristics are similar 
at the different location; (c) the piping configuration is the same 
(e.g., straight run of pipe, elbow, tee), and (d) if pitting occurred 
at the modification location, but not at the different location, wall 
loss values must be multiplied by four. Where wall loss values are 
greater than that assumed during the design of the modification, the 
structural integrity of the modification shall be reanalyzed. 
Additionally, if the extent of degradation is different (i.e., through 
wall, percent wall loss plus or minus 25 percent) or the corrosion 
mechanism (e.g., general, pitting) is not the same at the different 
location as at the modification location, the modification must be 
examined at half its expected life or 10 years, whichever is smaller.
     For buried pipe locations where loss of material has 
occurred due to external corrosion, the modification must be examined 
at half its expected life or 10 years, whichever is smaller. The NRC 
staff included this condition because for external corrosion, there is 
no comparable accessible location.
10 CFR 50.55a(b)(2)(xxvi) Section XI Condition: Pressure Testing Class 
1, 2 and 3 Mechanical Joints
    The NRC is amending the condition found in Sec.  50.55a(b)(2)(xxvi) 
to clarify the NRC's expectations related to the pressure testing of 
ASME BPV Code Class 1, 2, and 3 mechanical joints disassembled and 
reassembled during the performance of an ASME BPV Code, Section XI 
activity. Industry stakeholders have expressed confusion with the 
current regulatory requirements with regard to when a pressure test is 
required and which year of the Code the pressure testing should be in 
compliance with in accordance with this condition. The NRC is modifying 
the condition to clarify that all mechanical joints in Class 1, 2 and 3 
piping and components greater than NPS-1 that are disassembled and 
reassembled during the performance of a Section XI activity (e.g., a 
repair/replacement activity requiring documentation on a Form NIS-2) 
shall be pressure tested in accordance with IWA-5211(a). The pressure 
testing shall be performed using procedures and personnel meeting the 
requirements of the licensee's/applicant's current code of record. This 
condition was first put in place by the NRC in the final rule effective 
November 1, 2004 (69 FR 58804). The NRC determined that the condition 
was necessary because the ASME BPV Code eliminated the requirements to 
pressure test Class 1, 2, and 3 mechanical joints undergoing repair and 
replacement activities in the 1999 Addenda. The NRC finds that pressure 
testing of mechanical joints affected by repair and replacement 
activities is necessary to ensure and verify the leaktight integrity of 
the system pressure boundary.
10 CFR 50.55a(b)(2)(xxxii) Section XI Condition: Summary Report 
Submittal
    The NRC is amending the condition found in Sec.  
50.55a(b)(2)(xxxii) to address the use of Owner Activity Reports. 
Through the 2009 Edition of ASME BPV Code, Section XI, Owners were 
required to prepare Summary Reports of preservice and inservice 
examinations and repair replacement activities. This condition was 
added when the 2010 and the 2013 Edition was incorporated by reference 
because up until that time, Owners were required to submit these 
reports to the regulatory authority having jurisdiction of the plant 
site. The 2010 Edition removed the requirement for submittal from IWA-
6240(c), to state that submittal was only mandatory if required by the 
authority. The NRC added the condition in paragraph (b)(2)(xxxii) to 
require submittal of Summary Reports. In the 2015 Edition of ASME BPV 
Code, Section XI the title of these reports was changed from Summary 
Reports to Owner Activity Reports. Therefore, the NRC is amending the 
condition to also require the submittal of Owner Activity Reports.
10 CFR 50.55a (b)(2)(xxxiv) Section XI Condition: Nonmandatory Appendix 
U
    The NRC is amending the requirements in current paragraph 
(b)(2)(xxxiv) to make the condition applicable to the latest edition 
incorporated by reference in paragraph (a)(1)(ii) of Sec.  50.55a. The 
current condition in paragraph (b)(2)(xxxiv)(A)

[[Page 26551]]

requires repair and replacement activities temporarily deferred under 
the provisions of Nonmandatory Appendix U to be performed during the 
next scheduled refueling outage. This condition was added when the 2013 
Edition was incorporated by reference. When ASME published the 2015 
Edition and the 2017 Edition, Nonmandatory Appendix U was not modified 
in a way that would make it possible for the NRC to remove this 
condition. Therefore, the NRC is modifying this condition to make it 
apply to the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of Sec.  50.55a.
    The current condition in paragraph (b)(2)(xxxiv)(B) requires a 
mandatory appendix in ASME Code Case N-513-3 to be used as the 
referenced appendix for paragraph U-S1-4.2.1(c). This condition was 
also added when the 2013 Edition was incorporated by reference. The 
omission that made this condition necessary was remedied in the 2017 
Edition. Therefore, the NRC is modifying this condition to make it 
apply only to the 2013 and the 2015 Editions.
10 CFR 50.55a(b)(2)(xxxv) Section XI Condition: Use of RTT0 
in the KIa and KIc Equations
    The NRC is redesignating the requirements in current paragraph 
(b)(2)(xxxv), that address the use of the 2013 Edition of ASME BPV 
Code, Section XI, Appendix A, paragraph A-4200, as (b)(2)(xxxv)(A). The 
ASME BPV Code has addressed the NRC concern related to this condition 
in the 2015 Edition; however, it is still relevant to licensees/
applicants using the 2013 Edition. The NRC is adding a new paragraph 
(b)(2)(xxv)(B) to condition the use of 2015 Edition of ASME BPV Code, 
Section XI, Appendix A, paragraph A-4200(c), to require the use of the 
equation RTKIa = T0 + 90.267 exp(-
0.003406T0) for U.S. Customary Units (U.S. Units) in lieu of 
the equation shown in the Code. Paragraph A-4200(c) was added in the 
2015 Edition to provide for an alternative method in establishing a 
fracture-toughness-based reference temperature, RTT0, for 
pressure retaining materials, using fracture toughness test data. The 
equation shown for the International System of Units (SI Units) was 
derived from test data. The equation shown for U.S. Units was a 
converted version of the equation shown for the SI Units. 
Unfortunately, an error was made in the conversion, which makes the 
equation shown for U.S. Units incorrect. The equation shown above in 
this paragraph for RTKIa is the correct formula for U.S. 
Units.
10 CFR 50.55a(b)(2)(xxxvi) Section XI Condition: Fracture Toughness of 
Irradiated Materials
    The NRC is amending the condition found in Sec.  
50.55a(b)(2)(xxxvi) to extend the applicability to use of the 2015 and 
2017 Editions of ASME BPV Code, Section XI. This current condition 
requires licensees using ASME BPV Code, Section XI, 2013 Edition, 
Appendix A, paragraph A-4400, to obtain NRC approval before using 
irradiated T0 and the associated RTT0 in 
establishing fracture toughness of irradiated materials. This condition 
was added when the 2013 Edition was incorporated by reference because 
the newly introduced A-4200(b) could mislead the users of Appendix A 
into adopting methodology that is not accepted by the NRC. When ASME 
published the 2015 Edition and the 2017 Edition, Appendix A of the ASME 
BPV Code, Section XI was not modified in a way that would make it 
possible for the NRC to remove this condition. Therefore, the NRC is 
modifying this condition to make it apply to the 2015 and 2017 
Editions.
10 CFR 50.55a(b)(2)(xxxviii) Section XI Condition: ASME Code Section XI 
Appendix III Supplement 2
    The NRC is adding Sec.  50.55a(b)(2)(xxxviii) to condition ASME BPV 
Code, Section XI Appendix III Supplement 2. Supplement 2 is closely 
based on ASME Code Case N-824, ``Ultrasonic Examination of Cast 
Austenitic Piping Welds From the Outside Surface Section XI, Division 
1,'' which was incorporated by reference with conditions in Sec.  
50.55a(b)(2)(xxxvii). The conditions on ASME BPV Code, Section XI 
Appendix III Supplement 2 are consistent with the conditions on ASME 
Code Case N-824, published in July 18, 2017 (82 FR 32934).
    The conditions are derived from research into methods for 
inspecting Cast Austenitic Stainless Steel (CASS) components; these 
methods are published in NUREG/CR-6933, ``Assessment of Crack Detection 
in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-
Frequency Ultrasonic Methods,'' (ADAMS Accession Nos. ML071020410 and 
ML071020414), and NUREG/CR-7122, ``An Evaluation of Ultrasonic Phased 
Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge 
Line Piping Welds,'' (ADAMS Accession No. ML12087A004). These NUREG/CR 
reports show that CASS materials less than 1.6 inches thick can be 
reliably inspected for flaws 10 percent through wall or deeper if 
encoded phased array examinations are performed using low ultrasonic 
frequencies and a sufficient number of inspection angles. Additionally, 
for thicker welds, flaws greater than 30 percent through wall in depth 
can be detected using low-frequency encoded phased array ultrasonic 
inspections.
    The NRC, using NUREG/CR-6933 and NUREG/CR-7122, has determined that 
sufficient technical basis exists to condition ASME BPV Code, Section 
XI, Appendix III Supplement 2. The NUREG/CR reports show that CASS 
materials produce high levels of coherent noise and that the noise 
signals can be confusing and mask flaw indications. The optimum 
inspection frequencies for examining CASS components of various 
thicknesses as described in NUREG/CR-6933 and NUREG/CR-7122 are 
reflected in condition Sec.  50.55a(b)(2)(xxxviii)(A). As NUREG/CR-6933 
shows that the grain structure of CASS can reduce the effectiveness of 
some inspection angles, the NRC finds sufficient technical basis for 
the use of ultrasound using angles including, but not limited to, 30 to 
55 degrees, with a maximum increment of 5 degrees. This is reflected in 
condition Sec.  50.55a(b)(2)(xxxviii)(B).
10 CFR 50.55a(b)(2)(xxxix)(A) Defect Removal: First Provision
    The NRC is adding Sec.  50.55a(b)(2)(xxxix)(A) to place conditions 
on the use of ASME BPV Code, Section XI, IWA-4421(c)(1). The condition 
establishes that the final configuration of the item will be in 
accordance with the original Construction Code, later editions and 
addenda of the Construction Code, or a later different Construction 
Code, as well as meeting the Owner's Requirements or revised Owner's 
Requirements. This condition ensures that welding, brazing, 
fabrication, and installation requirements, as well as design 
requirements for material, design or configuration changes, are 
consistent with the Construction Code and Owner's Requirements. This 
condition retains the intent of the revision to Section XI that: (a) 
Replacements in kind are acceptable; (b) replacements with alternative 
configurations are acceptable as long as Construction Code and Owner's 
Requirements are met; and (c) defect removal is required; however, this 
can be accomplished by replacing all or a portion of the item 
containing the defect.

[[Page 26552]]

10 CFR 50.55a(b)(2)(xxxix)(B) Defect Removal: Second Provision
    The NRC is adding Sec.  50.55a(b)(2)(xxxix)(B) to place conditions 
on the use of ASME BPV Code, Section XI, IWA-4421(c)(2). The inclusion 
of subparagraph IWA-4421(c)(2) is intended to address wall thickness 
degradation where the missing wall thickness is restored by weld metal 
deposition. This repair activity restores the wall thickness to an 
acceptable condition; however, it does not ``remove'' the degraded wall 
thickness (i.e., the defect); rather, restoration of wall thickness by 
welding or brazing mitigates the need to remove the defect. The NRC 
finds that increasing the wall thickness of an item to reclassify a 
crack from a defect to a flaw \3\ is not acceptable because there are 
no provisions in subparagraph IWA-4421(c)(2) for analyses and ongoing 
monitoring of potential crack growth. Therefore, this condition 
prohibits the use of subparagraph IWA-4421(c)(2) rather than 
replacement for crack-like defects.
---------------------------------------------------------------------------

    \3\ As defined in ASME BPV Code, Section XI, Article IWA-9000, a 
``flaw'' is as an imperfection or unintentional discontinuity that 
is detectable by nondestructive examination and a ``defect'' is 
defined as a flaw of such size, shape, orientation, location, or 
properties as to be rejectable.
---------------------------------------------------------------------------

10 CFR 50.55a(b)(2)(xl) Section XI Condition: Prohibitions on Use of 
IWB-3510.4(b)
    The NRC is adding Sec.  50.55a(b)(2)(xl) to prohibit the use of 
ASME BPV Code, Section XI, 2017 Edition, Subparagraphs IWB-3510.4(b)(4) 
and IWB-3510.4(b)(5), which allow use of certain acceptance standard 
tables for high yield strength ferritic materials because they are not 
supported by the fracture toughness data.
    The ASME BPV Code, Section XI, Subarticle IWB-3500 provides 
acceptance standards for pressure retaining components made of ferritic 
steels. Subparagraph IWB-3510.4 specifies material requirements for 
ferritic steels for application of the acceptance standards. In prior 
editions of the ASME BPV Code, Section XI, the material requirements 
for ferritic steels for which the acceptance standards of IWB-3500 
apply are included in a note under the title of tables that specify 
allowable flaw sizes (e.g., Table IWB-3510-1 ``Allowable Planar 
Flaws''). Subparagraph IWB-3510.4 separates ferritic materials into 
three groups: (a) Those with a minimum yield strength of 50 ksi or 
less, (b) five ferritic steels with these material designations: SA-508 
Grade 2 Class 2 (former designation: SA-508 Class 2a), SA-508 Grade 3 
Class 2 (former designation: SA-508 Class 3a), SA-533 Type A Class 2 
(former designation: SA-533 Grade A Class 2), SA-533 Type B Class 2 
(former designation: SA-533 Grade B Class 2), and SA-508 Class 1, and 
(c) those with greater than 50 ksi but not exceeding 90 ksi. The 
material requirements for ferritic steels with a minimum yield strength 
of 50 ksi or less and those with greater than 50 ksi but not exceeding 
90 ksi are explicitly specified. However, there are no material 
requirements for the five ferritic steels identified above.
    The NRC finds Subparagraph IWB-3510.4(a) acceptable because it is 
consistent with the current material requirements for ferritic steels 
having a minimum yield strength of 50 ksi or less. The NRC finds 
Subparagraph IWB-3510.4(c) acceptable because it is consistent with the 
current material requirements for ferritic steels having a minimum 
yield strength of greater than 50 ksi to 90 ksi.
    The NRC does not find subparagraphs IWB-3510.4(b)(4) and (5) 
acceptable for the following reasons. The NRC plotted the ASME BPV 
Code, Section XI static plain-strain fracture toughness 
(KIc) curve in relevant figures in an ASME conference paper, 
PVP2010-25214, ``Fracture Toughness of Pressure Boundary Steels with 
Higher Yield Strength'' that shows dynamic fracture toughness 
(KId) data for materials listed in IWB-3510.4 (b)(1) to IWB-
3510.4 (b)(4). The NRC confirmed that the materials listed in IWB-
3510.4 (b)(1) and IWB-3510.4 (b)(3) are acceptable because the data are 
above the KIC curve with adequate margin to compensate for 
the limited size of the data set. Additionally, the NRC has approved 
the use of the materials listed in IWB-3510.4 (b)(1) and IWB-3510.4 
(b)(3) in a licensing and a design certification application. For the 
material listed in IWB-3510.4 (b)(2), KId data was 
demonstrated to be above the crack arrest fracture toughness 
(KIa). The NRC has previously determined the KIa 
fracture toughness standard to be acceptable. Hence, the materials 
listed in IWB-3510.4 (b)(2) are acceptable. However, the technical 
basis document does not provide sufficient data to support exclusion of 
the fracture toughness requirements for the materials specified in 
Subparagraphs IWB-3510.4(b)(4) and IWB-3510.4(b)(5).
    This condition does not change the current material requirements 
because licensees/applicants may continue to use testing to show that 
the two prohibited materials meet the material requirements.
10 CFR 50.55a(b)(2)(xli) Section XI Condition: Preservice Volumetric 
and Surface Examinations Acceptance
    The NRC is adding Sec.  50.55a(b)(2)(xli) to prohibit the use of 
ASME BPV Code, Section XI, Subparagraphs IWB-3112(a)(3) and IWC-
3112(a)(3) in the 2013 through 2017 Edition. The NRC is prohibiting 
these items consistent with a final rule that approved ASME BPV Code 
Cases for use, dated January 17, 2018, (83 FR 2331).
    During the review of public comments that were submitted on the 
proposed rule, dated March 2, 2016, (81 FR 10780), the NRC identified 
inconsistencies between Regulatory Guide 1.193, ``ASME Code Cases Not 
Approved for Use,'' Revision 5, and a then concurrent proposed rule to 
incorporate by reference the 2009-2013 Editions of the ASME BPV Code 
(80 FR 56819), dated December 2, 2015.
    Specifically, conditions that pertain to the NRC's disapproval of 
Code Case N-813, ``Alternative Requirements for Preservice Volumetric 
and Surface Examination,'' in the ASME BPV Code Regulatory Guide 1.193 
proposed rule were not included in the ASME BPV 2009-2013 Editions 
proposed rule; however, the content of Code Case N-813 had been 
incorporated in the 2013 Edition of the ASME Code, Section XI. In order 
to resolve this conflict, the NRC excluded from the incorporation by 
reference those applicable portions of Section IX in the 2011a Addenda 
and the 2013 Edition, in Sec.  50.55a(a)(1)(ii)(C)(52) and (53) 
respectively. This allowed the NRC to develop an appropriate regulatory 
approach for the treatment of these provisions that is consistent with 
the ASME BPV Code Regulatory Guide 1.193 rulemaking, in which the NRC 
found the acceptance of preservice flaws by analytical evaluation 
unacceptable.
    Code Case N-813 is a proposed alternative to the provisions of the 
2010 Edition of the ASME Code, Section XI, paragraph IWB-3112. 
Paragraph IWB-3112 does not allow the acceptance of flaws detected in 
the preservice examination by analytical evaluation. Code Case N-813 
would allow the acceptance of these flaws through analytical 
evaluation. Per paragraph IWB-3112, any preservice flaw that exceeds 
the acceptance standards of Table IWB-3410-1 must be removed. While it 
is recognized that operating experience has shown that large through-
wall flaws and leakages have developed in previously repaired welds as 
a result of weld residual stresses, the NRC has the following concerns

[[Page 26553]]

regarding the proposed alternative in Code Case N-813:
    (1) The requirements of paragraph IWB-3112 were developed to ensure 
that defective welds were not placed in service. The NRC finds that a 
preservice flaw detected in a weld that exceeds the acceptance 
standards of Table IWB-3410-1 demonstrates poor workmanship and/or 
inadequate welding practice and procedures. The NRC finds that such an 
unacceptable preservice flaw needs to be removed and the weld needs to 
be repaired before it is placed in service.
    (2) Under Code Case N-813 Paragraph B-3112(a)(3), large flaws would 
be allowed to remain in service because paragraph IWB-3132.3, via 
paragraph IWB-3643, allows a flaw up to 75 percent through-wall to 
remain in service. The NRC finds that larger flaws could grow to an 
unacceptable size between inspections, reducing structural margin and 
potentially challenging the structural integrity of safety-related 
Class 1 and Class 2 piping.
    Paragraph C-3112(a)(3) of Code Case N-813, provides the same 
alternatives for Class 2 piping as that of Paragraph B-3112(a)(3). The 
NRC has the same concerns for Class 2 piping as for Class 1 piping.
    Therefore, for the acceptance of preservice flaws by analytical 
evaluation, the NRC is adding a condition that prohibits the use of 
IWB-3112(a)(3) and IWC-3112(a)(3) in the 2013 Edition of ASME BPV Code 
Section XI through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(ii) of Sec.  50.55a.
10 CFR 50.55a(b)(2)(xlii) Section XI Condition: Steam Generator Nozzle-
to-Component Welds and Reactor Vessel Nozzle-to-Component Welds
    The NRC is adding Sec.  50.55a(b)(2)(xlii) to require that the 
examination of steam generator nozzle-to-component welds and reactor 
vessel nozzle-to-component welds must be a full volume examination and 
that the ultrasonic examination procedures, equipment, and personnel 
must be qualified by performance demonstration in accordance with 
Mandatory Appendix VIII of ASME Code, Section XI. These conditions are 
consistent with the conditions on ASME Code Case N-799 in Revision 19 
of RG 1.147.\4\
---------------------------------------------------------------------------

    \4\ The NRC notes that one condition, requiring the examination 
volume to include 100 percent of the weld, was not reflected in RG 
1.147 Revision 18, that accompanied that rule. That condition was 
developed in response to a public comment as described in the 
Federal Register notice for the rule, but the associated regulatory 
guide was not revised as intended due to an administrative error. 
The NRC has corrected that error in RG 1.147 Revision 19.
---------------------------------------------------------------------------

    This code case was developed for new construction of recent reactor 
designs to provide examination requirements for weld configurations 
(i.e., component-to-component welds). Specifically, the examination 
requirements described in Code Case N-799 apply to the weld 
configurations for the steam generator nozzle-to-reactor coolant pump 
casing weld in the AP1000 design and the reactor vessel-to-
recirculation pump weld in the Advanced Boiling Water Reactor design. 
These weld configurations and the associated examination requirements 
did not exist in Section XI and have now been incorporated into ASME 
Code, Section XI, IWB-2500. The NRC is authorizing the use of these 
examination requirements incorporated into Section XI, IWB-2500, with 
similar conditions to those on the use of Code Case N-799. The NRC is 
simplifying the conditions in Revision 19 of RG 1.147 by combining them 
and also relaxing the condition concerning removing or repairing 
defects that are examined by procedures qualified to detect or depth 
size defects.
    The first simplified condition in this rule combines the part of 
the first condition from Revision 19 of RG 1.147 concerning 
qualification with the second and third conditions, which also 
addresses qualification. This consolidation of the conditions from 
Revision 19 of RG 1.147 simplifies the qualification requirements by 
reducing the length and number of conditions.
    The second simplified condition in this rule combines part of the 
first condition from Revision 19 of RG 1.147 concerning full volume 
examination with the fourth condition, which requires flaws (cracks) 
detected but not sized to the requirements of ASME Code, Section XI, 
Appendix VIII be repaired or removed. This simplified second condition 
relaxes the conditions from Revision 19 of RG 1.147 by allowing 
acceptance of flaws based on a flaw evaluation for the portion of the 
weld volume that is not examined by a qualified ultrasonic examination 
in accordance with ASME Code, Section XI, Appendix VIII.
    The NRC recognizes that factors exist that may limit the ultrasonic 
examination volume that can be qualified by performance demonstration. 
For example, the qualified volume would be limited in components with 
wall thicknesses beyond the crack detection and sizing capabilities of 
a through wall ultrasonic performance-based qualification. To address 
the scenario in which the examination volume that can be qualified by 
performance demonstration is less than 100 percent of the volume, the 
NRC is allowing an ultrasonic examination of the qualified volume, 
provided that a flaw evaluation is performed to demonstrate the 
integrity of the examination volume that cannot be qualified by 
performance demonstration. The flaw evaluation should be of the largest 
hypothetical crack that could exist in the volume not qualified for 
ultrasonic examination. The licensee's revised examination plan is 
subject to prior NRC approval as an alternative in accordance with 
Sec.  50.55a(z). The NRC determines that this relaxed condition 
provides assurance that the integrity of the welds in question will be 
maintained, despite a limited examination capability.
    Therefore, in order to ensure that the examinations of steam 
generator nozzle-to-component welds and reactor vessel nozzle-to-
component welds will be examinations of the full volume of the welds 
and that the ultrasonic examination procedures, equipment, and 
personnel are qualified by performance demonstration, in accordance 
with Mandatory Appendix VIII of ASME Code, Section XI, the NRC is 
adding conditions to the provisions of Table IWB-2500-1, Examination 
Category B-F, Pressure Retaining Dissimilar Metal Welds in Vessel 
Nozzles, Item B5.11 (Reactor Vessel, NPS 4 or Larger Nozzle-to-
Component Butt Welds) of the 2013 Edition through the latest edition 
and addenda incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a. The NRC is also adding similar conditions to the provision of 
Table IWB-2500-1, Item B5.71 (Steam Generator, NPS 4 or Larger Nozzle-
to-Component Butt Welds) of the 2011 Addenda through the latest edition 
and addenda incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a.
    The NRC edited this condition from the proposed rule for clarity. 
Section 50.55a(b)(2)(xlii) of this final rule reflects this change.

C. ASME OM Code

10 CFR 50.55a(b)(3) Conditions on ASME OM Code
    The new Appendix IV in the 2017 Edition of the ASME OM Code 
provides improved preservice testing (PST) and IST of active pneumatic-
operated valves (AOVs) within the scope of the ASME OM Code. Appendix 
IV specifies quarterly stroke-time testing of AOVs, where practicable. 
These are similar to the current requirements in Subsection

[[Page 26554]]

ISTC, ``Inservice Testing of Valves in Light-Water Reactor Nuclear 
Power Plants,'' of the ASME OM Code. In addition, Appendix IV specifies 
a preservice performance assessment test for AOVs with low safety 
significance, and initial and periodic performance assessment testing 
for AOVs with high safety significance on a sampling basis over a 
maximum 10-year interval.
    The ASME developed the improved PST and IST provisions for AOVs in 
Appendix IV to the ASME OM Code in response to lessons learned from 
operating experience and test programs for AOVs and other power-
operated valves (POVs) used at nuclear power plants. Over the years, 
the NRC has issued numerous generic communications to address 
weaknesses with AOVs and other POVs in performing their safety 
functions. For example, the NRC issued Generic Letter (GL) 88-14, 
``Instrument Air Supply System Problems Affecting Safety-Related 
Equipment,'' to request that licensees verify that AOVs will perform as 
expected in accordance with all design-basis events. The NRC provided 
the results of studies of POV issues in several documents, including 
NUREG/CR-6654, ``A Study of Air-Operated Valves in U.S. Nuclear Power 
Plants'' (ADAMS Accession No. ML003691872). The NRC has issued several 
information notices to alert licensees to IST experience related to POV 
performance, including IN 86-50, ``Inadequate Testing to Detect 
Failures of Safety-Related Pneumatic Components or Systems;'' and IN 
85-84, ``Inadequate Inservice Testing of Main Steam Isolation Valves.'' 
The NRC issued IN 96-48, ``Motor-Operated Valve Performance Issues,'' 
which described lessons learned from motor-operated valve (MOV) 
programs that are applicable to other POVs. Based on operating 
experience with the capability of POVs to perform their safety 
functions, the NRC established Generic Safety Issue 158, ``Performance 
of Safety-Related Power-Operated Valves Under Design-Basis 
Conditions,'' to evaluate whether additional regulatory actions were 
necessary to address POV performance issues. In Regulatory Issue 
Summary 2000-03, ``Resolution of Generic Safety Issue (GSI) 158, 
`Performance of Safety Related Power-Operated Valves Under Design-Basis 
Conditions','' dated March 15, 2000, the NRC closed GSI-158 by 
specifying attributes for an effective POV testing program that 
incorporates lessons learned from MOV research and testing programs. 
More recently, the NRC issued IN 2015-13, ``Main Steam Isolation Valve 
Failure Events,'' to alert nuclear power plant applicants and licensees 
to examples of operating experience where deficiencies in licensee 
processes and procedures can contribute to the failure of main steam 
isolation valves (MSIVs), which may be operated by air actuators or 
combined air/hydraulic actuators. The NRC considers that the improved 
IST provisions specified in Appendix IV to the ASME OM Code will 
address the POV performance issues identified by operating experience 
with AOVs, including MSIVs, at nuclear power plants.
    Paragraph IV-3800, ``Risk-Informed AOV Inservice Testing,'' allows 
the establishment of risk-informed AOV IST that incorporates risk 
insights in conjunction with functional margin to establish AOV 
grouping, acceptance criteria, exercising requirements, and testing 
intervals. Risk-informed AOV IST includes initial and periodic 
performance assessment testing of high safety significant AOVs with the 
results of that testing used to confirm the capability of low-safety 
significant AOVs within the same AOV group. For example, paragraph IV-
3600, ``Grouping of AOVs for Performance Assessment Testing,'' states 
that test results shall be evaluated for all AOVs in a group. Paragraph 
IV-6500, ``Performance Assessment Test Corrective Action,'' specifies 
that correction action be taken in accordance with the Owner's 
corrective action requirements if AOV performance is unacceptable. The 
NRC considers that these provisions in Appendix IV will provide 
assurance that all AOVs within the scope of Appendix IV will be 
assessed for their operational readiness initially and on a periodic 
basis. The NRC revised the last sentence of Sec.  50.55a(b)(3) to 
specify that when implementing the ASME OM Code, conditions are 
applicable only as specified in (b)(3).
10 CFR 50.55a(b)(3)(ii) OM Condition: Motor-Operated Valve (MOV) 
Testing
    The NRC is amending Sec.  50.55a(b)(3)(ii) to specify that the 
condition applies to the latest edition and addenda of the ASME OM Code 
incorporated by reference in Sec.  50.55a(a)(1)(iv). This allows future 
rulemakings to revise Sec.  50.55a(a)(1)(iv) to incorporate the latest 
edition of the ASME OM Code without the need to revise Sec.  
50.55a(b)(3)(ii).
10 CFR 50.55a(b)(3)(iv) OM Condition: Check Valves (Appendix II)
    The NRC is amending Sec.  50.55a(b)(3)(iv) to accept the use of 
Appendix II, ``Check Valve Condition Monitoring Program,'' in the 2017 
Edition of the ASME OM Code without conditions based on its updated 
provisions. For example, Appendix II in the 2017 Edition of the ASME OM 
Code incorporates Table II, ``Maximum Intervals for Use When Applying 
Interval Extensions,'' as well as other conditions currently specified 
in Sec.  50.55a(b)(3)(iv). The NRC is also revising Sec.  
50.55a(b)(3)(iv) to apply Table II to Appendix II of the ASME OM Code, 
2003 Addenda through the 2015 Edition. Further, the NRC is removing the 
outdated conditions in paragraphs (b)(3)(iv)(A) through (D) based on 
their application to older editions and addenda of the ASME OM Code 
that are no longer applied at nuclear power plants, and on the 
incorporation of those conditions in recent editions and addenda of the 
ASME OM Code.
10 CFR 50.55a(b)(3)(viii) OM Condition: Subsection ISTE
    The NRC is amending Sec.  50.55a(b)(3)(viii) to specify that the 
condition on the use of Subsection ISTE, ``Risk-Informed Inservice 
Testing of Components in Light-Water Reactor Nuclear Power Plants,'' 
applies to the latest edition and addenda of the ASME OM Code 
incorporated by reference in Sec.  50.55a(a)(1)(iv). This allows future 
rulemakings to revise Sec.  50.55a(a)(1)(iv) to incorporate the latest 
edition of the ASME OM Code without the need to revise Sec.  
50.55a(b)(3)(viii).
10 CFR 50.55a(b)(3)(ix) OM Condition: Subsection ISTF
    The NRC is amending Sec.  50.55a(b)(3)(ix) to specify that 
Subsection ISTF, ``Inservice Testing of Pumps in Water-Cooled Reactor 
Nuclear Power Plants--Post-2000 Plants,'' of the ASME OM Code, 2017 
Edition, is acceptable without conditions. The NRC is also amending 
Sec.  50.55a(b)(3)(ix) to specify that licensees applying Subsection 
ISTF in the 2015 Edition of the ASME OM Code shall satisfy the 
requirements of Mandatory Appendix V, ``Pump Periodic Verification Test 
Program,'' of the ASME OM Code, in addition to the current requirement 
to satisfy Appendix V when applying Subsection ISTF in the 2012 Edition 
of the ASME OM Code. Subsection ISTF in the 2017 Edition of the ASME OM 
Code has incorporated the provisions from Appendix V such that this 
condition is not necessary for the 2017 Edition of the ASME OM Code.
10 CFR 50.55a(b)(3)(xi) OM Condition: Valve Position Indication
    The NRC is amending Sec.  50.55a(b)(3)(xi) for the implementation

[[Page 26555]]

of paragraph ISTC-3700, ``Position Verification Testing,'' in the ASME 
OM Code to apply to the 2012 Edition through the latest edition and 
addenda of the ASME OM Code incorporated by reference in Sec.  
50.55a(a)(1)(iv). This allows future rulemakings to revise Sec.  
50.55a(a)(1)(iv) to incorporate the latest edition and addenda of the 
ASME OM Code without the need to revise Sec.  50.55a(b)(3)(xi). In 
addition, the NRC is clarifying this condition to apply to all valves 
with remote position indicators within the scope of Subsection ISTC, 
``Inservice Testing of Valves in Water-Cooled Reactor Nuclear Power 
Plants,'' including MOVs within the scope of Mandatory Appendix III, 
``Preservice and Inservice Testing Active Electric Motor-Operated Valve 
Assemblies in Water-Cooled Reactor Nuclear Power Plants.'' ISTC-3700 
references Mandatory Appendix III for valve position testing of MOVs. 
The development of Mandatory Appendix III was intended to verify valve 
position indication as part of the diagnostic testing (rather than 
exercising) performed at the intervals established by the appendix.
    In response to public comments, the NRC is clarifying Sec.  
50.55a(b)(3)(xi) to refer to Subsection ISTC including its mandatory 
appendices and their verification methods and frequencies. This 
clarification will ensure that verification of valve position 
indication is understood to apply to all valves with remote position 
indication addressed in Subsection ISTC and all of its mandatory 
appendices. The NRC notes that licensees may request an NRC authorized 
alternative to this condition under 10 CFR 50.55a(z).
10 CFR 50.55a(f): Preservice and Inservice Testing Requirements
    The NRC regulations in Sec.  50.55a(f) specify that systems and 
components of boiling and pressurized water-cooled nuclear power 
reactors must meet the requirements for preservice and inservice 
testing of the ASME BPV Code and ASME OM Code. Paragraph (f) in Sec.  
50.55a states that the requirements for inservice inspection of Class 
1, Class 2, Class 3, Class MC, and Class CC components (including their 
supports) are located in paragraph (g) in Sec.  50.55a. Applicants and 
licensees should note that requirements for inservice examination and 
testing of dynamic restraints (snubbers) are located in paragraph 
(b)(3)(v) in Sec.  50.55a. The NRC is considering this clarification of 
the location of inservice examination and testing requirements for 
dynamic restraints in Sec.  50.55a(f) and (g) for a future rulemaking.
    A stakeholder submitted a public comment recommending that the NRC 
add a statement that pressure relief devices requiring testing per 
Sec.  50.55a(f)(4) shall be limited to valves and rupture disks 
installed in piping systems designed to the ASME BPV Codes or ASME B31 
standards. The NRC agrees that the ASME OM Code applies to pumps, 
valves, and dynamic restraints (snubbers) in piping systems. For 
example, the ASME OM Code does not apply to blowout panels in 
structures. However, such a clarification was not included in the 
proposed rule, and the NRC does not see an immediate need to clarify 
the applicability of the ASME OM Code in this regard. The NRC 
understands that the ASME OM Code committee is preparing a 
clarification to the ASME OM Code to specify its application to piping 
systems. Therefore, the NRC will evaluate the need for clarification of 
ASME OM Code to piping systems in a future rulemaking.
10 CFR 50.55a(f)(4)(i): Applicable IST Code: Initial 120-Month Interval
    Several stakeholders submitted public comments on the Sec.  50.55a 
2009-2013 proposed rule requesting that the time schedule for complying 
with the latest ASME Code edition and addenda in Sec.  50.55a(f)(4)(i) 
and (g)(4)(i) for the IST and ISI programs, respectively, be relaxed 
from the current time interval of 12 months to a new time interval of 
24 months prior to the applicable milestones in those paragraphs. The 
ASME reiterated this request during an NRC/ASME management public 
teleconference that was held on March 16, 2016. During that 
teleconference, ASME discussed the challenges associated with meeting 
the 12-month time schedule in order to submit timely relief or 
alternative requests for NRC review. These comments were outside the 
scope of the proposed Sec.  50.55a ASME 2009-2013 rule. However, the 
NRC indicated that the request would be considered in a future 
rulemaking.
    In evaluating the suggested change, the NRC determined that the 
primary benefit from the relaxation of this Sec.  50.55a(f)(4)(i) 
requirement is that licensees of new nuclear power plants will have 
more time to prepare their initial IST program and procedures and any 
proposed relief or alternative requests to the applicable edition of 
the ASME OM Code. The NRC determined that relaxation of the time 
schedule for satisfying the latest edition of the ASME OM Code for the 
initial 120-month IST interval is appropriate. However, the NRC 
considered that a 24-month time schedule would be contrary to the 
intent of the requirement to apply the latest edition of the ASME OM 
Code that is published every 24 months because it could result in 
licensees applying an outdated edition in the initial 120-month IST 
interval. Therefore, the NRC is extending the time schedule to satisfy 
the latest edition and addenda of the ASME OM Code from the current 12 
months to 18 months for the initial 120-month IST interval.
10 CFR 50.55a(f)(4)(ii): Applicable IST Code: Successive 120-Month 
Intervals
    As discussed in the previous section, several stakeholders 
submitted public comments on the Sec.  50.55a 2009-2013 proposed rule, 
requesting that the time schedule for complying with the latest ASME 
Code edition in Sec.  50.55a(f)(4)(ii) and (g)(4)(ii) for the IST and 
ISI programs, respectively, be relaxed from the current time period of 
12 months to a new time period of 24 months prior to the applicable 
milestones in those paragraphs. The ASME reiterated this request during 
an NRC/ASME management public teleconference that was held on March 16, 
2016. During that teleconference, ASME discussed the challenges 
associated with meeting the 12-month time schedule in order to submit 
timely relief or alternative requests for NRC review. These comments 
were outside the scope of the proposed Sec.  50.55a ASME 2009-2013 
rule. However, the NRC staff indicated that the proposed change would 
be considered for a future rulemaking. The NRC determined that the 
primary benefit from the relaxation of this Sec.  50.55a(f)(4)(ii) 
requirement is that licensees of nuclear power plants will have more 
time to update their successive IST programs and procedures, and to 
prepare any proposed relief or alternative requests to the applicable 
edition of the ASME OM Code. In addition, licensees of each nuclear 
power plant will not need to review ASME OM Code editions incorporated 
by reference in Sec.  50.55a after the relaxed 18-month time period 
before the start of the IST program interval compared to the 12-month 
time period required by the current regulations. The NRC determined 
that relaxation of the time schedule for satisfying the latest edition 
of the ASME OM Code for the successive 120-month IST interval is 
appropriate. However, the NRC considered that a 24-month time schedule 
would be contrary to the intent of the requirement to apply the latest 
edition of the ASME OM Code that is published every 24 months. 
Therefore, the NRC is extending the time schedule to satisfy the latest 
edition and addenda of the ASME OM

[[Page 26556]]

Code from the current 12 months to 18 months for successive 120-month 
IST intervals.
10 CFR 50.55a(f)(7) Inservice Testing Reporting Requirements
    The NRC proposed adding Sec.  50.55a(f)(7) to require nuclear power 
plant applicants and licensees to submit their IST Plans and interim 
IST Plan updates related to pumps and valves, and IST Plans and interim 
Plan updates related to snubber examination and testing to NRC 
Headquarters.
    The ASME OM Code states in paragraph (a) of ISTA-3200, 
``Administrative Requirements,'' that IST Plans shall be filed with the 
regulatory authorities having jurisdiction at the plant site. The NRC 
needs these IST Plans for use in evaluating relief and alternative 
requests, and deferral of quarterly testing to cold shutdowns and 
refueling outages. However, the ASME is planning to remove this 
provision from the ASME OM Code in a future edition because this 
provision is more appropriate as a regulatory requirement rather than a 
Code requirement. This change was proposed rather than in a future 
rulemaking to ensure that there will not be a period of time when this 
requirement is not in effect. Therefore, the condition would be an 
administrative change that would relocate the provision from the ASME 
OM Code to Sec.  50.55a. However, in response to public comments 
discussed below, the NRC removed Sec.  50.55a(f)(7) in this final rule. 
The NRC will reconsider this condition if the requirement is removed 
from a future Edition of the ASME OM Code.
10 CFR 50.55a(g)(4)(i): Applicable ISI Code: Initial 120-Month Interval
    The NRC is amending Sec.  50.55a(g)(4)(i) to relax the time 
schedule for complying with the latest edition of the ASME BPV Code for 
the initial 120-month ISI program interval, respectively, from 12 
months to 18 months. The basis for the relaxation of the time schedule 
discussed previously for the requirement in Sec.  50.55a(f)(4)(i) to 
comply with the latest edition and addenda of ASME BPV Code, Section 
XI, for the initial 120-month ISI program is also applicable to the 
relaxation of the time period for complying with the latest edition and 
addenda of the ASME BPV Code for the initial 120-month ISI program.
10 CFR 50.55a(g)(4)(ii): Applicable ISI Code: Successive 120-Month 
Intervals
    The NRC is amending Sec.  50.55a(g)(4)(ii) to relax the time 
schedule for complying with the latest edition and addenda of the ASME 
BPV Code for the successive 120-month ISI program intervals, 
respectively, from 12 months to 18 months. The basis for the relaxation 
of the time schedule discussed above for the requirement in Sec.  
50.55a(f)(4)(ii) to comply with the latest edition and addenda of the 
ASME BPV Code, Section XI, for the successive 120-month ISI programs is 
also applicable to the relaxation of the time period for complying with 
the latest edition and addenda of the ASME BPV Code for the successive 
120-month ISI programs. The NRC is amending the regulation in Sec.  
50.55a(g)(4)(ii) to provide up to an 18-month period for licensees to 
update their Appendix VIII program for those licensees whose ISI 
interval commences during the 12 through 18-month period after June 3, 
2020.
10 CFR 50.55a(g)(6)(ii)(C): Augmented ISI Requirements: Implementation 
of Appendix VIII to Section XI
    The NRC is removing the language found in Sec.  50.55a(g)(6)(ii)(C) 
from the current regulations. This paragraph describes requirements for 
initial implementation of older supplements in ASME BPV Code, Section 
XI Appendix VIII. Because the implementation dates have passed, and 
because licensees are no longer using these older editions and addenda 
of the Code that are referenced in this paragraph, the NRC is removing 
the condition.

D. ASME Code Cases

ASME BPV Code Case N-729-6
    On September 10, 2008, the NRC issued a final rule to update Sec.  
50.55a to incorporate by reference the 2004 Edition of the ASME BPV 
Code (73 FR 52730). As part of the final rule, Sec.  
50.55a(g)(6)(ii)(D) implemented an augmented inservice inspection 
program for the examination of RPV upper head penetration nozzles and 
associated partial penetration welds. The program required the 
implementation of ASME BPV Code Case N-729-1, with certain conditions.
    The application of ASME BPV Code Case N-729-1 was necessary because 
the inspections required by the 2004 Edition of the ASME BPV Code, 
Section XI were not written to address degradation caused by primary 
water stress corrosion cracking (PWSCC) of the RPV upper head 
penetration nozzles and associated welds. The safety consequences of 
inadequate inspections of the subject nozzles can be significant. The 
NRC's determination that the ASME BPV Code-required inspections are 
inadequate is based upon operating experience and analysis, because 
nickel-based Alloy 600/82/182 materials in the RPV head penetration 
nozzles and associated welds are susceptible to PWSCC. The absence of 
an effective inspection regime could, over time, result in unacceptable 
circumferential cracking, or the degradation of the RPV upper head or 
other reactor coolant system components by leakage-assisted corrosion. 
These degradation mechanisms increase the probability of a loss-of-
coolant accident.
    Examination frequencies and methods for RPV upper head penetration 
nozzles and welds are provided in ASME BPV Code Case N-729-1. The use 
of code cases is voluntary, so these provisions were developed, in 
part, with the expectation that the NRC would incorporate the code case 
by reference into Sec.  50.55a. Therefore, the NRC adopted rule 
language in Sec.  50.55a(g)(6)(ii)(D), requiring implementation of ASME 
BPV Code Case N-729-1, with conditions, in order to enhance the 
examination requirements in the ASME BPV Code, Section XI for RPV upper 
head penetration nozzles and welds. The examinations conducted in 
accordance with ASME BPV Code Case N-729-1 were intended to provide 
reasonable assurance that ASME BPV Code allowable limits will not be 
exceeded and that PWSCC will not lead to failure of the RPV upper head 
penetration nozzles or welds. However, the NRC concluded that certain 
conditions were needed in implementing the examinations in ASME BPV 
Code Case N-729-1. These conditions are set forth in Sec.  
50.55a(g)(6)(ii)(D).
    On March 3, 2016, the ASME approved the sixth revision of ASME BPV 
Code Case N-729 (N-729-6). This revision changed certain requirements 
based on a consensus review of the inspection techniques and 
frequencies. These changes were deemed necessary by the ASME to 
supersede the previous requirements under previous versions of N-729 to 
establish an effective long-term inspection program for the RPV upper 
head penetration nozzles and associated welds in PWRs. The major 
changes in the latest revisions are the inclusion of peening mitigation 
and extending the replaced head volumetric inspection frequency. Other 
minor changes were also made to address editorial issues and to clarify 
the code case requirements.
    The NRC is updating the requirements of Sec.  50.55a(g)(6)(ii)(D) 
to require licensees of PWRs to implement ASME BPV Code Case N-729-6, 
with certain conditions. The NRC conditions have been modified to 
address the changes in

[[Page 26557]]

ASME BPV Code Case N-729-6 from the latest NRC-approved ASME Code Case 
N-729 revision in Sec.  50.55a(g)(6)(ii)(D), revision 4, (N-729-4). The 
NRC's revisions to the conditions on ASME BPV Code Case N-729-4 that 
support the implementation of N-729-6 are discussed in the next 
sections.
10 CFR 50.55a(g)(6)(ii)(D) Augmented ISI Requirements: Reactor Vessel 
Head Inspections
    The NRC is revising the paragraphs in Sec.  50.55a(g)(6)(ii)(D) as 
summarized in the following discussions, which identify the changes in 
requirements associated with the update from ASME BPV Code Case N-729-4 
to N-729-6. The major changes in the code case revision allow peening 
as a mitigation method and extend the PWSCC-resistant RPV upper head 
inspection frequency from 10 years to 20 years. Additionally, the code 
case revision allowed the use of the similarities in sister plants to 
extend inspection intervals. The NRC is not able to fully endorse this 
item; therefore, the NRC is adding a new condition. The NRC has 
determined that one previous condition restricting the use of Appendix 
I of the code case could be relaxed. Further, the code case deadline 
for baseline examinations of February 10, 2008 is well in the past, 
therefore the NRC is adding a condition that ensures new plants can 
perform baseline examinations without the need for an alternative to 
these requirements under Sec.  50.55a(z). Finally, the NRC is adding a 
condition that allows licensees to use a volumetric leak path 
assessment in lieu of a surface examination.
10 CFR 50.55a(g)(6)(ii)(D)(1) Implementation
    The NRC is revising Sec.  50.55a(g)(6)(ii)(D)(1) to change the 
version of ASME BPV Code Case N-729 from N-729-4 to N-729-6 for the 
reasons previously set forth. Due to the incorporation of N-729-6, the 
date to establish applicability for licensed PWRs will be changed to 
anytime within one year of June 3, 2020. The delay in implementing N-
729-6 is provided to allow some flexibility for licensees to implement 
the requirements. No new inspections are required; therefore, this 
allows licensees to phase in the new program consistent with their 
needs and outage schedules. The NRC is also including wording to allow 
licensee's previous NRC-approved alternatives to remain valid 
regardless of the version of ASME BPV Code Case N-729-6 they were 
written against. The NRC has reviewed all currently applicable licensee 
alternatives to this code case and has found that the change from Code 
Case N-729-4 to N-729-6 required by this regulation neither invalidates 
nor degrades plant safety associated with the continued use of existing 
alternatives. Therefore, to provide regulatory efficiency, the NRC 
finds that all previous NRC-approved alternatives will remain valid for 
their specifically NRC-approved duration of applicability.
10 CFR 50.55a(g)(6)(ii)(D)(2) Appendix I Use
    The NRC is revising Sec.  50.55a(g)(6)(ii)(D)(2). The NRC has 
determined that the current condition, that the use of Appendix I is 
not permitted, is no longer necessary. However, the NRC is adding a new 
condition that the analyses required by the code case for missed 
coverage both above and below the J-groove weld include the analysis 
described in I-3000. The NRC's basis for revising the condition is 
that, based on its reviews of alternatives proposed by licensees 
related to this issue, over a period in excess of 10 years, it has 
become apparent to the NRC that the I-3000 method produces satisfactory 
results and is correctly performed by licensees. The NRC notes that the 
other options available in Appendix I have not been used by the NRC as 
a basis for relief during this period, including the probabilistic 
approach which has not been proposed by licensees and therefore does 
not have a history of being evaluated (including the acceptance 
criteria) by the NRC.
    The NRC finds the change to the condition will have minimal impact 
on safety, while minimizing the regulatory burden of NRC review and 
approval of a standardized method to provide reasonable assurance of 
structural integrity of a reduced inspection area.
10 CFR 50.55a(g)(6)(ii)(D)(4) Surface Exam Acceptance Criteria
    The NRC is revising Sec.  50.55a(g)(6)(ii)(D), the current 
condition on surface examination acceptance criteria, to update the 
ASME BPV Code Case reference. The NRC is modifying the condition Sec.  
50.55a(g)(6)(ii)(D)(4) by changing the referenced version of the 
applicable ASME BPV Code Case N-729 from N-729-4 to N-729-6.
10 CFR 50.55a(g)(6)(ii)(D)(5) Peening
    The NRC is adding a new condition that will allow licensees to 
obtain examination relief for peening of their RPV upper heads in 
accordance with the latest NRC-approved requirements, contained in 
Electric Power Research Institute (EPRI) Topical Report, ``Materials 
Reliability Program: Topical Report for Primary Water Stress Corrosion 
Cracking Mitigation by Surface Stress Improvement,'' (MRP-335, Revision 
3-A) (ADAMS Accession No. ML16319A282). This document provides 
guidelines for the NRC-approved performance criteria, qualification 
requirements, inspection frequency, and scope. A licensee may peen any 
component in accordance with the requirements and limitations of the 
ASME Code. However, in order to obtain NRC-approved examination relief 
for an RPV head mitigated with peening, as described in MRP-335, 
Revision 3-A, this condition establishes MRP-335, Revision 3-A as the 
requirement for performance criteria, qualifications and inspections. 
Otherwise the requirements of an unmitigated RPV upper head inspection 
program shall apply.
    As part of this condition, the NRC is removing two of the 
requirements contained in MRP-335, Revision 3-A: (1) The submission of 
a plant-specific alternative to the code case will not be required; and 
(2) Condition 5.4 will not be required.
    Hence, the NRC's condition combines the use of the latest NRC-
accepted performance criteria, qualification and inspection 
requirements in MRP-335, Revision 3-A, would allow licensees to not 
have to submit a plant-specific proposed alternative to adopt the 
inspection frequency of peened RPV head penetration nozzles in MRP-335, 
Revision 3-A, and does not require licensees to adhere to NRC Condition 
5.4 of MRP-335, Revision 3-A. By combining these points in the 
condition, it alleviates the need to highlight nine areas in N-729-6 
that do not conform to the current NRC-approved requirements for 
inspection relief provided in MRP-335, Revision 3-A.
    Because the NRC references MRP-335, Revision 3-A, within this 
condition on the requirements in the ASME Code Case, the NRC is 
incorporating by reference MRP-335, Revision 3-A, into Sec.  
50.55a(a)(4)(i).
10 CFR 50.55a(g)(6)(ii)(D)(6) Baseline Examinations
    The NRC is adding a new condition to address baseline examinations. 
Note 7(c) of Table 1 of ASME BPV Code Case N-729-6 requires baseline 
volumetric and surface examinations for plants with an RPV upper head 
with less than 8 effective degradation years (EDY) by no later than 
February 10, 2008. This requirement has been in place since ASME BPV 
Code Case N-729-1 was first required by this section, and it was a 
carryover requirement from the First

[[Page 26558]]

Revised NRC Order EA-03-009. However, since any new RPV upper head 
replacements would occur after 2008, this requirement can no longer be 
met. While it is not expected that a new head using A600 nozzles would 
be installed, the NRC is conditioning this section to prevent the need 
for a licensee to submit a proposed alternative for such an event, 
should it occur. The NRC condition requires a licensee to perform a 
baseline volumetric and surface examination within 2.25 reinspection 
years not to exceed 8 calendar years, as required under N-729-6, Table 
1.
10 CFR 50.55a(g)(6)(ii)(D)(7) Sister Plants
    The NRC is adding a new condition to address the use of the term 
sister plants for the examinations of RPV upper heads. The use of 
``sister plants'' under ASME BPV Code Case N-729-6 would allow 
extension of the volumetric inspection of replaced RPV heads with 
resistant materials from the current 10-year inspection frequency to a 
period of up to 40 years.
    As part of mandating the use of ASME BPV Code Case N-729-6 in this 
final rule, the NRC is approving the ASME Code's extension of the 
volumetric inspection frequency from every 10 years to every 20 years. 
The NRC finds that the documents, ``Technical Basis for Reexamination 
Interval Extension for Alloy 690 PWR Reactor Vessel Top Head 
Penetration Nozzles (MRP-375)'' and improvement factors ``Recommended 
Factors of Improvement for Evaluating Primary Water Stress Corrosion 
Cracking (PWSCC) Growth Rates of Thick-Wall Alloy 690 Materials and 
Alloy 52, 152, and Variants Welds (MRP-386),'' provide a sound basis 
for a 20-year volumetric inspection interval and a 5-year bare metal 
visual inspection interval for Alloy 690/52/152 materials subject to 
this code case thereby providing reasonable assurance of the structural 
integrity of the RPV heads.
    However, in this final rule, the NRC is adding a condition to 
prohibit the concept of ``sister plants''. If used, this concept would 
increase the inspection interval for plants with sisters from 20 years 
to 40 years. The NRC is currently evaluating both the definition of 
sister plants and factors of improvement between the growth of PWSCC in 
Alloy 600/82/182 and Alloy 690/52/152.
    It is unclear to the NRC whether the criteria for sister plants 
(i.e., same owner) are appropriate criteria. The NRC also questions 
whether other criteria such as environment, alloy heat, and numbers of 
sister plants in a particular group should be included in the 
definition.
    The NRC continues to review information on PWSCC growth rates and 
factors of improvement for Alloy 690/52/152 and Alloy 600/82/182 as 
proposed in MRP-386. While the NRC has concluded that crack growth in 
Alloy 690/52/152 is sufficiently slower than in Alloy 600/82/182 to 
support an inspection interval of 20 years, work continues in assessing 
whether the data and analyses support a 40-year interval.
    Public comments concerning both the definition of sister plants and 
crack growth rate factors of improvement were solicited during the 
comment period for the proposed rule. The NRC did not receive any 
comments on these topics.
10 CFR 50.55a(g)(6)(ii)(D)(8) Volumetric Leak Path
    The NRC is adding a new condition to substitute a volumetric leak 
path assessment for the required surface exam of the partial 
penetration weld of Paragraph -3200(b). The NRC finds that the use of a 
volumetric leak path assessment is more useful to confirm a possible 
leakage condition through the J-groove weld than a surface examination 
of the J-groove weld. While a surface examination may detect surface 
cracking, it will not confirm that such an indication is a flaw that 
caused leakage. A positive volumetric leak path assessment will provide 
a clear confirmation of leakage, either through the nozzle, weld or 
both. The NRC notes, that since all nozzles have had a volumetric 
examination, a baseline volumetric leak path assessment is available 
for comparison, and therefore provides additional assurance of 
effectiveness of the volumetric leak path assessment technique. As 
such, to eliminate the need for potential proposed alternatives 
requiring NRC review and authorization, this condition is being added 
to increase regulatory efficiency.
ASME BPV Code Case N-770-5
    On June 21, 2011 (76 FR 36232), the NRC issued a final rule 
including Sec.  50.55a(g)(6)(ii)(F), requiring the implementation of 
ASME BPV Code Case N-770-1, ``Alternative Examination Requirements and 
Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt 
Welds Fabricated with UNS N06082 or UNS N86182 Weld Filler Material 
With or Without Application of Listed Mitigation Activities,'' with 
certain conditions. On November 7, 2016, the ASME approved the fifth 
revision of ASME BPV Code Case N-770 (N-770-5). The major changes from 
N-770-2, the last revision to be mandated by Sec.  50.55a(g)(6)(ii)(F), 
to N-770-5 included extending the inspection frequency for cold leg 
temperature dissimilar metal butt welds greater than 14-inches in 
diameter to once per inspection interval not to exceed 13 years, 
performance criteria and inspections for peening mitigated welds, and 
inservice inspection requirements for excavate and weld repair 
mitigations. Minor changes were also made to address editorial issues, 
to correct figures, or to add clarity. The NRC finds that the updates 
and improvements in N-770-5 are sufficient to update Sec.  
50.55a(g)(6)(ii)(F).
    The NRC, therefore, is revising the requirements of Sec.  
50.55a(g)(6)(ii)(F) to require licensees to implement ASME BPV Code 
Case N-770-5, with conditions. The previous NRC conditions have been 
modified to address the changes in ASME BPV Code Case N-770-5 and to 
ensure that this regulatory framework will provide adequate protection 
of public health and safety. The following sections discuss each of the 
NRC's revisions to the conditions on ASME BPV Code Case N-770-2 that 
support the implementation of N-770-5.
10 CFR 50.55a(g)(6)(ii)(F)(1) Augmented ISI Requirements: Examination 
Requirements for Class 1 Piping and Nozzle Dissimilar-Metal Butt 
Welds--(1) Implementation
    The NRC is revising this condition to mandate the use of ASME BPV 
Code Case N-770-5, as conditioned by this section, in lieu of the 
current requirement to mandate ASME BPV Code Case N-770-2. The wording 
of this condition allows a licensee to adopt this change anytime during 
one year of June 3, 2020. The delay in implementing N-770-5 is provided 
to allow some flexibility for licensees to implement the new 
requirements. Finally, included in this provision is an allowance for 
all previous NRC-approved licensee's alternatives to the requirements 
of this section to remain valid, regardless of the version of ASME BPV 
Code Case N-770 they were written against. The NRC has reviewed all 
currently applicable licensee alternatives to this code case and has 
found that the change from Code Case N-770-2 to N-770-5 required by 
this regulation neither invalidates nor degrades plant safety 
associated with the continued use of existing alternatives. Therefore, 
to provide regulatory efficiency, the NRC finds that all previous NRC-
approved alternatives will remain valid for their specifically NRC-
approved duration of applicability.

[[Page 26559]]

10 CFR 50.55a(g)(6)(ii)(F)(2) Categorization
    The NRC is revising this condition to include the categorization of 
welds mitigated by peening. This condition currently addresses the 
categorization for inspection of unmitigated welds and welds mitigated 
by various processes.
    The new section, to this revised condition, is to categorize 
dissimilar metal butt welds mitigated by peening. ``Topical Report for 
Primary Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement,'' MRP-335, is the technical basis summary document for the 
application of peening in upper heads and dissimilar metal butt welds 
to address primary water stress corrosion cracking. The NRC conducted a 
comprehensive review of this document for generic application. The 
requirements contained in the NRC-approved version of this report, MRP-
335, Revision 3-A differ in several respects from the requirements 
contained in ASME BPV Code Case N-770-5. As such, to avoid confusion 
with multiple conditions, the NRC is accepting categorization of welds 
as being mitigated by peening, if said peening follows the performance 
criteria, qualification requirements, and examination guidelines of 
MRP-335, Revision 3-A. Once implemented, the examination guidelines of 
MRP-335, Revision 3-A provide examination relief from the requirements 
of an unmitigated dissimilar metal butt weld. In addition, for the 
purposes of Sec.  50.55a(g)(6)(ii)(E)(1), peening of a dissimilar metal 
butt weld is considered a stress improvement technique.
    As part of this condition, the NRC is removing the need for the 
licensee to submit a plant-specific proposed alternative to implement 
the examination relief in accordance with MRP-335, Revision 3-A. 
Because MRP-335, Revision 3-A, is being used as a condition against the 
requirements in the ASME Code Case, the NRC is incorporating by 
reference MRP-335, Revision 3-A, into Sec.  50.55a(a)(4)(i).
    The requirements for categorization of all other mitigated or non-
mitigated welds remain the same.
    Except for the categorization of peening, this condition is 
technically the same as in the previous versions of this condition for 
mandated use of ASME BPV Code Cases N-770-2 and N-770-1.
10 CFR 50.55a(g)(6)(ii)(F)(3) Baseline Examinations
    The NRC is deleting this condition. The current condition regarding 
baseline inspections is considered unnecessary, as all baseline 
volumetric examinations have been completed. If a baseline examination 
is required, the licensee can follow the examination requirements in 
ASME BPV Code Case N-770-5. This condition number is reserved, to 
maintain the NRC condition numbering from the past rulemaking, and in 
this way, limit the need for additional updates to current procedures 
and documentation, when no substantive change has occurred.
10 CFR 50.55a(g)(6)(ii)(F)(4) Examination Coverage
    The NRC is revising this condition to make an editorial change to 
update the reference to ASME BPV Code Case N-770-2 to N-770-5.
10 CFR 50.55a(g)(6)(ii)(F)(6) Reporting Requirements
    The NRC is revising this condition to address the deletion of 
wording in Paragraph -3132.3(d) of ASME BPV Code Case N-770-5 and relax 
the requirement for submitting the summary report to the NRC. The 
purpose of this condition is to obtain timely notification of 
unanticipated flaw growth in a mitigated butt weld in the reactor 
coolant pressure boundary. While NRC onsite and regional inspectors 
provide a plant-specific role in assessing the current safe operation 
of a specific plant, the staff in the Office of Nuclear Reactor 
Regulation is also responsible for assessing the generic impact of the 
potential reduced effectiveness of a mitigation technique across the 
fleet. In order to address these concerns, the NRC has found that, in 
the event that a dissimilar metal butt weld is degraded, it is 
necessary for the NRC to obtain timely notification of the flaw growth 
and a report summarizing the evaluation, along with inputs, 
methodologies, assumptions, and causes of the new flaw or flaw growth 
within 30 days of the plant's return to service. This is a relaxation 
from the previous requirement to provide a report prior to entering 
mode 4 prior to plant startup. In its review of the prior condition, 
the NRC has determined that the burden associated with the submission 
of a report prior to entry into mode 4 exceeded the immediate safety 
benefit from the report. The NRC also has determined that a timely 
notification regarding the event was sufficient to begin the 
determination of whether an immediate generic safety concern exists. 
Further, the NRC has found the submittal of a report within 30 days is 
both necessary and sufficient to allow for the evaluation of any long-
term impacts of the flaw growth on the overall inspection programs for 
that specific mitigation type.
    The NRC has determined that the deletion of the following sentence 
from Paragraph -3132.3(d), ``Any indication in the weld overlay 
material characterized as stress corrosion cracking is unacceptable,'' 
did not have a sufficiently identified technical basis to support its 
removal. Given that the NRC's approval of weld overlays is based on the 
resistance of the overlay material to cracking, any flaw growth into 
this material should call into question the effectiveness of that 
specific mitigation method. However, the NRC recognizes that there 
could be instances were NDE measurement uncertainty may require a 
conservative call on flaw size that may lead to the assumption of flaw 
growth. Rather than automatically assume this flaw growth is 
unacceptable, as stated in the previous requirement mandated under ASME 
BPV Code Case N-770-2, the NRC has found that reasonable assurance of 
plant safety could be assured by reporting this condition to the NRC 
for evaluation, in accordance with this condition. This relaxation of 
the previous requirement allows for regulatory flexibility in assessing 
the safety significance of any potential flaw growth.
10 CFR 50.55a(g)(6)(ii)(F)(9) Deferral
    The NRC is revising this condition to address the potential 
deferrals of volumetric inspections for welds mitigated by peening as 
well as for welds mitigated by the excavate and weld repair technique. 
Volumetric inspections performed once per interval or on a ten-year 
basis can, in some instances, be deferred to the end of the current 
ten-year inservice inspection interval. As such, this could allow an 
inspection frequency, which is assumed to be approximately 10 years to 
be extended to as much as 20 years. While there are certain conditions 
that would warrant such an extension, the NRC finds, in the following 
two instances, that allowing such deferrals would provide an 
unacceptable reduction in the margin for safety.
    For welds peened in accordance with the performance and 
qualification criteria of MRP-335, Revision 3-A, the long-term 
inservice inspection interval, as required by MRP-335, Revision 3-A 
Table 4-1, is once per inspection interval. Note 11 of Table 4-1 would 
allow deferral of peened welds beyond the 10-year inspection frequency. 
This deferral would be beyond the NRC technical basis of Paragraph 
4.6.3 in the NRC Safety Evaluation of MRP-335, Revision 3-A. Therefore, 
the NRC is

[[Page 26560]]

revising this condition to prohibit the deferral of examinations of 
peened welds, without the submission of a plant-specific proposed 
alternative for NRC review and approval.
    For welds mitigated with the excavate and weld repair technique, 
specifically inspection items M-2, N-1 and N-2, Note 11 of Table 1 of 
ASME BPV Code Case N-770-5 would allow the deferral of the second 
inservice examination to the end of the 10-year inservice inspection 
interval. The NRC finds the deferral of the second inservice exam 
unacceptable. If a weld was mitigated near the end of a 10-year 
inservice inspection interval, the first post mitigation examination 
might occur at the beginning of the next 10-year inservice inspection 
interval. Since the welds are required to be examined once per 
interval, the second post mitigation exam would be in the next 
interval. Because Note 11 allows the exams to be deferred, in such 
cases, it could approach twenty years between the first and second post 
mitigation exams. The NRC finds that a requirement to perform a second 
post mitigation exam within 10 years of the initial post mitigation 
exam to be more consistent with the reinspection timeline for other 
mitigations, such as full structural weld overlay and is therefore 
acceptable to the NRC. However, the NRC finds that, after the initial 
and second post mitigation examinations, provided the examination 
volumes show no indications of crack growth or new cracking, allowance 
for deferral of examination of these welds, as deemed appropriate, by 
the plant owner is acceptable. As such, this condition only restricts 
the deferral of the second inservice examination.
    Given the two new issues identified above, the NRC is revising 
Sec.  50.55a(g)(6)(ii)(F)(9) Deferral to prohibit the deferral of 
volumetric inspections of welds mitigated by peening under MRP-335, 
Revision 3-A and the first 10-year inservice inspection examination for 
welds mitigated by the excavate and weld repair technique, inspection 
items M-2, N-1 and N-2 only.
10 CFR 50.55a(g)(6)(ii)(F)(10) Examination Technique
    The NRC is revising this condition to make an editorial change to 
update the reference to ASME BPV Code Case N-770-2 to N-770-5.
10 CFR 50.55a(g)(6)(ii)(F)(11) Cast Stainless Steel
    The NRC is deleting this condition. The NRC recognized that the 
current condition in Sec.  50.55a was challenging to address within the 
current timeline. In the proposed rule, the NRC proposed an option for 
licensees to implement ASME Code Case N-824, a code case approved by 
ASME and incorporated into the 2013 Edition of the ASME Code, to 
perform the inspections through the cast stainless steel material. 
However, in response to a public comment on the proposed condition, and 
from information presented at NRC public meetings in January 2019, the 
NRC recognized that there is a limited number of welds that could 
achieve significant additional coverage from the proposed rule change. 
The NRC agrees that there would be limited improvement in safety and 
roughly the same number of proposed alternatives would be required. 
Therefore, there would be no improvement to regulatory efficiency. The 
NRC can continue to address the issue through a limited number of 
proposed alternatives until a new generic inspection qualification 
program can be effectively implemented. Accordingly, this final rule 
deletes this provision and reserves the section number to limit the 
need for additional updates to current procedures and documentation.
10 CFR 50.55a(g)(6)(ii)(F)(13) Encoded Ultrasonic Examination
    The NRC is revising this condition, which requires the encoded 
examination of unmitigated and mitigated cracked butt welds under the 
scope of ASME BPV Code Case N-770-2. The revision is being expanded to 
address changes in ASME BPV Code Case N-770-5 to include inspection 
categories B-1, B-2 for cold leg welds, which were previously under the 
single inspection category B, and the new inspection categories N-1, N-
2 and O for cracked welds mitigated with the excavate and weld repair 
technique. The inclusion of these weld categories is in line with the 
previous basis for this condition.
    Further, the NRC is relaxing the requirement for 100 percent of the 
required inspection volume to be examined with encoded techniques. The 
new requirement would allow essentially 100 percent of the required 
inspection volume to be examined with encoded techniques under the 
definition of essentially 100 percent in ASME BPV Code Case N-460. This 
code case allows the reduction to 90 percent coverage only if a 
physical limitation or impediment to full coverage is encountered 
during the inspection. The NRC finds this relaxation appropriate, given 
the potential that the physical size of the encoding equipment may 
reduce attainable coverage, when compared to manual techniques. The NRC 
finds that the reduction in safety associated with this potential minor 
decrease in coverage is minimal. Adoption of the revised condition will 
reduce unnecessary preparation and submittal of requests for NRC review 
and approval of alternatives to this requirement.
    The NRC edited this condition from the proposed rule for clarity. 
Section 50.55a(g)(6)(ii)(F)(13) of this final rule reflects this 
change.
10 CFR 50.55a(g)(6)(ii)(F)(14) Excavate and Weld Repair Cold Leg
    The NRC is adding a new condition to address the initial inspection 
of cold leg operating temperature welds after being mitigated by the 
excavate and weld repair technique. The excavate and weld repair 
technique is a new mitigation category introduced in ASME BPV Code Case 
N-770-5. The first inspection requirement for inspection item M-2, N-1 
and N-2 welds, after being mitigated, is during the 1st or 2nd 
refueling outages after mitigation. The NRC finds that the ASME BPV 
Code Case N-770-5 language does not provide separate inspection 
programs between the cold leg and the hot leg temperature for the first 
volumetric inspection. The NRC determines that, at hot leg 
temperatures, one fuel cycle is sufficient for a preexisting, 
nondetectable, crack to grow to detectable size (10 percent through 
wall). However, at cold leg temperatures, crack growth is sufficiently 
slow that preexisting, undetected, cracks are unlikely to reach 
detectable size in a single fuel cycle. Therefore, in order to ensure 
the effectiveness of the initial volumetric examination to verify no 
unanticipated flaw growth in the mitigated weld prior to extending the 
inspection frequency to 10 years or beyond, the NRC is adding a 
condition to require the first examination to be performed during the 
second refueling outage following the mitigation of cold leg operating 
temperature welds.
10 CFR 50.55a(g)(6)(ii)(F)(15) Cracked Excavate and Weld Repair
    The NRC is adding a new condition to address the long-term 
inspection frequency of cracked welds mitigated by the excavate and 
weld repair technique, i.e. inspection category N-1. The long-term 
volumetric inspection frequency for the cracked N-1 welds under ASME 
BPV Code Case N-770-5 is a 25 percent sample each 10-year inspection 
interval. In comparison, the NRC notes that the long-term volumetric 
inspection frequency of a non-cracked weld mitigated with the excavate 
and weld

[[Page 26561]]

repair technique without stress improvement (inspection category M-2) 
is 100 percent each 10-year inspection interval. Due to not attaining 
surface stress improvement, M-2 welds could potentially have cracking 
initiate at any time over the remaining life of the repair. Therefore, 
a volumetric inspection frequency of once per 10-year inspection 
frequency is warranted to verify weld structural integrity. However, 
every N-1 categorized weld already has a preexisting crack, but Code 
Case N-770-5 would allow a 25 percent sample inspection frequency each 
10-year inservice inspection interval. This could allow some N-1 welds 
with preexisting flaws to not be volumetrically inspected for the 
remainder of plant life. The NRC finds insufficient technical basis to 
support the difference in inspection frequency between N-1 and M-2 
welds. Therefore, the NRC is adding a condition on N-1 inspection 
category welds that requires the same long-term inspection frequency, 
as that determined acceptable by the ASME BPV Code Case N-770-5 for M-2 
welds, i.e., non-cracked 360 degree excavate and weld repair with no 
stress improvement credited.
10 CFR 50.55a(g)(6)(ii)(F)(16) Partial Arc Excavate and Weld Repair
    The NRC is adding a new condition to prevent the use of the 
inspection criteria for partial arc excavate and weld repair technique 
contained in ASME BPV Code Case N-770-5. The NRC staff notes that ASME 
BPV Code Case N-847 which describes the process of installing an 
excavate and weld repair has not been included in RG 1.147 and has not 
been incorporated by reference into Sec.  50.55a. As a result, 
licensees must propose an alternative to the ASME Code to make a repair 
using the excavate and weld repair technique. This prevention of the 
use of the inspection criteria contained in ASME BPV Code Case N-770-5, 
causes no additional burden on the licensee due to the requirement to 
propose an alternative to the ASME BPV Code to use the excavate and 
weld repair technique. The NRC's basis for this condition is that 
initial research into stress fields and crack growth associated with 
the ends of the repair indicated that the potential for crack growth 
rates to exceed those expected in the absence of the repair. The NRC 
also notes that there is potential for confusion regarding the 
inspection interval for these welds associated with whether Note 5 can 
be applied.

III. Public Outreach

    The NRC held a public meeting on July 30, 2018, to discuss several 
planned provisions that would be included in the upcoming publication 
of the proposed rule and to answer questions. The public meeting 
summary is available in ADAMS under Accession No. ML18219B862.
    The proposed rule was published on November 9, 2018, for a 75-day 
comment period (83 FR 56156). The public comment period closed on 
January 23, 2019.

IV. NRC Responses to Public Comments

    The NRC received 14 letters and emails in response to the 
opportunity for public comment on the proposed rule. These comment 
submissions were submitted by the following commenters (listed in order 
of receipt):

1. Private citizen, Jarno Makkonen
2. Private citizen, Ron Clow
3. Private citizen, J. E. O'Sullivan
4. Electric Power Research Institute (EPRI)
5. Private citizen, Glen Palmer
6. ASME
7. Private citizen, Richard Deopere
8. Private citizen, Edward Cavey
9. Private citizen, Adam Keyser
10. NuScale Power, LLC
11. Southern Nuclear Operating Company
12. Nuclear Energy Institute
13. Private Citizen, Mark Gowin
14. Exelon Generation Company, LLC

    In general, the comments:

     Suggested revising or rewording conditions to make them 
clearer.
     Opposed proposed conditions.
     Supplied additional information for NRC consideration.
     Supported incorporation of Code Cases N-729-6 and N-
770-5 into Sec.  50.55a.
     Asked questions or requested information from the NRC.
     Supported the proposed changes to add or remove 
conditions.
     Proposed rewriting or renumbering of paragraphs.
     Proposed removal of conditions related to older 
editions and addenda

    Due to the large number of comments received and the length of the 
NRC's response, a summary of the NRC's response to comments in areas of 
particular interest to stakeholders is included in this final rule. 
Special attention has been made to discuss comments that prompted the 
NRC to make more than editorial changes in this final rule from what 
the NRC had proposed. A discussion of all comments and complete NRC 
responses are presented in a separate document, ``Final Rule (10 CFR 
50.55a) American Society of Mechanical Engineers Codes and Code Cases: 
Analysis of Public Comments,'' (ADAMS Accession No. ML19095B549).

ASME BPV Code, Section III

10 CFR 50.55a(b)(1)(v) Section III Condition: Independence of 
Inspection
    A commenter was concerned that the wording in the proposed 
condition would prohibit the use of NCA-4134.10(a) in its entirety, and 
the condition should be clarified to apply only to the exception to 
paragraph 3.1 of Supplement 10S-1 of NQA-1-1994 Edition. The NRC agreed 
with the commenter's proposed revision to clarify the rule language. 
The intent of the rule modification is to limit the condition so that 
it applies only to the 1995 Edition through the 2009b Addenda of the 
2007 Edition. In response to this comment, the NRC revised Sec.  
50.55a(b)(1)(v) to state, ``Applicants or licensees may not apply the 
exception in NCA-4134.10(a) of Section III, 1995 Edition through 2009b 
Addenda of the 2007 Edition, from paragraph 3.1 of Supplement 10S-1 of 
NQA-1-1994 Edition.''
10 CFR 50.55a(b)(1)(x)(B) Visual Examination of Bolts, Studs, and Nuts: 
Second Provision
    Commenters were concerned with rationale given for the inclusion of 
this condition in the proposed rule. Commenters asserted that the 2017 
Edition paragraph NX-2582, in referencing ASTM F788 and ASTM F812 as 
acceptance criteria, only considers workmanship, finish, and appearance 
and does not consider structural integrity. The NRC agreed with the 
comment that the acceptance criteria for the condition should be 
clarified. Therefore, the NRC revised the condition in this final rule 
to require visual examination for discontinuities including cracks, 
bursts, seams, folds, thread lap, voids and tool marks. Section 
50.55a(b)(1)(x)(B) of this final rule reflects this change.

10 CFR 50.55a(b)(1)(xi)(A) Mandatory Appendix XXVI: First Provision

    Commenters were concerned that the requirement in the proposed 
condition for each fusing operator to perform qualification testing on 
each diameter, thickness and lot of material would entail significant 
added expense and hardship without a commensurate improvement in 
quality or safety. The NRC agreed with the comment and deleted the 
proposed requirement for operator performance qualification testing for 
butt fusion joints. Section 50.55a(b)(1)(xi)(A) of this final rule 
reflects this change.

[[Page 26562]]

10 CFR 50.55a(b)(1)(xi)(B) Mandatory Appendix XXVI: Second Provision
    Commenters were concerned that the requirement in the proposed 
condition for performance of both the bend test and the high speed 
tensile impact test to qualify fusing procedures and fusing operators 
for HDPE butt fusion joints, imposes additional hardship and increased 
cost without commensurate improvement in quality or safety. The NRC 
agreed with the comment and its supporting rationale. The NRC revised 
the condition to allow either test to qualify fusing procedures. 
Section 50.55a(b)(1)(xi)(B) of this final rule reflects this change.
10 CFR 50.55a(b)(1)(xi)(C) Mandatory Appendix XXVI: Third Provision
    Commenters were concerned that the requirement in the proposed 
condition for each fusing operator to perform qualification testing is 
redundant. Fusing operator performance qualification testing is 
performed in accordance with XXVI-4341 and XXVI-4342 using fusing 
procedures tested in accordance with XXVI-2300. Such fusing procedures 
define the electrofusion fitting material, pipe wall thickness, power 
supply and processor, to be used in production of each joint, so the 
fusing operator is already required to qualify using the same material 
and equipment. The NRC agreed with the comment and deleted the proposed 
requirement for operator performance qualification testing for 
electrofusion joints from this final rule. Section 50.55a(b)(1)(xi)(C) 
of this final rule reflects this change.
10 CFR 50.55a(b)(1)(xi)(D) Mandatory Appendix XXVI: Fourth Provision
    Commenters were concerned that the proposed condition, that would 
have required performance of both the crush test and the electrofusion 
bend test to qualify fusing procedures for HDPE electrofusion joints, 
is impractical, imposes additional hardship, and increases cost without 
commensurate improvement in quality or safety. The NRC agreed with the 
comment and its supporting rationale. The NRC deleted the proposed 
condition from this final rule.
10 CFR 50.55a(b)(1)(xi)(E) Mandatory Appendix XXVI: Fifth Provision
    Commenters were concerned that the proposed condition, that would 
have prohibited the use of electrofusion saddle joints and 
electrofusion saddle fittings, would lead to significant hardship 
without any improvement in quality or safety. The NRC agreed with the 
comment and its supporting rationale. The NRC deleted the proposed 
condition from this final rule.
10 CFR 50.55a(b)(1)(xii) Section III Condition: Certifying Engineer
    A commenter was concerned that the wording in the proposed 
condition was not clear. The NRC agreed with the commenter's proposed 
revision to clarify the rule language. The intent of the condition is 
to permit licensees and applicants to use a Certifying Engineer that is 
also a Registered Professional Engineer within one state of the United 
States. The revised rule language provides clarification to the NRC's 
intent of permitting licensees and applicants to use only a Certified 
Engineer that is also a Registered Professional Engineer. Section 
50.55a(b)(1)(xii) of this final rule reflects this change.

ASME BPV Code, Section XI

10 CFR 50.55a(b)(2)(xxv) Mitigation of Defects by Modification
    A commenter was concerned that, for modifications installed in 
inaccessible locations, the proposed condition leads to significant 
hardship without any improvement in quality or safety. The condition 
would require the Owner to perform follow-up examinations every 
refueling outage for modifications installed in inaccessible locations. 
The commenter recommends, as an alternative, that the condition be 
revised to validate corrosion rates at accessible degraded locations in 
the same piping system. The NRC agreed with the commenter's 
recommendation that the condition be revised. The NRC revised the 
condition to add two exceptions for buried piping: Sec.  
50.55a(b)(2)(xxv)(B)(3)(i), to address internal corrosion, and Sec.  
50.55a(b)(2)(xxv)(B)(3)(ii), to address external corrosion. Section 
50.55a(b)(2)(xxv)(B) of this final rule reflects this change.
10 CFR 50.55a(b)(2)(xxvi) Pressure Testing Class 1, 2 and 3 Mechanical 
Joints
    Commenters asserted that the proposed condition is unnecessary 
because the current practice of leakage testing and Quality Assurance 
(QA) program activities are adequate and the condition should not apply 
to installed items rotated from stock. The NRC partially agrees and 
partially disagrees with these comments. The NRC agreed that the 
condition should not apply to items rotated from stock. Since these 
items have previously been in service, these activities are essentially 
the same as maintenance where no pressure retaining components have 
been replaced. The NRC has previously stated that maintenance 
activities where no pressure retaining components are replaced are not 
subject to this condition. To address this comment and the comment 
regarding the specificity of what requires system leakage testing, the 
NRC revised the condition to state that the condition applies to those 
repair/replacement activities that require documentation on a Form NIS-
2. Section 50.55a(b)(2)(xxvi) of this final rule reflects this change.
10 CFR 50.55a(g)(4) Inservice Inspection Standards Requirement for 
Operating Plants
    A commenter was concerned that Sec.  50.55a(g)(4)(i) and Sec.  
50.55a(g)(4)(ii) require use of Appendix I from same edition and 
addenda as Appendix VIII. The commenter asserted that this is an issue 
because Appendix I references other parts of the Code. The commenter 
recommend that the NRC revise these conditions to say licensees are 
only required to implement the parts of Appendix I that are applicable 
to Appendix VIII. The NRC agreed with the comment. The NRC revised the 
last sentence of Sec.  50.55a(g)(4)(i) and (ii) in this final rule to 
specify that licensees using this option must also use the same edition 
and addenda of Appendix I, Subarticle I-3200, as Appendix VIII. Section 
50.55a(g)(4) of this final rule reflects this change.
10 CFR 50.55a(g)(6)(ii)(F)(11) Cast Stainless Steel
    A commenter was concerned that the proposed condition requires a 
significant expenditure of time and dose with no significant increase 
to safety. The proposed condition would require a second examination 
technique for all 92 welds even though two-thirds achieve 100 percent 
coverage. The NRC agrees with this comment. The NRC agrees that there 
would be limited improvement in safety and roughly the same number of 
proposed alternatives would be required. Therefore, there would be no 
improvement to regulatory efficiency. Accordingly, the NRC deleted the 
provision from this final rule. Section 50.55a(g)(6)(F)(11) of this 
final rule reflects this change.

ASME OM Code

10 CFR 50.55a(b)(3)(xi) OM Condition: Valve Position Indication
    Commenters requested clarification of the condition. Commenters 
were unclear regarding the condition requirements related to the MOV 
supplemental position verification test

[[Page 26563]]

interval. Another commenter suggested that the condition be modified to 
allow other NRC-approved test methods, such as a 10 CFR part 50, 
Appendix J leakage testing program, to verify obturator position. The 
NRC agreed with the comments that clarification would improve the 
condition. The NRC also clarified the condition to include a reference 
to the verification methods and frequencies of the mandatory appendices 
by specifying the phrase ``within the scope of Subsection ISTC 
including its mandatory appendices and their verification methods and 
frequencies.'' Section 50.55a(b)(3)(xi) of this final rule reflects 
this change. The NRC notes that licensees may request an NRC authorized 
alternative to this condition under 10 CFR 50.55a(z).
10 CFR 50.55a(b)(3)(xii) OM Condition: Air-Operated Valves (Appendix 
IV)
    Commenters were concerned that the proposed condition requiring the 
application of Appendix IV for AOV IST activities in the 2017 Edition 
of the ASME OM Code when implementing the 2015 Edition of ASME OM Code, 
was unnecessary and might cause confusion. After consideration of the 
public comments, the NRC agreed that incorporating by reference both 
the 2015 and 2017 Editions of the ASME OM Code in Sec.  50.55a in the 
same rulemaking will result in licensees applying the OM Code, 2017 
Edition, as incorporated by reference in Sec.  50.55a, when 
establishing their initial or subsequent 120-month IST program. In 
response to the comments, the NRC did not include the proposed 
condition in this final rule.
10 CFR 50.55a(f)(7) Inservice Testing Reporting Requirements
    Commenters recommended that the condition be revised to avoid 
excessive submittals of IST Program Test and Examination Plans (IST 
Plans). Commenters also requested clarification on requirements for 
submittal of augmented IST Plans. The NRC partially agrees and 
partially disagrees with these comments. For example, the intent of the 
proposed requirement in Sec.  50.55a(f)(7) was to allow the NRC to be 
aware of the current IST Plan for ASME Class 1, 2, and 3 pumps, valves, 
and dynamic restraints being implemented at each nuclear power plant 
such that immediate NRC review is possible in response to urgent 
requests by a licensee for relief from or alternatives to the Sec.  
50.55a requirements. At this time, the NRC does not consider 
requirements for submittal of the IST Plans for augmented IST programs, 
or deadlines for interim IST Plan updates, to be necessary in Sec.  
50.55a. The NRC may revisit the IST Plan submittal requirements 
(including the submittal of augmented IST Plans or the schedule of 
interim IST Plan updates) during a future rulemaking. The NRC notes 
that the submittal of IST Plans is needed to support the NRC's review 
of relief and alternative requests rather than review of IST plans 
themselves. Further, the NRC does not consider submittal requirements 
of IST Plans to need separate tracking. The IST Plan prepared at the 
beginning of a 120-month IST program interval will not be sufficient 
for all testing issues that might arise over a 10-year period.
    As a result of these comments, the NRC removed the condition from 
the final rule. The NRC will reconsider this condition if the reporting 
requirement is removed from a future Edition of the ASME OM Code.

V. Section-by-Section Analysis

Paragraph (a)(1)(i)

    This final rule revises paragraph (a)(1)(i) by removing the 
abbreviation definition for ASME BPV Code in the first sentence.

Paragraph (a)(1)(i)(E)

    This final rule adds new paragraphs (a)(1)(i)(E)(18) and (19) to 
include the 2015 and 2017 Editions of the ASME BPV Code.

Paragraph (a)(1)(ii)

    This final rule revises paragraphs (a)(1)(ii) to remove the acronym 
``BPV'' and replace it with ``Boiler and Pressure Vessel.''

Paragraph (a)(1)(ii)(C)

    This final rule revises paragraphs (a)(1)(ii)(C)(52) and (53) to 
remove parenthetical language and is adding new paragraphs 
(a)(1)(ii)(C)(54) and (55) to include the 2015 and 2017 Editions of the 
ASME BPV Code.

Paragraph (a)(1)(iii)(C)

    This final rule revises the reference from Code Case N-729-4 to N-
729-6.

Paragraph (a)(1)(iii)(D)

    This final rule revises the reference from Code Case N-770-2 to N-
770-5.

Paragraph (a)(1)(iv)

    This final rule removes parenthetical language.

Paragraph (a)(1)(iv)(C)

    This final rule adds new paragraphs (a)(1)(iv)(C)(2) and (3) to 
include the 2015 and 2017 Editions of the ASME OM Code.

Paragraph (a)(4)

    This final rule adds new paragraph (a)(4) to incorporate by 
reference the Electric Power Research Institute, Materials Reliability 
Program, 3420 Hillview Avenue, Palo Alto, CA 94304-1338; telephone: 1-
650-855-2000; https://www.epri.com.

Paragraph (a)(4)(i)

    This final rule adds new paragraph (a)(4)(i) to incorporate by 
reference the ``Materials Reliability Program: Topical Report for 
Primary Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement'' (MRP-335, Revision 3-A), EPRI approval date: November 
2016. Paragraph (a)(4)(ii) is added and reserved.

Paragraph (b)(1)

    This final rule changes the reference from the 2013 to the 2017 
Edition of the ASME BPV Code.

Paragraph (b)(1)(ii)

    This final rule changes the word ``Note'' to ``Footnote'' in Table 
1 of paragraph (b)(1)(ii) and revises the last reference in the table 
from the 2013 Edition to the 2017 Edition of the ASME BPV Code.

Paragraph (b)(1)(iii)

    This final rule changes the references from the 2008 Addenda to the 
2017 Edition of the ASME BPV Code.

Paragraph (b)(1)(v)

    This final rule revises paragraph (b)(1)(v) to limit the condition 
so that it applies to the exception to paragraph 3.1 of Supplement 10S-
1 of NQA-1-1994 Edition as referenced in NCA-4134.10(a), Section III, 
of the 1995 Edition through 2009b Addenda of the 2007 Edition.

Paragraph (b)(1)(vi)

    This final rule revises paragraph (b)(1)(vi) to replace ``the 
latest edition and addenda'' with ``all editions and addenda up to and 
including the 2013 Edition.''

Paragraph (b)(1)(vii)

    This final rule revises paragraph (b)(1)(vii) to replace ``the 2013 
Edition'' with ``all editions and addenda up to and including the 2017 
Edition.''

Paragraph (b)(1)(x)

    This final rule adds new paragraph (b)(1)(x) and its subparagraphs 
(A) and (B) to include two conditions necessary to maintain adequate 
standards for visual examinations of bolts, studs, and nuts.

[[Page 26564]]

Paragraph (b)(1)(xi)

    This final rule adds new paragraph (b)(1)(xi) and its subparagraphs 
(A) through (C) to include three conditions that are necessary to 
install safety-related Class 3 HDPE pressure piping in accordance with 
ASME BPV Code, Section III, Mandatory Appendix XXVI. The first two 
conditions apply to the 2015 and 2017 Editions of Section III. The 
third condition applies only to the 2017 Edition of Section III.

Paragraph (b)(1)(xii)

    This final rule adds new paragraph (b)(1)(xii) which applies to the 
use of certifying engineers.

Paragraph (b)(2)

    This final rule revises paragraph (b)(2) to change the reference 
from the 2013 Edition to the 2017 Edition of the ASME BPV Code.

Paragraph (b)(2)(vi)

    This final rule removes and reserves paragraph (b)(2)(vi).

Paragraph (b)(2)(vii)

    This final rule removes and reserves paragraph (b)(2)(vii).

Paragraph (b)(2)(ix)

    This final rule revises paragraph (b)(2)(ix) to add references to 
new paragraph (b)(2)(ix)(K) of this section, where applicable. It also 
replaces ``the latest edition and addenda'' with ``the 2015 Edition.''

Paragraph (b)(2)(ix)(K)

    This final rule adds new paragraph (b)(2)(ix)(K) to require visual 
examination of the moisture barrier materials installed in containment 
leak chase channel system closures at concrete floor interfaces. This 
condition is applicable to all editions and addenda of Section XI, 
Subsection IWE, of the ASME BPV Code, prior to the 2017 Edition, that 
are incorporated by reference in paragraph (b) of this section.

Paragraph (b)(2)(xvii)

    This final rule removes and reserves paragraph (b)(2)(xvii).

Paragraph (b)(2)(xviii)(D)

    This final rule revises paragraph (b)(2)(xviii)(D) to extend the 
applicability to users of the latest edition incorporated by reference 
in paragraph (a)(1)(ii) of this section.

Paragraph (b)(2)(xx)(B)

    This final rule revises paragraph (b)(2)(xx)(B) to clarify the 
NRC's expectations for system leakage tests performed in lieu of a 
hydrostatic pressure test, following repair/replacement activities 
performed by welding or brazing on a pressure retaining boundary using 
the 2003 Addenda through the latest edition and addenda of ASME BPV 
Code, Section XI incorporated by reference in paragraph (a)(1)(ii) of 
this section.

Paragraph (b)(2)(xx)(C)

    This final rule adds new paragraph (b)(2)(xx)(C) and subparagraphs 
(1) and (2) to include two conditions on the use of the alternative BWR 
Class 1 system leakage test described in IWA-5213(b)(2), IWB-5210(c) 
and IWB-5221(d) of the 2017 Edition of ASME BPV Code, Section XI.

Paragraph (b)(2)(xxi)(A)

    This final rule removes and reserves paragraph (b)(2)(xxi)(A).

Paragraph (b)(2)(xxi)(B)

    This final rule adds new paragraph (b)(2)(xxi)(B) and its 
subparagraphs (1) through (3) that include conditions on the use of the 
provisions of IWB-2500(f) and (g) and Notes 6 and 7 of Table IWB-2500-1 
of the 2017 Edition of ASME BPV Code, Section XI.

Paragraph (b)(2)(xxv)

    This final rule revises paragraph (b)(2)(xxv) introductory text and 
adds new subparagraphs (A) and (B) that prohibit the use of IWA-4340 in 
Section XI editions and addenda earlier than the 2011 Edition and 
allows the use of IWA-4340 in addenda and editions from the 2011 
Addenda through the latest edition incorporated by reference in this 
section under certain conditions.

Paragraph (b)(2)(xxvi)

    This final rule revises paragraph (b)(2)(xxvi) to clarify the NRC's 
expectations for pressure testing of ASME BPV Code Class 1, 2, and 3 
mechanical joints disassembled and reassembled during the performance 
of an ASME BPV Code, Section XI activity.

Paragraph (b)(2)(xxxii)

    This final rule revises the reporting requirements in paragraph 
(b)(2)(xxxii).

Paragraph (b)(2)(xxxiv)

    This final rule revises paragraph (b)(2)(xxxiv) and its 
subparagraph (B) to extend the applicability from the 2013 Edition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section.

Paragraph (b)(2)(xxxv)

    This final rule revises paragraph (b)(2)(xxxv) to designate the 
introductory text of paragraph (b)(2)(xxxv) minus the paragraph heading 
as subparagraph (A) and also adds new subparagraph (B).

Paragraph (b)(2)(xxxvi)

    This final rule revises the condition in paragraph (b)(2)(xxxvi) to 
include the use of the 2015 and 2017 Editions of ASME BPV Code, Section 
XI.

Paragraph (b)(2)(xxxviii)

    This final rule adds new paragraph (b)(2)(xxxviii) and its 
subparagraphs (A) and (B) that contain two conditions on the use of 
ASME BPV Code, Section XI, Appendix III, Supplement 2.

Paragraph (b)(2)(xxxix)

    This final rule adds new paragraph (b)(2)(xxxix) and its 
subparagraphs (A) and (B) that contain conditions on the use of IWA-
4421(c)(1) and IWA-4421(c)(2) of Section XI, in the 2017 Edition.

Paragraph (b)(2)(xl)

    This final rule adds new paragraph (b)(2)(xl) to include the 
requirements for the prohibitions on the use of IWB-3510.4(b).

Paragraph (b)(2)(xli)

    This final rule adds new paragraph (b)(2)(xli) to include the 
requirements for the prohibitions on the use of IWB-3112(a)(3) and IWC-
3112(a).

Paragraph (b)(2)(xlii)

    This final rule adds new paragraph (b)(2)(xlii) to include the 
requirements for the use of the provisions in Table IWB-2500-1, 
Examination Category B-F, Pressure Retaining Dissimilar Metal Welds in 
Vessel Nozzles, Item B5.11 and Item B5.71.

Paragraph (b)(3)

    This final rule revises paragraph (b)(3) to include Appendix IV in 
the list of Mandatory Appendices, remove the reference to the ``2012 
Edition'' and replaces it with ``the latest edition and addenda of the 
ASME OM Code incorporated by reference.'' It also revises the last 
sentence in the paragraph for clarity.

Paragraph (b)(3)(ii)

    This final rule revises paragraph (b)(3)(ii) to remove the 
reference to the ``2011 Addenda, and 2012 Edition'' and replace it with 
``the latest edition and addenda of the ASME OM Code incorporated by 
reference in paragraph (a)(1)(iv) of this section.''

Paragraph (b)(3)(iv)

    This final rule revises paragraph (b)(3)(iv) to update the 
conditions for

[[Page 26565]]

use of Appendix II of the ASME OM Code, 2003 Addenda through the 2015 
Edition.

Paragraph (b)(3)(viii)

    This final rule revises paragraph (b)(3)(viii) to remove the 
reference to the ``2011 Addenda, or 2012 Edition'' and to replace it 
with ``the latest edition and addenda of the ASME OM Code incorporated 
by reference in paragraph (a)(1)(iv) of this section.''

Paragraph (b)(3)(ix)

    This final rule revises paragraph (b)(3)(ix) to update the 
conditions for use of Subsection ISTF of the ASME OM Code, through the 
2012 Edition or 2015 Edition.

Paragraph (b)(3)(xi)

    This final rule revises paragraph (b)(3)(xi) to extend the 
applicability of the reference to the ASME OM Code, 2012 Edition 
through the latest edition and addenda of the ASME OM Code incorporated 
by reference in paragraph (a)(1)(iv) and to provide additional clarity 
regarding obturator position verification for valves with remote 
position indication.

Paragraphs (f)(4)(i) and (ii)

    This final rule revises paragraphs (f)(4)(i) and (ii) to change the 
time frame for complying with the latest edition and addenda of the 
ASME OM Code from 12 months to 18 months, both for the initial and 
successive IST programs.

Paragraph (g)(4)

    This final rule revises paragraph (g)(4) to remove the phrase 
``subject to the condition referenced in paragraph (b)(2)(vi) of this 
section.''

Paragraph (g)(4)(i)

    This final rule revises paragraph (g)(4)(i) to change the time 
frame for complying with the latest edition and addenda of the ASME BPV 
Codes, from 12 months to 18 months, for ISI programs. It also revises 
the last sentence in the paragraph to clarify the specific subarticle 
of Appendix I.

Paragraph (g)(4)(ii)

    This final rule revises paragraph (g)(4)(ii) to change the time 
frames for complying with the latest edition and addenda of the ASME 
BPV Codes, from 12 months to 18 months, for successive ISI programs, 
and replaces the date of August 17, 2017, with June 3, 2020. It also 
revises the last sentence in the paragraph to clarify the specific 
subarticle of Appendix I.

Paragraph (g)(6)(ii)(C)

    This final rule removes and reserves paragraph (g)(6)(ii)(C).

Paragraph (g)(6)(ii)(D)(1)

    This final rule revises paragraph (g)(6)(ii)(D)(1) to remove the 
date of August 17, 2017, and to replace that date with June 3, 2020. It 
also updates the reference from Code Case N-729-4 to Code Case N-729-6. 
It also revises the paragraph to include the conditions in paragraphs 
(2) through (8) and that licensees must be in compliance with these 
conditions by no later than 1 year from June 3, 2020.

Paragraph (g)(6)(ii)(D)(2)

    This final rule revises paragraph (g)(6)(ii)(D)(2) in its entirety.

Paragraph (g)(6)(ii)(D)(4)

    This final rule revises paragraph (g)(6)(ii)(D)(4) to update the 
reference to ASME BPV Code Case N-729 from revision 4 to revision 6.

Paragraphs (g)(6)(ii)(D)(5) through (8)

    This final rule adds new paragraphs (g)(6)(ii)(D)(5) through (8) to 
include the requirements for peening, baseline examinations, sister 
plants, and volumetric leak path assessment.

Paragraph (g)(6)(ii)(F)(1)

    This final rule revises paragraph (g)(6)(ii)(F)(1) to remove the 
date of August 17, 2017, and to replace that date with June 3, 2020. It 
also updates the reference from Code Case N-770-2 (revision 2) to Code 
Case N-770-5 (revision 5). It also revises the paragraph to include the 
conditions in paragraphs (g)(6)(ii)(F)(2) through (16) of this section 
and that licensees must be in compliance with these conditions by no 
later than 1 year from June 3, 2020.

Paragraph (g)(6)(ii)(F)(2)

    This final rule revises paragraph (g)(6)(ii)(F)(2) to include 
subparagraphs (i) through (v).

Paragraph (g)(6)(ii)(F)(3)

    This final rule removes and reserves paragraph (g)(6)(ii)(F)(3).

Paragraph (g)(6)(ii)(F)(4)

    This final rule revises paragraph (g)(6)(ii)(F)(4) to change the 
reference from ASME BPV Code Case N-770-2 (revision 2) to Code Case N-
770-5 (revision 5).

Paragraph (g)(6)(ii)(F)(6)

    This final rule revises paragraph (g)(6)(ii)(F)(6) to provide 
greater clarity of the requirements that must be met.

Paragraph (g)(6)(ii)(F)(9)

    This final rule revises paragraph (g)(6)(ii)(F)(9) to include 
subparagraphs (i) through (iii).

Paragraph (g)(6)(ii)(F)(10)

    This final rule revises paragraph (g)(6)(ii)(F)(10) from ASME BPV 
Code Case N-770-2 (revision 2) to N-770-5 (revision 5).

Paragraph (g)(6)(ii)(F)(11)

    This final rule removes and reserves paragraph (g)(6)(ii)(F)(11).

Paragraph (g)(6)(ii)(F)(13)

    This final rule revises paragraph (g)(6)(ii)(F)(13) to include 
inspection categories B-1, B-2, N-1, N-2 and O.

Paragraph (g)(6)(ii)(F)(14) through (16)

    This final rule adds new paragraphs (g)(6)(ii)(F)(14) through (16) 
to contain the new requirements: excavate and weld repair cold leg, 
cracked excavate and weld repair, and partial arc excavate and weld 
repair.

VI. Generic Aging Lessons Learned Report

Background

    In December 2010, the NRC issued ``Generic Aging Lessons Learned 
(GALL) Report,'' NUREG-1801, Revision 2 (ADAMS Accession No. 
ML103490041), for applicants to use in preparing license renewal 
applications. The GALL Report provides aging management programs (AMPs) 
that the NRC has concluded are sufficient for aging management in 
accordance with the license renewal rule, as required in Sec.  
54.21(a)(3). In addition, the ``Standard Review Plan for Review of 
License Renewal Applications for Nuclear Power Plants,'' (SRP-LR), 
NUREG-1800, Revision 2 (ADAMS Accession No. ML103490036), was issued in 
December 2010, to ensure the quality and uniformity of NRC staff 
reviews of license renewal applications and to present a well-defined 
basis on which the NRC staff evaluates the applicant's aging management 
programs and activities. In April 2011, the NRC also issued 
``Disposition of Public Comments and Technical Bases for Changes in the 
License Renewal Guidance Documents NUREG-1801 and NUREG-1800,'' NUREG-
1950 (ADAMS Accession No. ML11116A062), which describes the technical 
bases for the changes in Revision 2 of the GALL Report and Revision 2 
of the Standard Review Plan for Review of License Renewal Applications.
    Revision 2 of the GALL Report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3,

[[Page 26566]]

XI.M5, XI.M6, XI.M11B and XI.S3, describes the evaluation and technical 
bases for determining the sufficiency of ASME BPV Code Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL for managing aging during the period of 
extended operation (i.e., up to 60 years of operation). In addition, 
many other AMPs in the GALL Report rely, in part but to a lesser 
degree, on the requirements specified in the ASME BPV Code, Section XI. 
Revision 2 of the GALL report also states that the 1995 Edition through 
the 2004 Edition of the ASME BPV Code, Section XI, Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL, as modified and limited by Sec.  50.55a, 
were found to be acceptable editions and addenda for complying with the 
requirements of Sec.  54.21(a)(3), unless specifically noted in certain 
sections of the GALL report. The GALL report further states that future 
Federal Register documents that amend Sec.  50.55a will discuss the 
acceptability of editions and addenda more recent than the 2004 Edition 
for their applicability to license renewal. In a final rule issued on 
June 21, 2011 (76 FR 36232), subsequent to Revision 2 of the GALL 
report, the NRC also found that the 2004 Edition with the 2005 Addenda 
through the 2007 Edition with the 2008 Addenda of Section XI of the 
ASME BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject 
to the conditions in Sec.  50.55a, are acceptable for the AMPs in the 
GALL report and the conclusions of the GALL report remain valid with 
the augmentations specifically noted in the GALL report. In a final 
rule issued on July 18, 2017 (82 FR 32934), the NRC further finds that 
the 2009 Addenda through the 2013 Edition of Section XI of the ASME BPV 
Code, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in Sec.  50.55a, will be acceptable for the AMPs in the GALL 
report.
    In July 2017, the NRC issued ``Generic Aging Lessons Learned for 
Subsequent License Renewal (GALL-SLR) Report,'' NUREG-2191 (ADAMS 
Accession Nos. ML17187A031 and ML17187A204), for applicants to use in 
preparing applications for subsequent license renewal. The GALL-SLR 
report provides AMPs that are sufficient for aging management for the 
subsequent period of extended operation (i.e., up to 80 years of 
operation), as required in Sec.  54.21(a)(3). The NRC also issued 
``Standard Review Plan for Review of Subsequent License Renewal 
Applications for Nuclear Power Plants,'' (SRP-SLR), NUREG-2192 in July 
2017 (ADAMS Accession No. ML17188A158). In a similar manner as the GALL 
report does, the GALL-SLR report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3, XI.11B, and XI.S3, describes the evaluation and technical bases 
for determining the sufficiency of ASME BPV Code Subsections IWB, IWC, 
IWD, IWE, IWF, or IWL for managing aging during the subsequent period 
of extended operation. Many other AMPs in the GALL-SLR report rely, in 
part but to a lesser degree, on the requirements specified in the ASME 
BPV Code, Section XI. The GALL-SLR report also indicates that the 1995 
Edition through the 2013 Edition of the ASME BPV Code, Section XI, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in Sec.  50.55a, are acceptable for complying with the 
requirements of Sec.  54.21(a)(3), unless specifically noted in certain 
sections of the GALL-SLR report.

Evaluation With Respect to Aging Management

    As part of this final rule, the NRC evaluated whether those AMPs in 
the GALL report and GALL-SLR report which rely upon Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL of Section XI in the editions and addenda of 
the ASME BPV Code incorporated by reference into Sec.  50.55a, in 
general continue to be acceptable if the AMP relies upon these 
Subsections in the 2015 Edition and the 2017 Edition. The NRC finds 
that the 2015 Edition and the 2017 Edition of Section XI of the ASME 
BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to 
the conditions of this rule, are acceptable for the AMPs in the GALL 
report and GALL-SLR report and the conclusions of the GALL report and 
GALL-SLR report remain valid with the exception of augmentation, 
specifically noted in those reports. Accordingly, an applicant for 
license renewal (including subsequent license renewal) may use, in its 
plant-specific license renewal application, Subsections IWB, IWC, IWD, 
IWE, IWF, or IWL of Section XI of the 2015 Edition and the 2017 Edition 
of the ASME BPV Code, subject to the conditions in this rule, without 
additional justification. Similarly, a licensee approved for license 
renewal that relied on the AMPs may use Subsections IWB, IWC, IWD, IWE, 
IWF, or IWL of Section XI of the 2015 Edition and the 2017 Edition of 
the ASME BPV Code. However, applicants must assess and follow 
applicable NRC requirements with regard to licensing basis changes and 
evaluate the possible impact on the elements of existing AMPs.
    Some of the AMPs in the GALL report and GALL-SLR report recommend 
augmentation of certain Code requirements in order to ensure adequate 
aging management for license renewal. The technical and regulatory 
aspects of the AMPs for which augmentations are recommended also apply 
if the 2015 Edition and the 2017 Edition of Section XI of the ASME BPV 
Code are used to meet the requirements of Sec.  54.21(a)(3). The NRC 
staff evaluated the changes in the 2015 Edition and the 2017 Edition of 
Section XI of the ASME BPV Code to determine if the augmentations 
described in the GALL report and GALL-SLR report remain necessary; the 
NRC staff's evaluation has concluded that the augmentations described 
in the GALL and GALL-SLR reports are necessary to ensure adequate aging 
management.
    For example, GALL-SLR report AMP XI.S3, ``ASME Section XI, 
Subsection IWF'', recommends that volumetric examination consistent 
with that of ASME BPV Code, Section XI, Table IWB-2500-1, Examination 
Category B-G-1 should be performed to detect cracking for high strength 
structural bolting (actual measured yield strength greater than or 
equal to 150 kilopound per square inch (ksi)) in sizes greater than 1 
inch nominal diameter. The GALL-SLR report also indicates that this 
volumetric examination may be waived with adequate plant-specific 
justification. This guidance for aging management in the GALL-SLR 
report is the augmentation of the visual examination specified in 
Subsection IWF of the 2015 Edition and the 2017 Edition of ASME BPV 
Code, Section XI.
    A license renewal applicant may either augment its AMPs as 
described in the GALL report and GALL-SLR report (for operation up to 
60 and 80 years respectively), or propose alternatives for the NRC to 
review as part of the applicant's plant-specific justification for its 
AMPs.

VII. Regulatory Flexibility Certification

    Under the Regulatory Flexibility Act (5 U.S.C. 605(b)), the NRC 
certifies that this rule does not have a significant economic impact on 
a substantial number of small entities. This final rule affects only 
the licensing and operation of nuclear power plants. The companies that 
own these plants do not fall within the scope of the definition of 
``small entities'' set forth in the Regulatory Flexibility Act or the 
size standards established by the NRC (Sec.  2.810).

VIII. Regulatory Analysis

    The NRC has prepared a final regulatory analysis on this 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the NRC. The regulatory analysis is

[[Page 26567]]

available as indicated in the ``Availability of Documents'' section of 
this document.

IX. Backfitting and Issue Finality

Introduction

    The NRC's Backfit Rule in Sec.  50.109 states that the NRC shall 
require the backfitting of a facility only when it finds the action to 
be justified under specific standards stated in the rule. Section 
50.109(a)(1) defines backfitting as the modification of or addition to 
systems, structures, components, or design of a facility; the design 
approval or manufacturing license for a facility; or the procedures or 
organization required to design, construct, or operate a facility. Any 
of these modifications or additions may result from a new or amended 
provision in the NRC's rules or the imposition of a regulatory position 
interpreting the NRC's rules that is either new or different from a 
previously applicable NRC position after issuance of the construction 
permit or the operating license or the design approval.
    Section 50.55a requires nuclear power plant licensees to:
     Construct ASME BPV Code Class 1, 2, and 3 components in 
accordance with the rules provided in Section III, Division 1, of the 
ASME BPV Code (``Section III'').
     Inspect Class 1, 2, 3, Class MC, and Class CC components 
in accordance with the rules provided in Section XI, Division 1, of the 
ASME BPV Code (``Section XI'').
     Test pumps, valves, and dynamic restraints (snubbers) in 
accordance with the rules provided in the ASME OM Code.
    This final rule is incorporating by reference the 2015 and 2017 
Editions to the ASME BPV Code, Section III, Division 1 and ASME BPV 
Code, Section XI, Division 1, as well as the 2015 and 2017 Editions to 
the ASME OM Code and Code Cases N-770-5 and N-729-6.
    The ASME BPV and OM Codes are national consensus standards 
developed by participants with broad and varied interests, in which all 
interested parties (including the NRC and utilities) participate. A 
consensus process involving a wide range of stakeholders is consistent 
with the NTTAA, inasmuch as the NRC has determined that there are sound 
regulatory reasons for establishing regulatory requirements for design, 
maintenance, ISI, and IST by rulemaking. The process also facilitates 
early stakeholder consideration of backfitting issues. Thus, the NRC 
believes that the NRC need not address backfitting with respect to the 
NRC's general practice of incorporating by reference updated ASME 
Codes.

Overall Backfitting Considerations: Section III of the ASME BPV Code

    Incorporation by reference of more recent editions and addenda of 
Section III of the ASME BPV Code does not affect a plant that has 
received a construction permit or an operating license or a design that 
has been approved. This is because the edition and addenda to be used 
in constructing a plant are, under Sec.  50.55a, determined based on 
the date of the construction permit, and are not changed thereafter, 
except voluntarily by the licensee. The incorporation by reference of 
more recent editions and addenda of Section III ordinarily applies only 
to applicants after the effective date of the final rule incorporating 
these new editions and addenda. Thus, incorporation by reference of a 
more recent edition and addenda of Section III does not constitute 
``backfitting'' as defined in Sec.  50.109(a)(1).

Overall Backfitting Considerations: Section XI of the ASME BPV Code and 
the ASME OM Code

    Incorporation by reference of more recent editions and addenda of 
Section XI of the ASME BPV Code and the ASME OM Code affects the ISI 
and IST programs of operating reactors. However, the Backfit Rule 
generally does not apply to incorporation by reference of later 
editions and addenda of the ASME BPV Code (Section XI) and OM Code. As 
previously mentioned, the NRC's longstanding regulatory practice has 
been to incorporate later versions of the ASME Codes into Sec.  50.55a. 
Under Sec.  50.55a, licensees shall revise their ISI and IST programs 
every 120 months to the latest edition and addenda of Section XI of the 
ASME BPV Code and the ASME OM Code incorporated by reference into Sec.  
50.55a 18 months before the start of a new 120-month ISI and IST 
interval. Thus, when the NRC approves and requires the use of a later 
version of the Code for ISI and IST, it is implementing this 
longstanding regulatory practice and requirement.
    Other circumstances where the NRC does not apply the Backfit Rule 
to the approval and requirement to use later Code editions and addenda 
are as follows:
    1. When the NRC takes exception to a later ASME BPV Code or OM Code 
provision but merely retains the current existing requirement, 
prohibits the use of the later Code provision, limits the use of the 
later Code provision, or supplements the provisions in a later Code. 
The Backfit Rule does not apply because the NRC is not imposing new 
requirements. However, the NRC explains any such exceptions to the Code 
in the Statement of Considerations and regulatory analysis for the 
rule.
    2. When an NRC exception relaxes an existing ASME BPV Code or OM 
Code provision but does not prohibit a licensee from using the existing 
Code provision. The Backfit Rule does not apply because the NRC is not 
imposing new requirements.
    3. Modifications and limitations imposed during previous routine 
updates of Sec.  50.55a have established a precedent for determining 
which modifications or limitations are backfits, or require a backfit 
analysis (e.g., final rule dated September 10, 2008 [73 FR 52731], and 
a correction dated October 2, 2008 [73 FR 57235]). The application of 
the backfit requirements to modifications and limitations in the 
current rule are consistent with the application of backfit 
requirements to modifications and limitations in previous Sec.  50.55a 
rulemakings.
    The incorporation by reference and adoption of a requirement 
mandating the use of a later ASME BPV Code or OM Code may constitute 
backfitting in some circumstances. In these cases, the NRC would 
perform a backfit analysis or documented evaluation in accordance with 
Sec.  50.109. These include the following:
    1. When the NRC endorses a later provision of the ASME BPV Code or 
OM Code that takes a substantially different direction from the 
existing requirements, the action is treated as a backfit (e.g., 61 FR 
41303; August 8, 1996).
    2. When the NRC requires implementation of a later ASME BPV Code or 
OM Code provision on an expedited basis, the action is treated as a 
backfit. This applies when implementation is required sooner than it 
would be required if the NRC simply endorsed the Code without any 
expedited language (e.g., 64 FR 51370; September 22, 1999).
    3. When the NRC takes an exception to an ASME BPV Code or OM Code 
provision and imposes a requirement that is substantially different 
from the existing requirement as well as substantially different from 
the later Code (e.g., 67 FR 60529; September 26, 2002).

Detailed Backfitting Discussion: Changes Beyond Those Necessary To 
Incorporate by Reference the New ASME BPV and OM Code Provisions

    This section discusses the backfitting considerations for all the 
changes to

[[Page 26568]]

Sec.  50.55a that go beyond the minimum changes necessary and required 
to adopt the new ASME Code Addenda into Sec.  50.55a.

ASME BPV Code, Section III

    1. Add Sec.  50.55a(b)(1)(x) to require compliance with two new 
conditions related to visual examination of bolts studs and nuts. 
Visual examination is one of the processes for acceptance of the final 
product to ensure its structural integrity and its ability to perform 
its intended function. The 2015 Edition of the ASME Code contains 
requirements for visual inspection of these components, however, the 
2017 Edition does not require these visual examinations to be performed 
in accordance with NX-5100 and NX-5500. Therefore, the NRC is adding 
two conditions to ensure adequate procedures remain and qualified 
personnel remain capable of determining the structural integrity of 
these components. Since the new conditions restore requirements that 
were removed from the latest edition of the ASME Code, the conditions 
do not constitute a new or changed NRC position. Therefore, this change 
is not a backfit.
    2. Add Sec.  50.55a(b)(1)(xi) to require conditions on the use of 
ASME BPV Code, Section III, Appendix XXVI for installation of high 
density polyethylene (HDPE) pressure piping. This Appendix is new in 
the 2015 Edition of Section III, since it is the first time the ASME 
BPV Code has provided rules for the use of polyethylene piping. The use 
of HDPE is newly allowed by the Code, which provides alternatives to 
the use of current materials. Therefore, this change is not a backfit.
    3. Add Sec.  50.55a(b)(1)(xii) to prohibit applicants and licensees 
from using a Certifying Engineer who is not also a Registered 
Professional Engineer for code-related activities that are applicable 
to U.S. nuclear facilities regulated by the NRC. In the 2017 Edition of 
ASME BPV Code, Section III, Subsection NCA, the several Subsections 
were updated to replace the term ``Registered Professional Engineer,'' 
with term ``Certifying Engineer'' to be consistent with ASME BPV Code 
Section III Mandatory Appendix XXIII.
    The NRC reviewed these changes and has determined that the use of a 
Certifying Engineer instead of a Registered Professional Engineer is 
only applicable for non-U.S. nuclear facilities. Since the use of a 
Certifying Engineer is newly allowed by the Code, the addition of the 
condition that prohibits the use of a Certifying Engineer that is not a 
Registered Professional Engineer for code-related activities is not a 
backfit.

ASME BPV Code, Section XI

    1. Revise Sec.  50.55a(b)(2)(ix) to require compliance with new 
condition Sec.  50.55a(b)(2)(ix)(K). The NRC has developed condition 
Sec.  50.55a(b)(2)(ix)(K) to ensure containment leak-chase channel 
systems are properly inspected. This condition serves to clarify the 
NRC's existing expectations, as described in inspection reports and IN 
2014-07, and will be applicable to all editions of the ASME Code, prior 
to the 2017 Edition. The NRC considers this condition a clarification 
of the existing expectations and, therefore, does not consider this 
condition a backfit.
    As noted previously, after issuance of the IN, the NRC received 
feedback during an August 22, 2014, public meeting between NRC and ASME 
management (ADAMS Accession No. ML14245A003), noting that the IN 
guidance appeared to be in conflict with ASME Section XI Interpretation 
XI-1-13-10. In response to the comment during the public meeting, the 
NRC issued a letter to ASME (ADAMS Accession No. ML14261A051), which 
stated the NRC believes the IN is consistent with the requirements in 
the ASME Code and restated the existing NRC staff position. ASME 
responded to the NRC's letter (ADAMS Accession No. ML15106A627) and 
noted that a condition in the regulations may be appropriate to clarify 
the NRC's position.
    2. Revise Sec.  50.55a(b)(2)(xx)(B) to clarify the condition with 
respect to the NRC's expectations for system leakage tests performed in 
lieu of a hydrostatic pressure test following repair/replacement 
activities performed by welding or brazing on a pressure retaining 
boundary using the 2003 Addenda through the latest edition and addenda 
of ASME BPV Code, Section XI incorporated by reference in paragraph 
Sec.  50.55a(a)(1)(ii). This provision requires the licensee perform 
the applicable nondestructive testing that would be required by the 
1992 Edition or later of ASME BPV Code, Section III. The nondestructive 
examination method (e.g. surface, volumetric, etc.) and acceptance 
criteria of the 1992 Edition or later of Section III shall be met and a 
system leakage test be performed in accordance with IWA-5211(a). The 
actual nondestructive examination and pressure testing may be performed 
using procedures and personnel meeting the requirements of the 
licensee's/applicant's current ISI code of record required by Sec.  
50.55a(g)(4). The condition does not constitute a new or changed NRC 
position. Therefore, the revision of this condition is not a backfit
    3. Add Sec.  50.55a(b)(2)(xx)(C) to place two conditions on the use 
of the alternative BWR Class 1 system leakage test described in IWA-
5213(b)(2), IWB-5210(c) and IWB-5221(d) of the 2017 Edition of ASME 
Section XI. This is a new pressure test allowed by the Code at a 
reduced pressure as an alternative to the pressure test currently 
required. This allows a reduction in the requirements which is 
consistent with several NRC-approved alternatives/relief requests. 
Therefore, this change is not a backfit.
    4. Add Sec.  50.55a(b)(2)(xxi)(B) to require the plant-specific 
evaluation demonstrating the criteria of IWB-2500(f) are met and 
maintained in accordance with the Owners requirements, to prohibit use 
of the provisions of IWB-2500(f) and Table IWB-2500-1 Note 6 for of 
Examination Category B-D Item Numbers B3.90 and B3.100 for plants with 
renewed licenses, and to restrict the provisions of IWB-2500(g) and 
Table IWB-2500-1 Notes 6 and 7 for examination of Examination Category 
B-D Item Numbers B3.90 and B3.100. The condition does not allow the use 
of these provisions to eliminate the preservice or inservice volumetric 
examination of plants with a Combined Operating License pursuant to 10 
CFR part 52, or a plant that receives its operating license after 
October 22, 2015. This revision applies the current requirements for 
use of these provisions as currently described in ASME Code Case N-702, 
which are currently allowed through Regulatory Guide 1.147, Revision 
19. Therefore, the NRC does not consider the clarification to be a 
change in requirements. Therefore, this change is not a backfit.
    5. Revise the condition found in Sec.  50.55a(b)(2)(xxv) to allow 
the use of IWA-4340 of Section XI, 2011 Addenda through 2017 Edition 
with conditions.
    Add Sec.  50.55a(b)(2)(xxv)(A) which will continue the prohibition 
of IWA-4340 for Section XI editions and addenda prior to the 2011 
Addenda. This prohibition applies the current requirements for use of 
these provision, therefore, the NRC does not consider the addition of 
Sec.  50.55a(b)(2)(xxv)(A) to be a change in requirements. Therefore, 
this change is not a backfit.
    Add Sec.  50.55a(b)(2)(xxv)(B) which will allow the use of IWA-4340 
of Section XI, 2011 Addenda through 2017 Edition with five conditions.
     The first condition prohibits the use of IWA-4340 on 
crack-like defects or

[[Page 26569]]

those associated with flow accelerated corrosion.
    The design requirements and potentially the periodicity of follow-
up inspections might not be adequate for crack-like defects that could 
propagate much faster than defects due to loss of material. Prior to 
the change to allow the use of IWA-4340, the provisions of this 
subsubarticle were not permitted for any type of defects. By 
establishment of the new conditions, the NRC will allow the use of IWA-
4340 for defects such as wall loss due to general corrosion. 
Establishing a condition to not allow the use of IWA-4340 for crack-
like defects does not constitute a new or changed NRC position. 
Therefore, the revision of this condition associated with crack-like 
defects is not a backfit.
    As established in NUREG-1801, ``Generic Aging Lessons Learned 
(GALL) Report'', Revision 2, effective management of flow accelerated 
corrosion entails: (a) An analysis to determine critical locations, (b) 
limited baseline inspections to determine the extent of thinning at 
these locations, (c) use of a predictive Code (e.g., CHECKWORKS); and 
(d) follow-up inspections to confirm the predictions, or repairing or 
replacing components as necessary. These provisions are not included in 
IWA-4340. In addition, subparagraph IWA-4421(c)(2) provides provisions 
for restoring minimum required wall thickness by welding or brazing, 
which can be used to mitigate a defect associated with flow accelerated 
corrosion. The condition related to flow accelerated corrosion does not 
constitute a new or changed NRC position. Therefore, the revision of 
this condition is not a backfit.
     The second condition requires the design of a modification 
that mitigates a defect to incorporate a loss of material rate either 2 
times the actual measured corrosion rate in that pipe location, or 4 
times the estimated maximum corrosion rate for the piping system. This 
condition is consistent with Code Case N-789, ``Alternative 
Requirements for Pad Reinforcement of Class 2 and 3 Moderate- Energy 
Carbon Steel Piping, Section XI, Division 1,'' Section 3, ``Design.'' 
The NRC has endorsed Code Case 789 in Regulatory Guide 1.147, 
``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1.'' The condition does not constitute a new or changed NRC 
position. Therefore, the revision of this condition is not a backfit.
     The third condition requires the licensee to perform a 
wall thickness examination in the vicinity of the modification and 
relevant pipe base metal during each refueling outage cycle to detect 
propagation of the defect unless the projected flaw propagation has 
been validated in two refueling outage cycles subsequent to the 
installation of the modification. Where the projected flaw growth has 
been validated, the modification shall be examined at half its expected 
life or once per interval whichever is smaller. This condition is 
consistent with Code Case N-789, Section 8, ``Inservice Monitoring,'' 
which requires follow-up wall thickness measurements to verify that the 
minimum design thicknesses are maintained. The follow-up examination 
requirements in IWA-4340 are inconsistent with the NRC endorsement of 
Code Case 789 in Regulatory Guide 1.147 in that the inspections can be 
limited to demonstrating that the flaw has not propagated into material 
credited for structural integrity without validating the project flaw 
growth. Two exceptions allow for different follow-up examinations of 
buried piping where the loss of material has occurred due to internal 
or external corrosion. The condition is part of a relaxation on the use 
of IWA-4340 of Section XI, 2011 Addenda through 2017 Edition. Therefore 
this condition is not a backfit.
    6. Revise Sec.  50.55a(b)(2)(xxvi) to require that a system leakage 
test be conducted after implementing a repair replacement activity on a 
mechanical joint greater than NPS-1. The revision will also clarify 
what Code edition/addenda may be used when conducting the pressure 
test. This revision clarifies the current requirements, which the NRC 
considers to be consistent with the meaning and intent of the current 
requirements. Therefore, the NRC does not consider the clarification to 
be a change in requirements. Therefore, this change is not a backfit.
    7. Revise Sec.  50.55a(b)(2)(xxxii) to clarify the requirement to 
submit Summary Reports pre-2015 Edition and Owner Activity Reports in 
the 2015 Edition of the ASME BPV Code. This revision clarifies the 
current requirements, which the NRC considers to be consistent with the 
meaning and intent of the current requirements. Therefore, the NRC does 
not consider the clarification to be a change in requirements. 
Therefore, this change is not a backfit.
    8. Add Sec.  50.55a(b)(2)(xxxv)(B) which conditions the use of 2015 
Edition of ASME BPV Code, Section XI, Appendix A, paragraph A-4200(c), 
to define RTKIa in equation for U.S. Units as 
RTKIa = T0 + 90.267 exp(-0.003406T0) 
in lieu of the equation shown in the Code. When the equation was 
converted from SI units to U.S. Customary units, a mistake was made 
which makes the equation erroneous. The equation shown above for 
RTKIa is the correct formula. This is part of the newly 
revised Code, and the addition of this condition is not a new 
requirement and therefore not a backfit.
    9. Revise Sec.  50.55a(b)(2)(xxxvi) to extend the applicability to 
use of the 2015 and 2017 Editions of Section XI of the ASME BPV Code. 
The condition was added in the 2009-2013 rulemaking. ASME did not make 
changes in the 2015 or 2017 Editions of the ASME BPV Code; therefore, 
the condition still applies. The NRC considers this revision to the 
condition to be consistent with the meaning and intent of the current 
requirements. Therefore, the NRC does not consider the extension of the 
condition to be a change in requirements. Therefore, this change is not 
a backfit.
    10. Add Sec.  50.55a(b)(2)(xxxviii) to condition ASME BPV Code, 
Section XI, Appendix III, Supplement 2. Supplement 2 is closely based 
on ASME Code Case N-824, which was incorporated by reference with 
conditions in Sec.  50.55a(a)(3)(ii). The conditions on ASME BPV Code, 
Section XI, Appendix III, Supplement 2 are consistent with the 
conditions on ASME Code Case N-824. Therefore, the NRC does not 
consider this a new requirement. Therefore, this change is not a 
backfit.
    11. Add Sec.  50.55a(b)(2)(xxxix) to condition the use of Section 
XI, IWA-4421(c)(1) and IWA-4421(c)(2). The NRC considers these 
conditions necessary as part of the allowance to use IWA-4340. The 
condition on the use of IWA-4421(c)(1) and IWA-4421(c)(2) does not 
constitute a new or changed NRC position. Therefore, the addition of 
this condition is not a backfit.
    12. Add Sec.  50.55a(b)(2)(xl) to prohibit the use of ASME BPV 
Code, Section XI, 2017 Edition, Subparagraphs IWB-3510.4(b)(4) and IWB-
3510.4(b)(5). The condition does not change the current material 
requirements because the currently required testing to meet the 
material requirements for those materials addressed by the new 
condition would continue to be performed per the existing requirements. 
Therefore, this condition on the use of IWB-3510.4(b) does not 
constitute a new or changed NRC position. Therefore, the addition of 
this condition is not a backfit.
    13. Add Sec.  50.55a(b)(2)(xli) to prohibit the use of ASME BPV 
Code, Section XI, Subparagraphs IWB-3112(a)(3) and IWC-3112(a)(3) in 
the 2013 Edition of Section XI through the latest edition and addenda 
incorporated by reference in

[[Page 26570]]

paragraph (a)(1)(ii). The condition is consistent with the NRC's 
current prohibition of these items as discussed in Regulatory Guide 
1.193 in the discussion of ASME Code Case N-813. Therefore, this 
condition does not constitute a new or changed NRC position. Therefore, 
the addition of this condition is not a backfit.
    14. Add Sec.  50.55a(b)(2)(xlii) to provide conditions for 
Examination Category B-F, Item B5.11 and Item B5.71 in the 2011a 
Addenda through the latest edition and addenda incorporated by 
reference in previous paragraphs (a)(1)(ii) of this section. The 
conditions are consistent with the conditions on the use of ASME Code 
Case N-799 in Regulatory Guide 1.147, Revision 19. The conditions being 
added in this final rule are a simplification and relaxation of the 
current conditions on the use of Code Case N-799. Therefore, the 
addition of these conditions is not a backfit.
    15. Revise Sec.  50.55a(g)(6)(ii)(D) to implement Code Case N-729-
6. On March 3, 2016, the ASME approved the sixth revision of ASME BPV 
Code Case N-729, (N-729-6). The NRC is revising the requirements of 
Sec.  50.55a(g)(6)(ii)(D) to require licensees to implement ASME BPV 
Code Case N-729-6, with conditions. The ASME BPV Code Case N-729-6 
contains similar requirements as N-729-4; however, N-729-6 also 
contains new requirements to address peening mitigation and inspection 
relief for replaced reactor pressure vessel heads with nozzles and 
welds made of more crack resistant materials. The new NRC conditions on 
the use of ASME BPV Code Case N-729-6 address operational experience, 
clarification of implementation, and the use of alternatives to the 
code case.
    The current regulatory requirements for the examination of 
pressurized water reactor upper RPV heads that use nickel-alloy 
materials are provided in Sec.  50.55a(g)(6)(ii)(D). This section was 
first created by rulemaking, dated September 10, 2008, (73 FR 52730) to 
require licensees to implement ASME BPV Code Case N-729-1, with 
conditions, instead of the examinations previously required by the ASME 
BPV Code, Section XI. The action did constitute a backfit; however, the 
NRC concluded that imposition of ASME BPV Code Case N-729-1, as 
conditioned, constituted an adequate protection backfit.
    The General Design Criteria (GDC) for nuclear power plants 
(appendix A to 10 CFR part 50) or, as appropriate, similar requirements 
in the licensing basis for a reactor facility, provide bases and 
requirements for NRC assessment of the potential for, and consequences 
of, degradation of the reactor coolant pressure boundary (RCPB). The 
applicable GDC include GDC 14 (Reactor Coolant Pressure Boundary), GDC 
31 (Fracture Prevention of Reactor Coolant Pressure Boundary), and GDC 
32 (Inspection of Reactor Coolant Pressure Boundary). General Design 
Criterion 14 specifies that the RCPB be designed, fabricated, erected, 
and tested so as to have an extremely low probability of abnormal 
leakage, of rapidly propagating failure, and of gross rupture. General 
Design Criterion 31 specifies that the probability of rapidly 
propagating fracture of the RCPB be minimized. General Design Criterion 
32 specifies that components that are part of the RCPB have the 
capability of being periodically inspected to assess their structural 
and leaktight integrity.
    The NRC concludes that incorporation by reference of Code Case N-
729-6, as conditioned, into Sec.  50.55a as a mandatory requirement 
will continue to ensure reasonable assurance of adequate protection of 
public health and safety. Updating the regulations to require using 
ASME BPV Code Case N-729-6, with conditions, ensures that potential 
flaws will be detected before they challenge the structural or 
leaktight integrity of the reactor pressure vessel upper head within 
current nondestructive examination limitations. The code case 
provisions and the NRC's conditions on examination requirements for 
reactor pressure vessel upper heads are essentially the same as those 
established under ASME BPV Code Case N-729-4, as conditioned. 
Exceptions include: (1) An introduction of examination relief for upper 
heads with Alloy 690 penetration nozzles to be examined volumetrically 
every 20 years in accordance with Table 1 of ASME BPV Code Case N-729-
6, (2) introduction of peening as a mitigation technique along with 
requirements for peening and inspection relief following peening and 
(3) substitution of a volumetric leak path examination for a required 
surface examination if a bare metal visual examination identifies a 
possible indication of leakage.
    The NRC continues to find that examinations of reactor pressure 
vessel upper heads, their penetration nozzles, and associated partial 
penetration welds are necessary for adequate protection of public 
health and safety and that the requirements of ASME BPV Code Case N 
729-6, as conditioned, represent an acceptable approach, developed, in 
part, by a voluntary consensus standards organization for performing 
future inspections. The NRC conditions on Code Case N-729-6 address 
newly defined provisions by the Code for peening and inspection relief 
for upper heads with Alloy 690 penetration nozzles which provide 
alternatives to the use of current requirements and provide 
clarification or relaxation of existing conditions. Therefore, the NRC 
concludes the incorporation by reference of ASME BPV Code Case N-729-6, 
as conditioned, into Sec.  50.55a is not a backfit.
    16. Revise Sec.  50.55a(g)(6)(ii)(F), ``Examination requirements 
for Class 1 piping and nozzle dissimilar metal butt welds.'' On 
November 7, 2016, the ASME approved the fifth revision of ASME BPV Code 
Case N-770 (N-770-5). The NRC is updating the requirements of Sec.  
50.55a(g)(6)(ii)(F) to require licensees to implement ASME BPV Code 
Case N-770-5, with conditions. The ASME BPV Code Case N-770-5 contains 
similar baseline and ISI requirements for unmitigated nickel-alloy butt 
welds, and preservice and ISI requirements for mitigated butt welds as 
N-770-2. However, N-770-5 also contains new provisions which extend the 
inspection frequency for cold leg temperature dissimilar metal butt 
welds greater than 14-inches in diameter to once per interval not to 
exceed 13 years, define performance criteria and examinations for welds 
mitigated by peening, and criteria for inservice inspection 
requirements for excavate and weld repair PWSCC mitigations. Minor 
changes were also made to address editorial issues, to correct figures, 
or to add clarity. The NRC's conditions on the use of ASME BPV Code 
Case N-770-5 have been modified to address the changes in the code 
case, clarify reporting requirements and address the implementation of 
peening and excavate and weld repair PWSCC mitigation techniques.
    The current regulatory requirements for the examination of ASME 
Class 1 piping and nozzle dissimilar metal butt welds that use nickel-
alloy materials are provided in Sec.  50.55a(g)(6)(ii)(F). This section 
was first created by rulemaking, dated June 21, 2011 (76 FR 36232), to 
require licensees to implement ASME BPV Code Case N-770-1, with 
conditions. The NRC added Sec.  50.55a(g)(6)(ii)(F) to require 
licensees to implement ASME BPV Code Case N-770-1, with conditions, 
instead of the examinations previously required by the ASME BPV Code, 
Section XI. The action did constitute a backfit; however, the NRC 
concluded that imposition of ASME BPV Code Case N-770-1, as 
conditioned, constituted an adequate protection backfit.
    The GDC for nuclear power plants (appendix A to 10 CFR part 50) or, 
as

[[Page 26571]]

appropriate, similar requirements in the licensing basis for a reactor 
facility, provide bases and requirements for NRC assessment of the 
potential for, and consequences of, degradation of the RCPB. The 
applicable GDC include GDC 14 (Reactor Coolant Pressure Boundary), GDC 
31 (Fracture Prevention of Reactor Coolant Pressure Boundary) and GDC 
32 (Inspection of Reactor Coolant Pressure Boundary). General Design 
Criterion 14 specifies that the RCPB be designed, fabricated, erected, 
and tested so as to have an extremely low probability of abnormal 
leakage, of rapidly propagating failure, and of gross rupture. General 
Design Criterion 31 specifies that the probability of rapidly 
propagating fracture of the RCPB be minimized. General Design Criterion 
32 specifies that components that are part of the RCPB have the 
capability of being periodically inspected to assess their structural 
and leaktight integrity.
    The NRC concludes that incorporation by reference of Code Case N-
770-5, as conditioned, into Sec.  50.55a as a mandatory requirement 
will continue to ensure reasonable assurance of adequate protection of 
public health and safety. Updating the regulations to require using 
ASME BPV Code Case N-770-5, with conditions, ensures leakage would 
likely not occur and potential flaws will be detected before they 
challenge the structural or leaktight integrity of these reactor 
coolant pressure boundary piping welds. All current licensees of U.S. 
pressurized water reactors will be required to implement ASME BPV Code 
Case N-770-5, as conditioned. The Code Case N-770-5 provisions for the 
examination requirements for ASME Class 1 piping and nozzle nickel-
alloy dissimilar metal butt welds are similar to those established 
under ASME BPV Code Case N-770-2, as conditioned; however, Code Case N-
770-5 includes provisions for two additional PWSCC mitigation 
techniques (peening and excavate and weld repair) along with 
requirements for performance of these techniques and examination of 
welds mitigated using them. Additionally, Code Case N-770-5 would allow 
for some relaxation in the reexamination or deferral of certain welds. 
However, the NRC's condition would not allow this relaxation/deferral 
of examination requirements. The NRC conditions on Code Case N-770-5 
address newly defined provisions by the Code for examinations and 
performance criteria for mitigation by peening, examinations for 
mitigation by excavate and weld repair, and extension of the 
examination frequency for certain cold leg temperature welds, which 
provide alternatives to the use of current requirements and provide 
clarification or relaxation of existing conditions. Therefore, the NRC 
concludes the incorporation by reference of ASME BPV Code Case N-770-5, 
as conditioned, into Sec.  50.55a is not a backfit.

ASME OM Code

    1. Revise the introductory text of paragraph (b)(3) to reference 
the 1995 Edition through the latest edition and addenda of the ASME OM 
Code incorporated by reference in Sec.  50.55a(a)(1)(iv), and to 
include Appendix IV of the ASME OM Code in the list of mandatory 
appendices incorporated by reference in Sec.  50.55a. The revision of 
Sec.  50.55a to incorporate by reference updated editions of the ASME 
OM Code is consistent with longstanding NRC policy and does not 
constitute a backfit.
    2. Revise Sec.  50.55a(b)(3)(ii) to specify that the condition on 
MOV testing applies to the latest edition and addenda of the ASME OM 
Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This will 
allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(ii). This is an administrative change to 
simplify future rulemakings and, therefore, is not a backfit.
    3. Revise Sec.  50.55a(b)(3)(iv) to (1) accept the use of Appendix 
II in the 2017 Edition of the ASME OM Code without conditions; (2) 
update Sec.  50.55a(b)(3)(iv) to apply Table II to Appendix II of the 
ASME OM Code, 2003 Addenda through the 2015 Edition; and (3) remove the 
outdated conditions in paragraphs (A) through (D) of Sec.  
50.55a(b)(3)(iv). These changes reflect improvements to Appendix II in 
the 2017 Edition of the ASME OM Code, and the removal of outdated 
conditions on previous editions and addenda of the ASME OM Code. The 
relaxation of conditions in Sec.  50.55a(b)(3)(iv) to reflect the 
updated ASME OM Code is not a backfit.
    4. Revise Sec.  50.55a(b)(3)(viii) to specify that the condition on 
Subsection ISTE applies to the latest edition and addenda of the ASME 
OM Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This will 
allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(viii). This is an administrative change to 
simplify future rulemakings and, therefore, is not a backfit.
    5. Revise Sec.  50.55a(b)(3)(ix) to specify that Subsection ISTF of 
the ASME OM Code, 2017 Edition, is acceptable without conditions, and 
that licensees applying Subsection ISTF in the 2015 Edition of the ASME 
OM Code shall satisfy the requirements of Appendix V of the ASME OM 
Code. Subsection ISTF in the 2017 Edition of the ASME OM Code has 
incorporated the provisions from Appendix V such that its reference to 
Subsection ISTF in the 2017 Edition of the ASME OM Code is not 
necessary. This is an update to the condition to apply to the 2015 
Edition (in addition to the 2012 Edition), and a relaxation to remove 
the applicability of the condition to the 2017 Edition of the ASME OM 
Code. Therefore, the update to this condition is not a backfit.
    6. Revise Sec.  50.55a(b)(3)(xi) for the implementation of 
paragraph ISTC-3700 on valve position indication in the ASME OM Code to 
apply to the 2012 Edition through the latest edition and addenda of the 
ASME OM Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This 
will allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(xi). In addition, the NRC is clarifying that 
this condition applies to all valves with remote position indicators 
within the scope of Subsection ISTC and all mandatory appendices. The 
clarification allows additional flexibility in its implementation. This 
is an administrative change to simplify future rulemakings and clarify 
and relax the condition and, therefore, is not a backfit.
    7. Revise Sec.  50.55a(f)(4)(i) and (ii) to relax the time schedule 
for complying with the latest edition and addenda of the ASME OM Code 
for the initial and successive IST programs from 12 months to 18 
months. This relaxation of the time schedule for the IST programs is 
not a backfit.
    8. Revise Sec.  50.55a(g)(4)(i) and (ii) to clarify the paragraphs 
and relax the time schedule for complying with the latest edition and 
addenda of the ASME BPV Code for the initial and successive ISI 
programs from 12 months to 18 months. This relaxation of the time 
schedule for the ISI programs is not a backfit.

Conclusion

    The NRC finds that incorporation by reference into Sec.  50.55a of 
the 2015 and 2017 Editions of Section III, Division 1, of the ASME BPV 
Code subject to the identified conditions; the 2015 and 2017 Edition of 
Section XI, Division 1, of the ASME BPV Code, subject to the identified 
conditions; the 2015 and 2017 Editions of the ASME OM Code subject

[[Page 26572]]

to the identified conditions; and the two Code Cases N-729-6 and N-770-
5 subject to identified conditions, does not constitute backfitting or 
represent an inconsistency with any issue finality provisions in 10 CFR 
part 52.

X. Plain Writing

    The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal 
agencies to write documents in a clear, concise, and well-organized 
manner. The NRC has written this document to be consistent with the 
Plain Writing Act as well as the Presidential Memorandum, ``Plain 
Language in Government Writing,'' published June 10, 1998 (63 FR 
31883).

XI. Environmental Assessment and Final Finding of No Significant 
Environmental Impact

    This final rule action is in accordance with the NRC's policy to 
incorporate by reference in Sec.  50.55a new editions and addenda of 
the ASME BPV and OM Codes to provide updated rules for constructing and 
inspecting components and testing pumps, valves, and dynamic restraints 
(snubbers) in light-water nuclear power plants. The ASME Codes are 
national voluntary consensus standards and are required by the NTTAA to 
be used by government agencies unless the use of such a standard is 
inconsistent with applicable law or otherwise impractical. The National 
Environmental Policy Act (NEPA) requires Federal agencies to study the 
impacts of their ``major Federal actions significantly affecting the 
quality of the human environment,'' and prepare detailed statements on 
the environmental impacts of the proposed action and alternatives to 
the proposed action (42 U.S.C. 4332(C); NEPA Sec. 102(C)).
    The NRC has determined under NEPA, as amended, and the NRC's 
regulations in subpart A of 10 CFR part 51, that this rule is not a 
major Federal action significantly affecting the quality of the human 
environment and, therefore, an environmental impact statement is not 
required. The rulemaking does not significantly increase the 
probability or consequences of accidents, no changes are being made in 
the types of effluents that may be released off-site, and there is no 
significant increase in public radiation exposure. The NRC concludes 
that the increase in occupational exposure would not be significant. 
This rule does not involve non-radiological plant effluents and has no 
other environmental impact. Therefore, no significant non-radiological 
impacts are associated with this action. The determination of this 
environmental assessment is that there will be no significant off-site 
impact to the public from this action.

XII. Paperwork Reduction Act Statement

    This final rule contains new or amended collections of information 
subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq). 
The collections of information were approved by the Office of 
Management and Budget (OMB), approval number 3150-0011.
    Because the rule will reduce the burden for existing information 
collections, the burden to the public for the information collections 
is estimated to be decreased by 313 hours per response. This reduction 
includes the time for reviewing instructions, searching existing data 
sources, gathering and maintaining the data needed, and completing and 
reviewing the information collection.
    The information collection is being conducted to document the plans 
for and the results of ISI and IST programs. The records are generally 
historical in nature and provide data on which future activities can be 
based. The practical utility of the information collection for the NRC 
is that appropriate records are available for auditing by NRC personnel 
to determine if ASME BPV and OM Code provisions for construction, 
inservice inspection, repairs, and inservice testing are being properly 
implemented in accordance with Sec.  50.55a, or whether specific 
enforcement actions are necessary. Responses to this collection of 
information are generally mandatory under Sec.  50.55a.
    You may submit comments on any aspect of the information 
collection(s), including suggestions for reducing the burden, by the 
following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2016-0082.
     Mail comments to: Information Services Branch, Office of 
the Chief Information Officer, Mail Stop: T6-A10M, U.S. Nuclear 
Regulatory Commission, Washington, DC 20555-0001 or to the OMB reviewer 
at: OMB Office of Information and Regulatory Affairs (3150-0011), Attn: 
Desk Officer for the Nuclear Regulatory Commission, 725 17th Street NW, 
Washington, DC 20503; email: [email protected].

Public Protection Notification

    The NRC may not conduct or sponsor, and a person is not required to 
respond to, a collection of information unless the document requesting 
or requiring the collection displays a currently valid OMB control 
number.

XIII. Congressional Review Act

    This final rule is a rule as defined in the Congressional Review 
Act (5 U.S.C. 801-808). However, the Office of Management and Budget 
has not found it to be a major rule as defined in the Congressional 
Review Act.

XIV. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113 (NTTAA), and implementing guidance in U.S. Office of 
Management and Budget (OMB) Circular A-119 (February 10, 1998), 
requires that Federal agencies use technical standards that are 
developed or adopted by voluntary consensus standards bodies unless 
using such a standard is inconsistent with applicable law or is 
otherwise impractical. The NTTAA requires Federal agencies to use 
industry consensus standards to the extent practical; it does not 
require Federal agencies to endorse a standard in its entirety. Neither 
the NTTAA nor Circular A-119 prohibit an agency from adopting a 
voluntary consensus standard while taking exception to specific 
portions of the standard, if those provisions are deemed to be 
``inconsistent with applicable law or otherwise impractical.'' 
Furthermore, taking specific exceptions furthers the Congressional 
intent of Federal reliance on voluntary consensus standards because it 
allows the adoption of substantial portions of consensus standards 
without the need to reject the standards in their entirety because of 
limited provisions that are not acceptable to the agency.
    In this final rule, the NRC is continuing its existing practice of 
establishing requirements for the design, construction, operation, ISI 
(examination) and IST of nuclear power plants by approving the use of 
the latest editions and addenda of the ASME BPV and OM Codes (ASME 
Codes) in Sec.  50.55a. The ASME Codes are voluntary consensus 
standards, developed by participants with broad and varied interests, 
in which all interested parties (including the NRC and licensees of 
nuclear power plants) participate. Therefore, the NRC's incorporation 
by reference of the ASME Codes is consistent with the overall 
objectives of the NTTAA and OMB Circular A-119.
    As discussed in Section II of this document, this final rule 
conditions the use of certain provisions of the 2015 and 2017 Editions 
to the ASME BPV Code, Section III, Division 1 and the ASME

[[Page 26573]]

BPV Code, Section XI, Division 1, as well as the 2015 and 2017 Editions 
to the ASME OM Code. This final rule also includes Code Cases N-729-6 
and N-770-5. The NRC is using the following voluntary consensus 
standard: ``Materials Reliability Program: Topical Report for Primary 
Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement'' (MRP-335, Revision 3-A), EPRI approval date: November 
2016. The NRC is incorporating this standard because the NRC references 
MRP-335, Revision 3-A, within this condition on the requirements in the 
ASME Code Cases. In addition, the NRC is proposing to not adopt 
(``excludes'') certain provisions of the ASME Codes and MRP-335, 
Revision 3-A, as discussed in this document, and in the regulatory and 
backfit analysis for this final rule. The NRC determines that this 
final rule complies with the NTTAA and OMB Circular A-119 despite these 
conditions and ``exclusions.''
    If the NRC did not conditionally accept ASME editions, addenda, and 
code cases, the NRC would disapprove them entirely. The effect would be 
that licensees and applicants would submit a larger number of requests 
for the use of alternatives under Sec.  50.55a(z), requests for relief 
under Sec.  50.55a(f) and (g), or requests for exemptions under Sec.  
50.12 and/or Sec.  52.7. These requests would likely include broad-
scope requests for approval to issue the full scope of the ASME Code 
editions and addenda which would otherwise be approved in this final 
rule (i.e., the request would not be simply for approval of a specific 
ASME Code provision with conditions). These requests would be an 
unnecessary additional burden for both the licensee and the NRC, since 
the NRC has already determined that the ASME Codes and Code Cases that 
are the subject of this final rule are acceptable for use (in some 
cases with conditions). For these reasons, the NRC concludes that this 
final rule's treatment of ASME Code editions and addenda, and code 
cases and any conditions placed on them does not conflict with any 
policy on agency use of consensus standards specified in OMB Circular 
A-119.
    The NRC did not identify any other voluntary consensus standards 
developed by U.S. voluntary consensus standards bodies for use within 
the U.S. that the NRC could incorporate by reference instead of the 
ASME Codes. The NRC also did not identify any voluntary consensus 
standards developed by multinational voluntary consensus standards 
bodies for use on a multinational basis that the NRC could incorporate 
by reference instead of the ASME Codes. The NRC identified codes 
addressing the same subject as the ASME Codes for use in individual 
countries. At least one country, Korea, directly translated the ASME 
Code for use in that country. In other countries (e.g., Japan), ASME 
Codes were the basis for development of the country's codes, but the 
ASME Codes were substantially modified to accommodate that country's 
regulatory system and reactor designs. Finally, there are countries 
(e.g., the Russian Federation) where that country's code was developed 
without regard to the ASME Code. However, some of these codes may not 
meet the definition of a voluntary consensus standard because they were 
developed by the state rather than a voluntary consensus standards 
body. Evaluation by the NRC of the countries' codes to determine 
whether each code provides a comparable or enhanced level of safety 
when compared against the level of safety provided under the ASME Codes 
would require a significant expenditure of agency resources. This 
expenditure does not seem justified, given that substituting another 
country's code for the U.S. voluntary consensus standard does not 
appear to substantially further the apparent underlying objectives of 
the NTTAA.
    In summary, this final rule satisfies the requirements of the NTTAA 
and OMB Circular A-119.

XV. Incorporation by Reference--Reasonable Availability to Interested 
Parties

    The NRC is incorporating by reference four recent editions to the 
ASME Codes for nuclear power plants (2015 ASME Boiler and Pressure 
Vessel Code, 2017 ASME Boiler and Pressure Vessel Code, ASME OM-2015, 
and ASME OM-2017) and two revised ASME Code Cases (ASME BPV Code Case 
N-729-6 and ASME BPV Code Case N-770-5). As described in the 
``Background'' and ``Discussion'' sections of this document, these 
materials contain standards for the design, fabrication, and inspection 
of nuclear power plant components. The NRC is also incorporating by 
reference an EPRI Topical Report. As described in the ``Background'' 
and ``Discussion'' sections of this document, this report contains 
requirements related to the two revised ASME Code Cases.
    The NRC is required by law to obtain approval for incorporation by 
reference from the Office of the Federal Register (OFR). The OFR's 
requirements for incorporation by reference are set forth in 1 CFR part 
51. On November 7, 2014, the OFR adopted changes to its regulations 
governing incorporation by reference (79 FR 66267). The OFR regulations 
require an agency to include in a final rule a discussion of the ways 
that the materials the agency incorporates by reference are reasonably 
available to interested parties or how it worked to make those 
materials reasonably available to interested parties. The discussion in 
this section complies with the requirement for final rules as set forth 
in Sec.  51.5(b).
    The NRC considers ``interested parties'' to include all potential 
NRC stakeholders, not only the individuals and entities regulated or 
otherwise subject to the NRC's regulatory oversight. These NRC 
stakeholders are not a homogenous group but vary with respect to the 
considerations for determining reasonable availability. Therefore, the 
NRC distinguishes between different classes of interested parties for 
the purposes of determining whether the material is ``reasonably 
available.'' The NRC considers the following to be classes of 
interested parties in NRC rulemakings with regard to the material to be 
incorporated by reference:
     Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight (this class also includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals) and who are subject to the material to be 
incorporated by reference by rulemaking. In this context, ``small 
entities'' has the same meaning as a ``small entity'' under Sec.  
2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight (this class also includes applicants and potential applicants 
for licenses and other NRC regulatory approvals) and who are subject to 
the material to be incorporated by reference by rulemaking. In this 
context, ``large entities'' are those which do not qualify as a ``small 
entity'' under Sec.  2.810.
     Non-governmental organizations with institutional 
interests in the matters regulated by the NRC.
     Other Federal agencies, states, local governmental bodies 
(within the meaning of Sec.  2.315(c)).
     Federally-recognized and State-recognized \5\ Indian 
tribes.
---------------------------------------------------------------------------

    \5\ State-recognized Indian tribes are not within the scope of 
Sec.  2.315(c). However, for purposes of the NRC's compliance with 1 
CFR 51.5, ``interested parties'' includes a broad set of 
stakeholders, including State-recognized Indian tribes.
---------------------------------------------------------------------------

     Members of the general public (i.e., individual, 
unaffiliated members of the public who are not regulated or otherwise 
subject to the NRC's regulatory oversight) who may wish to gain access 
to the materials which the

[[Page 26574]]

NRC proposes to incorporate by reference by rulemaking in order to 
participate in the rulemaking process.
    The NRC makes the materials to be incorporated by reference 
available for inspection to all interested parties, by appointment, at 
the NRC Technical Library, which is located at Two White Flint North, 
11545 Rockville Pike, Rockville, Maryland 20852; telephone: 301-415-
7000; email: [email protected].
    Interested parties may obtain a copy of the EPRI Topical Report 
free of charge from EPRI from their website at https://www.epri.com.
    Interested parties may purchase a copy of the ASME materials from 
ASME at Three Park Avenue, New York, NY 10016, or at the ASME website 
https://www.asme.org/shop/standards. The materials are also accessible 
through third-party subscription services such as IHS (15 Inverness Way 
East, Englewood, CO 80112; https://global.ihs.com) and Thomson Reuters 
Techstreet (3916 Ranchero Dr., Ann Arbor, MI 48108; https://www.techstreet.com). The purchase prices for individual documents range 
from $225 to $720 and the cost to purchase all documents is 
approximately $9,000.
    For the class of interested parties constituting members of the 
general public who wish to gain access to the materials to be 
incorporated by reference in order to participate in the rulemaking, 
the NRC recognizes that the $9,000 cost may be so high that the 
materials could be regarded as not reasonably available for purposes of 
commenting on this final rule, despite the NRC's actions to make the 
materials available at the NRC's PDR.
    Accordingly, the NRC sent a letter to the ASME requesting that they 
consider enhancing public access to these materials during the public 
comment period (ADAMS Accession No. ML17310A186). In a May 30, 2018, 
email to the NRC, the ASME agreed to make the materials available 
online in a read-only electronic access format during the public 
comment period (ADAMS Accession No. ML18157A113).
    During the public comment period, the ASME made publicly-available 
the four editions to the ASME Codes for nuclear power plants and the 
two ASME Code Cases which the NRC proposed to incorporate by reference. 
The ASME made the materials publicly-available in read-only format at 
the ASME website https://go.asme.org/NRC-ASME.
    The materials are available to all interested parties in multiple 
ways and in a manner consistent with their interest in this final rule. 
Therefore, the NRC concludes that the materials the NRC is 
incorporating by reference in this final rule are reasonably available 
to all interested parties.

XVI. Availability of Guidance

    The NRC will not be issuing guidance for this final rule. The ASME 
BPV Code and OM Code provide direction for the performance of 
activities to satisfy the Code requirements for design, inservice 
inspection, and inservice testing of nuclear power plant SSCs. In 
addition, the NRC provides guidance in this Federal Register notice for 
the implementation of the new conditions on the ASME BPV Code and OM 
Code, as necessary. The NRC has a number of standard review plans 
(SRPs), which provide guidance to NRC reviewers and make communication 
and understanding of NRC review processes available to members of the 
public and the nuclear power industry. NUREG-0800, ``Review of Safety 
Analysis Reports for Nuclear Power Plants,'' has numerous sections 
which discuss implementation of various aspects of the ASME BPV Code 
and OM Code (e.g., Sections 3.2.2, 3.8.1, 3.8.2, 3.9.3, 3.9.6, 3.9.7, 
3.9.8, 3.13, 5.2.1.1, 5.2.1.2, 5.2.4, and 6.6). The NRC also publishes 
Regulatory Guides and Generic Communications (i.e., Regulatory Issue 
Summaries, Information Notices) to communicate and clarify NRC 
technical or policy positions on regulatory matters which may contain 
guidance relative to this final rule.
    Revision 2 of NUREG-1482, ``Guidelines for Inservice Testing at 
Nuclear Power Plants,'' provides guidance for the development and 
implementation of IST programs at nuclear power plants. With direction 
provided in the ASME BPV and OM Codes, and guidance in this Federal 
Register notice, the NRC has determined that preparation of a separate 
guidance document is not necessary for this update to Sec.  50.55a. 
However, the NRC is preparing a revision to NUREG-1482 to address the 
latest edition of the ASME OM Code incorporated by reference in Sec.  
50.55a.

XVII. Availability of Documents

    The NRC is making the documents identified in Table 1 available to 
interested persons through one or more of the following methods, as 
indicated. To access documents related to this action, see the 
ADDRESSES section of this document.

                   Table 1--Availability of Documents
------------------------------------------------------------------------
                                                   ADAMS accession No./
                    Document                         Federal Register
                                                     citation/web link
------------------------------------------------------------------------
Proposed Rule Documents:
    Proposed Rule--Federal Register Notice......  83 FR 56156 (November
                                                   9, 2018).
    Draft Regulatory Analysis (includes           ML18150A267.
     backfitting discussion in Appendix A).
Final Rule Documents:
    Final Regulatory Analysis...................  ML19098A807.
    Final Rule (10 CFR 50.55a) American Society   ML19095B549.
     of Mechanical Engineers Codes and Code
     Cases: Analysis of Public Comments.
Related Documents:
    NRC Meeting Summary of July 30, 2018          ML18219B862.
     Category 3 Public Meeting to Discuss
     Rulemaking to Incorporate by Reference
     American Society of Mechanical Engineers
     Codes into NRC Regulations.
    Letter from Brian Thomas, NRC, to William     ML17310A186.
     Berger, ASME; ``Public Access to Material
     the NRC Seeks to Incorporate by Reference
     into its Regulations--Revised Request;''
     January 8, 2018.
    Email from Christian Sanna, ASME, to Brian    ML18157A113.
     Thomas, NRC; May 30, 2018.
    Memorandum from Wallace Norris, NRC, to       ML14245A003.
     David Rudland, NRC; ``Summary of August 22,
     2014, Public Meeting Between ASME and NRC--
     Information Exchange''; September 8, 2014.
    Letter from John Lubinski, NRC, to Kevin      ML14261A051.
     Ennis, ASME; ``NRC Information Notice 2014-
     07 Regarding Inspection of Containment Leak-
     Chase Channels''; March 3, 2015.
    Letter from Ralph Hill, ASME, to John         ML15106A627.
     Lubinski, NRC; ``ASME Code, Section XI
     Actions to Address Requirements for
     Examination of Containment Leak-Chase
     Channels;'' April 13, 2015.

[[Page 26575]]

 
    NRC Staff Requirements Memorandum SRM-        ML003755050.
     M990910, ``Staff Requirements--Affirmation
     Session, 11:30 a.m., Friday, September 10,
     1999, Commissioners' Conference Room, One
     White Flint North, Rockville, Maryland
     (Open to Public Attendance),'' September
     10, 1999.
    NUREG/CR-6654, ``A Study of Air-Operated      ML003691872.
     Valves in U.S. Nuclear Power Plants,''
     February 2000.
    NRC Generic Letter 88-14, ``Instrument Air    ML031130440.
     Supply System Problems Affecting Safety-
     Related Equipment,'' August 1988.
    NRC Regulatory Issue Summary 2000-03,         ML003686003.
     ``Resolution of Generic Safety Issue (GSI)
     158, `Performance of Safety Related Power-
     Operated Valves Under Design-Basis
     Conditions','' March 2000.
    NRC Information Notice 1986-050,              ML031220684.
     ``Inadequate Testing to Detect Failures of
     Safety-Related Pneumatic Components or
     Systems''; June 1986.
    NRC Information Notice 1985-084,              ML031180213.
     ``Inadequate Inservice Testing of Main
     Steam Isolation Valves,'' October 1985.
    NRC Information Notice 1996-048, ``Motor-     ML031060093.
     Operated Valve Performance Issues,'' August
     1996.
    NRC Information Notice 1996-048, Supplement   ML031050431.
     1, ``Motor-Operated Valve Performance
     Issues,'' July 1998.
    NRC Information Notice 1998-13, ``Post-       ML031050237.
     Refueling Outage Reactor Pressure Vessel
     Leakage Testing Before Core Criticality,''
     April 1998.
    NRC Information Notice 2014-07,               ML14070A114.
     ``Degradation of Leak-Chase Channel Systems
     for Floor Welds of Metal Containment Shell
     and Concrete Containment Metallic Liner,''
     May 2014.
    NRC Information Notice 2015-13, ``Main Steam  ML15252A122.
     Isolation Valve Failure Events,'' December
     2015.
    NRC Inspection Report 50-254/97027, March     ML15216A276.
     1998.
    NUREG-0800, Section 5.4.2.2, Revision 1,      ML052340627.
     ``Steam Generator Tube Inservice
     Inspection,'' July 1981.
    NUREG-0800, Section 5.4.2.2, Revision 2,      ML070380194.
     ``Steam Generator Program,'' March 2007.
    NRC Regulatory Guide 1.83, Revision 1,        ML003740256.
     ``Inservice Inspection of Pressurized Water
     Reactor Steam Generator Tubes,'' July 1975
     (withdrawn in 2009).
    RG 1.147, ``Inservice Inspection Code Case    ML19128A244.
     Acceptability, ASME Section XI, Division
     1,'' Revision 19.
    NUREG/CR-7153, ``Expanded Materials           ML14279A321.
     Degradation Assessment (EMDA),'' October     ML14279A461.
     2014.                                        ML14279A349.
                                                  ML14279A430.
                                                  ML14279A331.
    NUREG-0619, Rev. 1, ``BWR Feedwater Nozzle    ML031600712.
     and Control Rod Drive Return Line Nozzle
     Cracking: Resolution of Generic Technical
     Activity A-10 (Technical Report),''
     November 1980.
    NUREG-1801, Rev. 2, ``Generic Aging Lessons   ML103490041.
     Learned (GALL) Report,'' December 2010.
    NUREG-1800, Rev. 2, ``Standard Review Plan    ML103490036.
     for Review of License Renewal Applications
     for Nuclear Power Plants,'' December 2010.
    NUREG-2191, ``Generic Aging Lessons Learned   ML17187A031.
     for Subsequent License Renewal (GALL-SLR)    ML17187A204.
     Report,'' July 2017.
    NUREG-1950, ``Disposition of Public Comments  ML11116A062.
     and Technical Bases for Changes in the
     License Renewal Guidance Documents NUREG-
     1801 and NUREG-1800,'' April 2011.
    NUREG/CR-6933, ``Assessment of Crack          ML071020410.
     Detection in Heavy-Walled Cast Stainless     ML071020414.
     Steel Piping Welds Using Advanced Low-
     Frequency Ultrasonic Methods,'' March 2007.
    NUREG/CR-7122, ``An Evaluation of Ultrasonic  ML12087A004.
     Phased Array Testing for Cast Austenitic
     Stainless Steel Pressurizer Surge Line
     Piping Welds,'' March 2012.
    NUREG-2192, ``Standard Review Plan for        ML17188A158.
     Review of Subsequent License Renewal
     Applications for Nuclear Power Plants,''
     July 2017.
    Gupta KK, Hoffmann CL, Hamilton AM, DeLose    https://
     F. Fracture Toughness of Pressure Boundary    proceedings.asmedigit
     Steels With Higher Yield Strength. ASME.      alcollection.asme.org/
     ASME Pressure Vessels and Piping              proceeding.aspx?artic
     Conference, ASME 2010 Pressure Vessels and    leid=1619041.
     Piping Conference: Volume 7 ():45-58.
     doi:10.1115/PVP2010-25214.
------------------------------------------------------------------------

List of Subjects in 10 CFR Part 50

    Administrative practice and procedure, Antitrust, Backfitting, 
Classified information, Criminal penalties, Education, Fire prevention, 
Fire protection, Incorporation by reference, Intergovernmental 
relations, Nuclear power plants and reactors, Penalties, Radiation 
protection, Reactor siting criteria, Reporting and recordkeeping 
requirements, Whistleblowing.

    For the reasons set forth in the preamble, and under the authority 
of the Atomic Energy Act of 1954, as amended; the Energy Reorganization 
Act of 1974, as amended; and 5 U.S.C. 552 and 553, the NRC is adopting 
the following amendments to 10 CFR part 50:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

0
1. The authority citation for part 50 continues to read as follows:

    Authority: Atomic Energy Act of 1954, secs. 11, 101, 102, 103, 
104, 105, 108, 122, 147, 149, 161, 181, 182, 183, 184, 185, 186, 
187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132, 2133, 2134, 2135, 
2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236, 
2237, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs. 
201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); Nuclear Waste 
Policy Act of 1982, sec. 306 (42 U.S.C. 10226); National 
Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504 
note; Sec. 109, Public Law 96-295, 94 Stat. 783.


[[Page 26576]]



0
2. In Sec.  50.55a:
0
a. In paragraph (a)(1)(i), remove the phrase ``(referred to herein as 
ASME BPV Code)'';
0
b. In paragraph (a)(1)(i)(E)(16), remove the word ``and'';
0
c. In paragraph (a)(1)(i)(E)(17), at the end of the sentence, remove 
the period and add in its place a comma;
0
d. Add paragraphs (a)(1)(i)(E)(18) and (19);
0
e. In paragraph (a)(1)(ii) introductory text, remove ``BPV Code'' and 
add in its place ``Boiler and Pressure Vessel Code'';
0
f. Revise paragraphs (a)(1)(ii)(C)(52) and (53);
0
g. Add paragraphs (a)(1)(ii)(C)(54) and (55);
0
h. Revise paragraphs (a)(1)(iii)(C) and (D);
0
i. In paragraph (a)(1)(iv) introductory text, remove the phrase 
``(various edition titles referred to herein as ASME OM Code)'';
0
j. Revise paragraph (a)(1)(iv)(C)(1);
0
k. In paragraphs (a)(3)(i) through (iii), wherever it appears remove 
the phrase ``March 2017'' and add in its place the phrase ``October 
2019'';
0
l. Add paragraph (a)(4);
0
m. In paragraph (b)(1) introductory text, remove the number ``2013'' 
and add in its place the number ``2017'';
0
n. In paragraph (b)(1)(ii), in Table I, remove the number ``2013'' in 
the last entry in the ``Editions and addenda'' column and add in its 
place the number ``2017'', and remove the word ``Note'' wherever it 
appears in the ``Code provision'' column and add in its place the word 
``Footnote'';
0
o. In paragraph (b)(1)(iii) introductory text, remove the phrase ``2008 
Addenda'' wherever it appears and add in its place the phrase ``2017 
Edition'';
0
p. Revise paragraph (b)(1)(v);
0
q. In paragraph (b)(1)(vi), remove the phrase ``the latest edition and 
addenda'' and add in its place the phrase ``all editions and addenda up 
to and including the 2013 Edition'';
0
r. In paragraph (b)(1)(vii), remove the phrase ``the 2013 Edition'' and 
add in its place the phrase ``all editions and addenda up to and 
including the 2017 Edition'';
0
s. Add paragraphs (b)(1)(x) through (xii);
0
t. In paragraph (b)(2) introductory text, remove the number ``2013'' 
and add in its place the number ``2017'';
0
u. Remove and reserve paragraphs (b)(2)(vi) and (vii);
0
v. Revise paragraph (b)(2)(ix) introductory text;
0
w. Add paragraph (b)(2)(ix)(K);
0
x. Remove and reserve paragraph (b)(2)(xvii);
0
y. In paragraph (b)(2)(xviii)(D), remove the phrase ``and 2013 Edition 
of Section XI of the ASME BPV Code'' and add in its place the phrase 
``through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section'';
0
z. Revise paragraph (b)(2)(xx)(B);
0
aa. Add paragraph (b)(2)(xx)(C);
0
bb. Remove and reserve paragraph (b)(2)(xxi)(A);
0
cc. Add paragraph (b)(2)(xxi)(B);
0
dd. Revise paragraphs (b)(2)(xxv), (xxvi), and (xxxii) and 
(b)(2)(xxxiv) introductory text;
0
ee. In paragraph (b)(2)(xxxiv)(B) add the phrase ``of the 2013 and the 
2015 Editions'' after the phrase ``Appendix U'';
0
ff. Revise paragraph (b)(2)(xxxv);
0
gg. In paragraph (b)(2)(xxxvi), remove the word ``Edition'' and add in 
its place the phrase ``through 2017 Editions'';
0
hh. Add paragraphs (b)(2)(xxxviii) through (xlii);
0
ii. In paragraph (b)(3) introductory text, add ``IV,'' after ``III,'', 
remove the phrase ``2012 Edition, as specified'' and add in its place 
the phrase ``latest edition and addenda of the ASME OM Code 
incorporated by reference'' and revise the last sentence in the 
paragraph;
0
jj. In paragraph (b)(3)(ii) introductory text, remove the phrase ``, 
2011 Addenda, and 2012 Edition'' and add in its place the phrase 
``through the latest edition and addenda of the ASME OM Code 
incorporated by reference in paragraph (a)(1)(iv) of this section'';
0
kk. Revise paragraph (b)(3)(iv) introductory text;
0
ll. Remove paragraphs (b)(3)(iv)(A) through (D);
0
mm. In paragraph (b)(3)(viii), remove the phrase ``, 2011 Addenda, or 
2012 Edition'' and add in its place the phrase ``through the latest 
edition and addenda of the ASME OM Code incorporated by reference in 
paragraph (a)(1)(iv) of this section'';
0
nn. Revise paragraphs (b)(3)(ix) and (xi);
0
oo. In paragraphs (f)(4)(i) and (ii), remove the number ``12'' wherever 
it appears and add in its place the number ``18'';
0
pp. In paragraph (g)(4) introductory text, remove the phrase ``, 
subject to the condition listed in paragraph (b)(2)(vi) of this 
section'';
0
qq. In paragraph (g)(4)(i), remove the number ``12'' wherever it 
appears and add in its place the number ``18'', and revise the last 
sentence;
0
rr. In paragraph (g)(4)(ii), in the first sentence, remove the number 
``12'' and add in its place the number ``18''; remove the date ``August 
17, 2017'' wherever it appears and add in its place ``June 3, 2020'', 
and revise the last sentence;
0
ss. Remove and reserve paragraph (g)(6)(ii)(C);
0
tt. Revise paragraphs (g)(6)(ii)(D)(1), (2) and (4);
0
uu. Add paragraphs (g)(6)(ii)(D)(5) through (8);
0
vv. Revise paragraphs (g)(6)(ii)(F)(1) and (2);
0
ww. Remove and reserve paragraph (g)(6)(ii)(F)(3);
0
xx. Revise paragraphs (g)(6)(ii)(F)(4), (6), (9), and (10);
0
yy. Remove and reserve paragraph (g)(6)(ii)(F)(11);
0
zz. Revise paragraph (g)(6)(ii)(F)(13); and
0
aaa. Add paragraphs (g)(6)(ii)(F)(14) through (16).
    The revisions and additions read as follows:


Sec.  50.55a  Codes and standards.

    (a) * * *
    (1) * * *
    (i) * * *
    (E) * * *
    (18) 2015 Edition (including Subsection NCA; and Division 1 
subsections NB through NH and Appendices), and
    (19) 2017 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices).
* * * * *
    (ii) * * *
    (C) * * *
    (52) 2011a Addenda,
    (53) 2013 Edition,
    (54) 2015 Edition, and
    (55) 2017 Edition.
* * * * *
    (iii) * * *
    (C) ASME BPV Code Case N-729-6. ASME BPV Code Case N-729-6, 
``Alternative Examination Requirements for PWR Reactor Vessel Upper 
Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds 
Section XI, Division 1'' (Approval Date: March 3, 2016), with the 
conditions in paragraph (g)(6)(ii)(D) of this section.
    (D) ASME BPV Code Case N-770-5. ASME BPV Code Case N-770-5, 
``Alternative Examination Requirements and Acceptance Standards for 
Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS 
N06082 or UNS W86182 Weld Filler Material With or Without Application 
of Listed Mitigation Activities Section XI, Division 1'' (Approval 
Date: November 7, 2016), with the conditions in paragraph (g)(6)(ii)(F) 
of this section.
* * * * *
    (iv) * * *

[[Page 26577]]

    (C) Operation and Maintenance of Nuclear Power Plants:
    (1) 2012 Edition, ``Division 1: OM Code: Section IST''
    (2) 2015 Edition, and
    (3) 2017 Edition.
* * * * *
    (4) Electric Power Research Institute, Materials Reliability 
Program, 3420 Hillview Avenue, Palo Alto, CA 94304-1338; telephone: 1-
650-855-2000; https://www.epri.com.
    (i) ``Materials Reliability Program: Topical Report for Primary 
Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement (MRP-335, Revision 3-A)'', EPRI approval date: November 
2016.
    (ii) [Reserved]
* * * * *
    (b) * * *
    (1) * * *
    (v) Section III condition: Independence of inspection. Applicants 
or licensees may not apply the exception in NCA-4134.10(a) of Section 
III, 1995 Edition through 2009b Addenda of the 2007 Edition, from 
paragraph 3.1 of Supplement 10S-1 of NQA-1-1994 Edition.
* * * * *
    (x) Section III Condition: Visual examination of bolts, studs and 
nuts. Applicants or licensees applying the provisions of NB-2582, NC-
2582, ND-2582, NE-2582, NF-2582, NG-2582 in the 2017 Edition of Section 
III, must apply paragraphs (b)(1)(x)(A) through (B) of this section.
    (A) Visual examination of bolts, studs, and nuts: First provision. 
When applying the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, NG-2582 in the 2017 Edition of Section III, the visual 
examinations are required to be performed in accordance with procedures 
qualified to NB-5100, NC-5100, ND-5100, NE-5100, NF-5100, NG-5100 and 
performed by personnel qualified in accordance with NB-5500, NC-5500, 
ND-5500, NE-5500, NF-5500, and NG-5500.
    (B) Visual examination of bolts, studs, and nuts: Second provision. 
When applying the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, and NG-2582 in the 2017 Edition of Section III, bolts, studs, and 
nuts must be visually examined for discontinuities including cracks, 
bursts, seams, folds, thread lap, voids, and tool marks.
    (xi) Section III condition: Mandatory Appendix XXVI. When applying 
the 2015 and 2017 Editions of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the following conditions:
    (A) Mandatory Appendix XXVI: First provision. When performing 
fusing procedure qualification testing in accordance with XXVI-2300 and 
XXVI-4330 the following essential variables must be used for the 
performance qualification tests of butt fusion joints:
    (1) Joint Type: A change in the type of joint from that qualified, 
except that a square butt joint qualifies as a mitered joint.
    (2) Pipe Surface Alignment: A change in the pipe outside diameter 
(O.D.) surface misalignment of more than 10 percent of the wall 
thickness of the thinner member to be fused.
    (3) PE Material: Each lot of polyethylene source material to be 
used in production (XXVI-2310(c)).
    (4) Wall Thickness: Each thickness to be fused in production (XXVI-
2310(c)).
    (5) Diameter: Each diameter to be fused in production (XXVI-
2310(c)).
    (6) Cross-sectional Area: Each combination of thickness and 
diameter (XXVI-2310(c)).
    (7) Position: Maximum machine carriage slope when greater than 20 
degrees from horizontal (XXVI-4321(c)).
    (8) Heater Surface Temperature: A change in the heater surface 
temperature to a value beyond the range tested (XXVI-2321).
    (9) Ambient Temperature: A change in ambient temperature to less 
than 50 [deg]F (10 [deg]C) or greater than 125 [deg]F (52 [deg]C) 
(XXVI-4412(b)).
    (10) Interfacial Pressure: A change in interfacial pressure to a 
value beyond the range tested (XXVI-2321).
    (11) Decrease in Melt Bead Width: A decrease in melt bead size from 
that qualified.
    (12) Increase in Heater Removal Time: An increase in heater plate 
removal time from that qualified.
    (13) Decrease in Cool-down Time: A decrease in the cooling time at 
pressure from that qualified.
    (14) Fusing Machine Carriage Model: A change in the fusing machine 
carriage model from that tested (XXVI-2310(d)).
    (B) Mandatory Appendix XXVI: Second provision. When performing 
procedure qualification for high speed tensile impact testing of butt 
fusion joints in accordance with XXVI-2300 or XXVI-4330, breaks in the 
specimen that are away from the fusion zone must be retested. When 
performing fusing operator qualification bend tests of butt fusion 
joints in accordance with XXVI-4342, guided side bend testing must be 
used for all thicknesses greater than 1.25 inches.
    (C) Mandatory Appendix XXVI: Third provision. When performing 
fusing procedure qualification tests in accordance with 2017 Edition of 
BPV Code Section III XXVI-2300 and XXVI-4330, the following essential 
variables must be used for the testing of electrofusion joints:
    (1) Joint Design: A change in the design of an electrofusion joint.
    (2) Fit-up Gap: An increase in the maximum radial fit-up gap 
qualified.
    (3) Pipe PE Material: A change in the PE designation or cell 
classification of the pipe from that tested (XXVI-2322(a)).
    (4) Fitting PE Material: A change in the manufacturing facility or 
production lot from that tested (XXVI-2322(b)).
    (5) Pipe Wall Thickness: Each thickness to be fused in production 
(XXVI-2310(c)).
    (6) Fitting Manufacturer: A change in fitting manufacturer.
    (7) Pipe Diameter: Each diameter to be fused in production (XXVI-
2310(c)).
    (8) Cool-down Time: A decrease in the cool time at pressure from 
that qualified.
    (9) Fusion Voltage: A change in fusion voltage.
    (10) Nominal Fusion Time: A change in the nominal fusion time.
    (11) Material Temperature Range: A change in material fusing 
temperature beyond the range qualified.
    (12) Power Supply: A change in the make or model of electrofusion 
control box (XXVI-2310(f)).
    (13) Power Cord: A change in power cord material, length, or 
diameter that reduces current at the coil to below the minimum 
qualified.
    (14) Processor: A change in the manufacturer or model number of the 
processor. (XXVI-2310(f)).
    (15) Saddle Clamp: A change in the type of saddle clamp.
    (16) Scraping Device: A change from a clean peeling scraping tool 
to any other type of tool.
    (xii) Section III condition: Certifying Engineer. When applying the 
2017 and later editions of ASME BPV Code Section III, the NRC does not 
permit applicants and licensees to use a Certifying Engineer who is not 
a Registered Professional Engineer qualified in accordance with 
paragraph XXIII-1222 for Code-related activities that are applicable to 
U.S. nuclear facilities regulated by the NRC. The use of paragraph 
XXIII-1223 is prohibited.
    (2) * * *
    (ix) Section XI condition: Metal containment examinations. 
Applicants or licensees applying Subsection IWE, 1992 Edition with the 
1992 Addenda, or the 1995 Edition with the 1996 Addenda, must satisfy 
the requirements of paragraphs (b)(2)(ix)(A) through (E)

[[Page 26578]]

and (b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 1998 Edition through the 2001 Edition with the 2003 
Addenda, must satisfy the requirements of paragraphs (b)(2)(ix)(A) and 
(B) and (b)(2)(ix)(F) through (I) and (b)(2)(ix)(K) of this section. 
Applicants or licensees applying Subsection IWE, 2004 Edition, up to 
and including the 2005 Addenda, must satisfy the requirements of 
paragraphs (b)(2)(ix)(A) and (B) and (b)(2)(ix)(F) through (H) and 
(b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 2004 Edition with the 2006 Addenda, must satisfy the 
requirements of paragraphs (b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and 
(b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 2007 Edition through the 2015 Edition, must satisfy the 
requirements of paragraphs (b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and (J) 
and (K) of this section. Applicants or licensees applying Subsection 
IWE, 2017 Edition, must satisfy the requirements of paragraphs 
(b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and (J) of this section.
* * * * *
    (K) Metal Containment Examinations: Eleventh provision. A general 
visual examination of containment leak chase channel moisture barriers 
must be performed once each interval, in accordance with the completion 
percentages in Table IWE 2411-1 of the 2017 Edition. Examination shall 
include the moisture barrier materials (caulking, gaskets, coatings, 
etc.) that prevent water from accessing the embedded containment liner 
within the leak chase channel system. Caps of stub tubes extending to 
or above the concrete floor interface may be inspected, provided the 
configuration of the cap functions as a moisture barrier as described 
previously. Leak chase channel system closures need not be disassembled 
for performance of examinations if the moisture barrier material is 
clearly visible without disassembly, or coatings are intact. The 
closures are acceptable if no damage or degradation exists that would 
allow intrusion of moisture against inaccessible surfaces of the metal 
containment shell or liner within the leak chase channel system. 
Examinations that identify flaws or relevant conditions shall be 
extended in accordance with paragraph IWE 2430 of the 2017 Edition.
    (xx) * * *
    (B) System leakage tests: Second provision. The nondestructive 
examination method and acceptance criteria of the 1992 Edition or later 
of Section III shall be met when performing system leakage tests (in 
lieu of a hydrostatic test) in accordance with IWA-4520 after repair 
and replacement activities performed by welding or brazing on a 
pressure retaining boundary using the 2003 Addenda through the latest 
edition and addenda of Section XI incorporated by reference in 
paragraph (a)(1)(ii) of this section. The nondestructive examination 
and pressure testing may be performed using procedures and personnel 
meeting the requirements of the licensee's/applicant's current ISI code 
of record.
    (C) System leakage tests: Third provision. The use of the 
provisions for an alternative BWR pressure test at reduced pressure to 
satisfy IWA-4540 requirements as described in IWA-5213(b)(2), IWB-
5210(c) and IWB-5221(d) of Section XI, 2017 Edition may be used subject 
to the following conditions:
    (1) The use of nuclear heat to conduct the BWR Class 1 system 
leakage test is prohibited (i.e., the reactor must be in a non-critical 
state), except during refueling outages in which the ASME Section XI 
Category B-P pressure test has already been performed, or at the end of 
mid-cycle maintenance outages fourteen (14) days or less in duration.
    (2) In lieu of the test condition holding time of IWA-5213(b)(2), 
after pressurization to test conditions, and before the visual 
examinations commence, the holding time shall be 1 hour for non-
insulated components.
* * * * *
    (xxi) * * *
    (B) Table IWB-2500-1 examination. Use of the provisions of IWB-
2500(f) and (g) and Table IWB-2500-1 Notes 6 and 7 of the 2017 Edition 
of ASME Section XI for examination of Examination Category B-D Item 
Numbers B3.90 and B3.100 shall be subject to the following conditions:
    (1) A plant-specific evaluation demonstrating the criteria of IWB-
2500(f) are met must be maintained in accordance with IWA-1400(l).
    (2) The use of the provisions of IWB-2500(f) and Table IWB-2500-1 
Note 6 for examination of Examination Category B-D Item Numbers B3.90 
is prohibited for plants with renewed licenses in accordance with 10 
CFR part 54.
    (3) The provisions of IWB-2500(g) and Table IWB-2500-1 Notes 6 and 
7 for examination of Examination Category B-D Item Numbers B3.90 and 
B3.100 shall not be used to eliminate the preservice or inservice 
volumetric examination of plants with a Combined Operating License 
pursuant to 10 CFR part 52, or a plant that receives its operating 
license after October 22, 2015.
* * * * *
    (xxv) Section XI condition: Mitigation of defects by modification. 
Use of the provisions of IWA-4340 shall be subject to the following 
conditions:
    (A) Mitigation of defects by modification: First provision. The use 
of the provisions for mitigation of defects by modification in IWA-4340 
of Section XI 2001 Edition through the 2010 Addenda, is prohibited.
    (B) Mitigation of defects by modification: Second provision. The 
provisions for mitigation of defects by modification in IWA-4340 of 
Section XI 2011 Edition through the 2017 Edition may be used subject to 
the following conditions:
    (1) The use of the provisions in IWA 4340 to mitigate crack-like 
defects or those associated with flow accelerated corrosion are 
prohibited.
    (2) The design of a modification that mitigates a defect shall 
incorporate a loss of material rate either 2 times the actual measured 
corrosion rate in that pipe location (established based on wall 
thickness measurements conducted at least twice in two prior 
consecutive or nonconsecutive refueling outage cycles in the 10 year 
period prior to installation of the modification), or 4 times the 
estimated maximum corrosion rate for the piping system.
    (3) The licensee shall perform a wall thickness examination in the 
vicinity of the modification and relevant pipe base metal. Except as 
provided in paragraphs (b)(2)(xxv)(B)(3)(i) and (ii), the examination 
must be performed during each refueling outage cycle to detect 
propagation of the defect into the material credited for structural 
integrity of the item unless the examinations in the two refueling 
outage cycles subsequent to the installation of the modification are 
capable of validating the projected flaw growth. Where the projected 
flaw growth has been validated, the modification must be examined at 
half its expected life or once per interval, whichever is smaller.
    (i) For buried pipe locations where the loss of material has 
occurred due to internal corrosion, the refueling outage interval wall 
thickness examinations may be conducted at a different location in the 
same system as long as: Wall thickness measurements were conducted at 
the different location at the same time as installation of the 
modification; the flow rate is the same or higher at the different 
location; the piping configuration is the same (e.g., straight run of 
pipe, elbow, tee), and if pitting occurred at the modification

[[Page 26579]]

location, but not the different location, wall loss values must be 
multiplied by four. Where wall loss values are greater than that 
assumed during the design of the modification, the structural integrity 
of the modification shall be reanalyzed. Additionally, if the extent of 
degradation is different (i.e., through wall, percent wall loss plus or 
minus 25 percent) or the corrosion mechanism (e.g., general, pitting) 
is not the same at the different location as at the modification 
location, the modification must be examined at half its expected life 
or 10 years, whichever is smaller.
    (ii) For buried pipe locations where loss of material has occurred 
due to external corrosion, the modification must be examined at half 
its expected life or 10 years, whichever is smaller.
    (xxvi) Section XI condition: Pressure testing Class 1, 2, and 3 
mechanical joints. When using the 2001 Edition through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(ii) 
of this section, licensees shall pressure test in accordance with IWA-
5211(a) mechanical joints in Class 1, 2, and 3 piping and components 
greater than NPS-1 which are disassembled and reassembled during the 
performance of a Section XI repair/replacement activity requiring 
documentation on a Form NIS-2. The system pressure test and NDE 
examiners shall meet the requirements of the licensee's/applicant's 
current ISI code of record.
* * * * *
    (xxxii) Section XI condition: Summary report submittal. When using 
ASME BPV Code, Section XI, 2010 Edition through the latest edition and 
addenda incorporated by reference in paragraph (a)(1)(ii) of this 
section, Summary Reports and Owner's Activity Reports described in IWA-
6230 must be submitted to the NRC. Preservice inspection reports for 
examinations prior to commercial service shall be submitted prior to 
the date of placement of the unit into commercial service. For 
preservice and inservice examinations performed following placement of 
the unit into commercial service, reports shall be submitted within 90 
calendar days of the completion of each refueling outage.
* * * * *
    (xxxiv) Section XI condition: Nonmandatory Appendix U. When using 
Nonmandatory Appendix U of the ASME BPV Code, Section XI, 2013 Edition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section, the following conditions apply:
* * * * *
    (xxxv) Section XI condition: Use of RTT0 in the 
KIa and KIc equations.
    (A) When using the 2013 Edition of the ASME BPV Code, Section XI, 
Appendix A, paragraph A-4200, if T0 is available, then 
RTT0 may be used in place of RTNDT for 
applications using the KIc equation and the associated 
KIc curve, but not for applications using the KIa 
equation and the associated KIa curve.
    (B) When using the 2015 Edition of the ASME BPV Code, Section XI, 
Appendix A, paragraph A-4200 subparagraph (c) RTKIa shall be 
defined as RTKIa = T0 + 90.267 exp(-
0.003406T0) for U.S. Customary Units.
* * * * *
    (xxxviii) Section XI condition: ASME Code Section XI Appendix III 
Supplement 2. Licensees applying the provisions of ASME Code Section XI 
Appendix III Supplement 2, ``Welds in Cast Austenitic Materials,'' are 
subject to the following conditions:
    (A) ASME Code Section XI Appendix III Supplement 2: First 
provision. In lieu of Paragraph (c)(1)(-c)(-2), licensees shall use a 
search unit with a center frequency of 500 kHz with a tolerance of +/- 
20 percent.
    (B) ASME Code Section XI Appendix III Supplement 2: Second 
provision. In lieu of Paragraph (c)(1)(-d), the search unit shall 
produce angles including, but not limited to, 30 to 55 degrees with a 
maximum increment of 5 degrees.
    (xxxix) Section XI condition: Defect Removal. The use of the 
provisions for removal of defects by welding or brazing in IWA-
4421(c)(1) and IWA-4421(c)(2) of Section XI, 2017 Edition may be used 
subject to the following conditions:
    (A) Defect removal requirements: First provision. The provisions of 
subparagraph IWA 4421(c)(1) shall not be used to contain or isolate a 
defective area without removal of the defect.
    (B) Defect removal requirements: Second provision. The provisions 
of subparagraph IWA-4421(c)(2) shall not be used for crack-like 
defects.
    (xl) Section XI condition: Prohibitions on use of IWB-3510.4(b). 
The use of ASME BPV Code, Section XI, 2017 Edition, Subparagraphs IWB-
3510.4(b)(4) and IWB-3510.4(b)(5) is prohibited.
    (xli) Section XI condition: Preservice Volumetric and Surface 
Examinations Acceptance. The use of the provisions for accepting flaws 
by analytical evaluation during preservice inspection in IWB-3112(a)(3) 
and IWC-3112(a)(3) of Section XI, 2013 Edition through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(ii) 
of this section is prohibited.
    (xlii) Section XI condition: Steam Generator Nozzle-to-Component 
welds and Reactor Vessel Nozzle-to-Component welds. Licensees applying 
the provisions of Table IWB-2500-1, Examination Category B-F, Pressure 
Retaining Dissimilar Metal Welds in Vessel Nozzles, Item B5.11 (NPS 4 
or Larger Nozzle-to-Component Butt Welds) of the 2013 Edition through 
the latest edition and addenda incorporated by reference in paragraph 
(a)(1)(ii) of this section and Item B5.71 (NPS 4 or Larger Nozzle-to-
Component Butt Welds) of the 2011a Addenda through the latest edition 
and addenda incorporated by reference in paragraph (a)(1)(ii) of this 
section must also meet the following conditions:
    (A) Ultrasonic examination procedures, equipment, and personnel 
shall be qualified by performance demonstration in accordance with 
Mandatory Appendix VIII.
    (B) When applying the examination requirements of Figure IWB-2500-
8, the volumetric examination volume shall be extended to include 100 
percent of the weld volume, except as provided in paragraph 
(b)(2)(xlii)(B)(1) of this section:
    (1) If the examination volume that can be obtained by performance 
demonstration qualified procedures is less than 100 percent of the weld 
volume, the licensee may ultrasonically examine the qualified volume 
and perform a flaw evaluation of the largest hypothetical crack that 
could exist in the volume not qualified for ultrasonic examination, 
subject to prior NRC authorization in accordance with paragraph (z) of 
this section.
    (2) [Reserved]
    (3) * * * When implementing the ASME OM Code, conditions are 
applicable only as specified in the following paragraphs:
* * * * *
    (iv) OM condition: Check valves (Appendix II). Licensees applying 
Appendix II of the ASME OM Code, 2003 Addenda through the 2015 Edition, 
is acceptable for use with the following requirements. Trending and 
evaluation shall support the determination that the valve or group of 
valves is capable of performing its intended function(s) over the 
entire interval. At least one of the Appendix II condition monitoring 
activities for a valve group shall be performed on each valve of the 
group at approximate equal intervals not to exceed the maximum interval 
shown in the following table:
* * * * *
    (ix) OM condition: Subsection ISTF. Licensees applying Subsection 
ISTF,

[[Page 26580]]

2012 Edition or 2015 Edition, shall satisfy the requirements of 
Mandatory Appendix V, ``Pump Periodic Verification Test Program,'' of 
the ASME OM Code in that edition. Subsection ISTF, 2011 Addenda, is 
prohibited for use.
* * * * *
    (xi) OM condition: Valve Position Indication. When implementing 
paragraph ISTC-3700, ``Position Verification Testing,'' in the ASME OM 
Code, 2012 Edition through the latest edition and addenda of the ASME 
OM Code incorporated by reference in paragraph (a)(1)(iv) of this 
section, licensees shall verify that valve operation is accurately 
indicated by supplementing valve position indicating lights with other 
indications, such as flow meters or other suitable instrumentation to 
provide assurance of proper obturator position for valves with remote 
position indication within the scope of Subsection ISTC including its 
mandatory appendices and their verification methods and frequencies.
* * * * *
    (g) * * *
    (4) * * *
    (i) * * * Licensees using this option must also use the same 
edition and addenda of Appendix I, Subarticle I-3200, as Appendix VIII, 
including any applicable conditions listed in paragraph (b) of this 
section.
    (ii) * * * Licensees using this option must also use the same 
edition and addenda of Appendix I, Subarticle I-3200, as Appendix VIII, 
including any applicable conditions listed in paragraph (b) of this 
section.
* * * * *
    (6) * * *
    (ii) * * *
    (C) [Reserved]
    (D) Augmented ISI requirements: Reactor vessel head inspections--
(1) Implementation. Holders of operating licenses or combined licenses 
for pressurized-water reactors as of or after June 3, 2020 shall 
implement the requirements of ASME BPV Code Case N-729-6 instead of 
ASME BPV Code Case N-729-4, subject to the conditions specified in 
paragraphs (g)(6)(ii)(D)(2) through (8) of this section, by no later 
than one year after June 3, 2020. All previous NRC-approved 
alternatives from the requirements of paragraph (g)(6)(ii)(D) of this 
section remain valid.
    (2) Appendix I use. If Appendix I is used, Section I-3000 must be 
implemented to define an alternative examination area or volume.
* * * * *
    (4) Surface exam acceptance criteria. In addition to the 
requirements of paragraph 3132.1(b) of ASME BPV Code Case N-729-6, a 
component whose surface examination detects rounded indications greater 
than allowed in paragraph NB-5352 in size on the partial-penetration or 
associated fillet weld shall be classified as having an unacceptable 
indication and corrected in accordance with the provisions of paragraph 
3132.2 of ASME BPV Code Case N-729-6.
    (5) Peening. In lieu of inspection requirements of Table 1, Items 
B4.50 and B4.60, and all other requirements in ASME BPV Code Case N-
729-6 pertaining to peening, in order for a RPV upper head with nozzles 
and associated J-groove welds mitigated by peening to obtain 
examination relief from the requirements of Table 1 for unmitigated 
heads, peening must meet the performance criteria, qualification, and 
examination requirements stated in MRP-335, Revision 3-A, with the 
exception that a plant-specific alternative request is not required and 
NRC condition 5.4 of MRP-335, Revision 3-A does not apply.
    (6) Baseline Examinations. In lieu of the requirements for Note 
7(c) the baseline volumetric and surface examination for plants with a 
RPV Head with less than 8 EDY shall be performed by 2.25 reinspection 
years (RIY) after initial startup not to exceed 8 years.
    (7) Sister Plants. Note 10 of ASME BPV Code Case N-729-6 shall not 
be implemented without prior NRC approval.
    (8) Volumetric Leak Path. In lieu of paragraph 3200(b) requirement 
for a surface examination of the partial penetration weld, a volumetric 
leak path assessment of the nozzle may be performed in accordance with 
Note 6 of Table 1 of N-729-6.
* * * * *
    (F) Augmented ISI requirements: Examination requirements for Class 
1 piping and nozzle dissimilar-metal butt welds--(1) Implementation. 
Holders of operating licenses or combined licenses for pressurized-
water reactors as of or after June 3, 2020, shall implement the 
requirements of ASME BPV Code Case N-770-5 instead of ASME BPV Code 
Case N-770-2, subject to the conditions specified in paragraphs 
(g)(6)(ii)(F)(2) through (16) of this section, by no later than one 
year after June 3, 2020. All NRC authorized alternatives from previous 
versions of paragraph (g)(6)(ii)(F) of this section remain applicable.
    (2) Categorization. (i) Welds that have been mitigated by the 
Mechanical Stress Improvement Process (MSIP\TM\) may be categorized as 
Inspection Items D or E, as appropriate, provided the criteria in 
Appendix I of the code case have been met.
    (ii) In order to be categorized as peened welds, in lieu of 
inspection category L requirements and examinations, welds must meet 
the performance criteria, qualification and examination requirements as 
stated by MRP-335, Revision 3-A, with the exception that no plant-
specific alternative is required.
    (iii) Other mitigated welds shall be identified as the appropriate 
inspection item of the NRC authorized alternative or NRC-approved code 
case for the mitigation type in Regulatory Guide 1.147.
    (iv) All other butt welds that rely on Alloy 82/182 for structural 
integrity shall be categorized as Inspection Items A-1, A-2, B-1 or B-
2, as appropriate.
    (v) Paragraph -1100(e) of ASME BPV Code Case N-770-5 shall not be 
used to exempt welds that rely on Alloy 82/182 for structural integrity 
from any requirement of this section.
* * * * *
    (4) Examination coverage. When implementing Paragraph -2500(a) of 
ASME BPV Code Case N-770-5, essentially 100 percent of the required 
volumetric examination coverage shall be obtained, including greater 
than 90 percent of the volumetric examination coverage for 
circumferential flaws. Licensees are prohibited from using Paragraphs -
2500(c) and -2500(d) of ASME BPV Code Case N-770-5 to meet examination 
requirements.
* * * * *
    (6) Reporting requirements. The licensee will promptly notify the 
NRC regarding any volumetric examination of a mitigated weld that 
detects growth of existing flaws in the required examination volume 
that exceed the previous IWB-3600 flaw evaluations, new flaws, or any 
indication in the weld overlay or excavate and weld repair material 
characterized as stress corrosion cracking. Additionally, the licensee 
will submit to the NRC a report summarizing the evaluation, along with 
inputs, methodologies, assumptions, and causes of the new flaw or flaw 
growth within 30 days following plant startup.
* * * * *
    (9) Deferrals. (i) The initial inservice volumetric examination of 
optimized weld overlays, Inspection Item C-2, shall not be deferred.
    (ii) Volumetric inspection of peened dissimilar metal butt welds 
shall not be deferred.
    (iii) For Inspection Item M-2, N-1 and N-2 welds, the second 
required

[[Page 26581]]

inservice volumetric examination shall not be deferred.
    (10) Examination technique. Note 14(b) of Table 1 and Note (b) of 
Figure 5(a) of ASME BPV Code Case N-770-5 may only be implemented if 
the requirements of Note 14(a) of Table 1 of ASME BPV Code Case N-770-5 
cannot be met.
* * * * *
    (13) Encoded ultrasonic examination. Ultrasonic examinations of 
non-mitigated or cracked mitigated dissimilar metal butt welds in the 
reactor coolant pressure boundary must be performed in accordance with 
the requirements of Table 1 for Inspection Item A-1, A-2, B-1, B-2, E, 
F-2, J, K, N-1, N-2 and O. Essentially 100 percent of the required 
inspection volume shall be examined using an encoded method.
    (14) Excavate and weld repair cold leg. For cold leg temperature M-
2, N-1 and N-2 welds, initial volumetric inspection after application 
of an excavate and weld repair (EWR) shall be performed during the 
second refueling outage.
    (15) Cracked excavate and weld repair. In lieu of the examination 
requirements for cracked welds with 360 excavate and weld repairs, 
Inspection Item N-1 of Table 1, welds shall be examined during the 
first or second refueling outage following EWR. Examination volumes 
that show no indication of crack growth or new cracking shall be 
examined once each inspection interval thereafter.
    (16) Partial arc excavate and weld repair. Inspection Item O cannot 
be used without NRC review and approval.
* * * * *

    Dated this 15th day of April, 2020.

    For the Nuclear Regulatory Commission.
Ho K. Nieh,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2020-08855 Filed 5-1-20; 8:45 am]
BILLING CODE 7590-01-P