American Society of Mechanical Engineers 2021-2022 Code Editions, 53384-53402 [2023-16686]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 88, Number 151 (Tuesday, August 8, 2023)]
[Proposed Rules]
[Pages 53384-53402]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-16686]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 88 , No. 151 / Tuesday, August 8, 2023 / 
Proposed Rules

[[Page 53384]]



NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2018-0289]
RIN 3150-AK21


American Society of Mechanical Engineers 2021-2022 Code Editions

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to 
amend its regulations to incorporate by reference the 2021 Edition of 
the American Society of Mechanical Engineers Boiler and Pressure Vessel 
Code and the 2022 Edition of the American Society of Mechanical 
Engineers Operation and Maintenance of Nuclear Power Plants, Division 
1: OM Code: Section IST, for nuclear power plants. 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. This amendment also incorporates editorial changes that do 
not change the technical information.

DATES: Submit comments by October 23, 2023. Comments received after 
this date will be considered if it is practical to do so, but the NRC 
is able to ensure consideration only for comments received on or before 
this date.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specific subject); however, the NRC encourages electronic 
comment submission through the Federal rulemaking website:
     Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0289. Address 
questions about NRC dockets to Dawn Forder; telephone: 301-415-3407; 
email: [email protected]. For technical questions contact the 
individuals listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     Email comments to: [email protected]. If you do 
not receive an automatic email reply confirming receipt, then contact 
us at 301-415-1677.
     Fax comments to: Secretary, U.S. Nuclear Regulatory 
Commission at 301-415-1101.
     Mail comments to: Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and 
Adjudications Staff.
     Hand deliver comments to: 11555 Rockville Pike, Rockville, 
Maryland 20852, between 7:30 a.m. and 4:15 p.m. (eastern time) Federal 
workdays; telephone: 301-415-1677.
    For additional direction on obtaining information and submitting 
comments, see ``Obtaining Information and Submitting Comments'' in the 
SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Tyler Hammock, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1381, email: 
[email protected] and Michael Benson, Office of Nuclear Reactor 
Regulation, telephone: 301-415-2425, 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 proposing to amend its regulations to incorporate by 
reference the 2021 Edition of the American Society of Mechanical 
Engineers (ASME) Boiler and Pressure Vessel Code (BPV Code) and the 
2022 Edition of the ASME Operation and Maintenance of Nuclear Power 
Plants, Division 1: OM Code: Section IST (OM Code), for nuclear power 
plants.
    The ASME periodically revises and updates its Codes for nuclear 
power plants by issuing new editions; this proposed rule is in 
accordance with the NRC's practice to incorporate those new editions 
into the NRC's regulations. This proposed 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 BPV and OM Codes (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 XIII 
of this document, ``Voluntary Consensus Standards.''

B. Major Provisions

    Major provisions of this proposed rule include the incorporation by 
reference with conditions of the following ASME Codes into NRC 
regulations and delineation of NRC requirements for the use of these 
Codes:

 The 2021 Edition of the BPV Code
 The 2022 Edition of the OM Code

C. Costs and Benefits

    The NRC prepared a draft regulatory analysis to determine the 
expected costs and benefits of this proposed rule. The regulatory 
analysis identifies costs and benefits in both a quantitative fashion 
as well as in a qualitative fashion.
    The analysis concludes that this proposed rule would result in a 
net quantitative averted cost to the industry and a net cost to the 
NRC. This proposed rule, relative to the regulatory baseline, would 
result in a net averted cost for industry of $0.65 million based on a 
7-percent net present value (NPV) and $0.72 million based on a 3-
percent NPV. This proposed rule, relative to the regulatory baseline, 
would result in a net cost to the NRC of $44 thousand based on a 7-
percent NPV to $10 thousand based on a 3-percent NPV. Qualitative 
factors that were considered include regulatory stability and 
predictability, regulatory efficiency, and consistency with the NTTAA. 
The regulatory analysis shows that the rulemaking is justified because 
the total quantified benefits of the proposed regulatory action exceed 
the costs of the proposed action. When the qualitative benefits 
(including the safety benefit and improvement in knowledge) are 
considered together with the quantified benefits, the benefits outweigh 
the identified quantitative and qualitative costs.

[[Page 53385]]

    The NRC has had a decades-long practice of approving and/or 
mandating the use of certain parts of editions and addenda of these 
ASME Codes in Sec.  50.55a. Continuing this practice in this proposed 
rule ensures regulatory stability and predictability. This practice 
also provides consistency across the industry and provides assurance to 
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 undergo extensive external 
review before the NRC considers whether to incorporate them by 
reference. 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 draft regulatory analysis 
(Accession No. ML23032A316 in the NRC's Agencywide Documents Access and 
Management System (ADAMS)).

Table of Contents

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

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2018-0289 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-2018-0289.
     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 ``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, at 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.
     NRC's PDR: You may examine and purchase copies of public 
documents, by appointment, at the NRC's PDR, Room P1 B35, One White 
Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make 
an appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time, Monday through Friday, except Federal 
holidays.

B. Submitting Comments

    The NRC encourages electronic comment submission through the 
Federal rulemaking website (https://www.regulations.gov). Please 
include Docket ID NRC-2018-0289 in your comment submission.
    The NRC cautions you not to include identifying or contact 
information that you do not want to be publicly disclosed in your 
comment submission. The NRC will post all comment submissions at 
https://www.regulations.gov as well as enter the comment submissions 
into ADAMS. The NRC does not routinely edit comment submissions to 
remove identifying or contact information.
    If you are requesting or aggregating comments from other persons 
for submission to the NRC, then you should inform those persons not to 
include identifying or contact information that they do not want to be 
publicly disclosed in their comment submission. Your request should 
state that the NRC does not routinely edit comment submissions to 
remove such information before making the comment submissions available 
to the public or entering the comment into ADAMS.

II. Background

    The American Society of Mechanical Engineers develops and publishes 
the ASME BPV Code, which contains requirements for the design, 
construction, and inservice inspection (ISI) of nuclear power plant 
components, and the ASME 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 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 of 
the ASME Codes do not significantly change code philosophy or approach.
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    \1\ The editions and addenda of the ASME Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
2005 to 2019 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 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 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 of the ASME BPV and OM

[[Page 53386]]

Codes were last incorporated by reference into the NRC's regulations in 
a final rule dated October 27, 2022 (87 FR 65128).
    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 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. If 
the NRC believes that there is a significant technical or regulatory 
concern with a provision in an ASME-approved Code edition being 
considered for incorporation by reference, then the NRC conditions the 
use of that provision when it incorporates by reference that ASME Code 
edition 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 (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 proposed rule, the provisions of 
the 2021 Edition of Section III, Division 1; the 2021 Edition of 
Section XI, Division 1, of the ASME BPV Code; and the 2022 Edition of 
the ASME OM Code that the NRC are not adopting, or are 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 proposed rule that the NRC finds to be 
conditionally acceptable, together with the applicable 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 XIII of this 
document, ``Voluntary Consensus Standards.''

III. Discussion

    The NRC regulations incorporate by reference ASME Codes for nuclear 
power plants. This proposed 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 proposed 
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 of 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 proposed rule. First, the NRC 
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 
staff to ensure an adequate technical review. Third, the NRC position 
on each Code is reviewed and approved by NRC management as part of this 
proposed 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, assures that the NRC approves 
for use only those new and revised code editions, 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 reviewed changes to the Codes in the editions identified in 
this proposed rule. The NRC concluded, in accordance with the process 
for review of changes to the Codes, that these editions of the Codes 
are technically adequate, consistent with current NRC regulations, and 
approved for use with the specified conditions upon the conclusion of 
the rulemaking process.
    The NRC is proposing to amend its regulations to incorporate by 
reference:
     The 2021 Editions of the ASME BPV Code, Section III, 
Division 1 and Section XI, Division 1, with conditions on their use.
     The 2022 Edition of Division 1 of the ASME OM Code, 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 2019 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(1)(i) through (xiii). This proposed rule would revise 
Sec.  50.55a(a)(1)(i) to incorporate by reference the 2021 Edition 
(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, 1974 Edition through the 1975 
Summer Addenda, the 1995 Edition (Division 1) through the 1997 Addenda 
(Division 1), and the 2001 Edition (Division 1) through the 2019 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(2)(i) through (xliii). This proposed rule would revise 
Sec.  50.55a(a)(1)(ii) to incorporate by reference the 2021 Edition 
(Division 1) of the ASME BPV Code, Section XI. It would also clarify 
the wording and add, remove, or revise some of the conditions as 
explained in this proposed rule.
    The current regulations in Sec.  50.55a(a)(1)(iv) incorporate by 
reference ASME OM Code, 1995 Edition through the 2020 Edition (with 
some omissions of specific editions and addenda), subject to the 
conditions currently identified in Sec.  50.55a(b)(3)(i) through (xi). 
This proposed rule would revise Sec.  50.55a(a)(1)(iv) to incorporate 
by reference the 2022 Edition of Division 1 of the ASME OM Code.
    In the introductory discussion of its Codes, ASME specifies that 
errata to those Codes may be posted on the ASME website under the 
Committee Pages to provide corrections to incorrectly published items, 
or to correct typographical or grammatical errors in those Codes. Users 
of the ASME BPV Code and ASME OM Code should be aware of errata when 
implementing the specific provisions of those Codes. Applicants and 
licensees should monitor errata to determine when they might need to 
submit a request for an alternative under Sec.  50.55a(z) to implement 
provisions specified in an errata to their ASME Code of record. Each of 
the proposed NRC conditions and the reasons for each are discussed in 
the following sections

[[Page 53387]]

of this document. The discussions are organized under the applicable 
ASME Code and Section.
    The NRC prepared an unofficial redline strikeout version of the 
proposed changes to regulatory text that is intended to help the reader 
identify the proposed changes. The unofficial redline strikeout version 
of the proposed rule is publicly available and is listed in the 
``Availability of Documents'' section.

A. ASME BPV Code, Section III

Section 50.55a(a)(1)(i)(E) Rules for Construction of Nuclear Facility 
Components--Division 1
    The NRC proposes to revise Sec.  50.55a(a)(1)(i)(E) to incorporate 
by reference the 2021 Edition of the ASME BPV Code, Section III, 
including Subsection NCA and Division 1 Subsections NB through NG 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. 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 they required by NRC regulations and, 
therefore, such information is not relevant to NRC applicants and 
licensees. 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. Therefore, this proposed rule would 
revise the introductory text to Sec.  50.55a(a)(1)(i)(E) to reference 
the 2021 Edition of the ASME BPV Code, Section III, including 
Subsection NCA and Division 1 Subsections NB through NG and Appendices.
Section 50.55a(b)(1)(iv) Section III Condition: Quality Assurance
    The NRC proposes to incorporate by reference Subsection NCA of 2021 
Edition BPV Code, ASME Section III with the exception that Subpart 2.19 
in NQA-1-2017, NQA-1-2019 and NQA-1-2022 is not approved for use.
    With regards to the implementation of NCA-3126, NCA-3127, NCA-
4255.3, and NCA-4254.3 for the procurement of calibration and testing 
services, the NRC reminds the users of the ASME Code that the 
procurement of commercial grade calibration and testing services 
remains subject to NRC requirements in 10 CFR part 21 and in appendix B 
to 10 CFR part 50.
    For implementation of procurement of calibration and testing 
services, the NRC recently proposed a draft regulatory guide (DG), DG-
1403, ``Quality Assurance Program Criteria (Design and Construction)'' 
(ML22304A054) that would, among other things, endorse Nuclear Energy 
Institute (NEI) 14-05A, ``Guidelines for the Use of Accreditation in 
Lieu of Commercial Grade Surveys for Procurement of Laboratory 
Calibration and Test Services,'' Revision 1, issued November 2020 (88 
FR 27713). As described in the DG licensees and suppliers of basic 
components can take credit for the ILAC accreditation process as 
described in NEI 14-05A Revision 1 in lieu of performing on-site 
commercial-grade surveys as part of the commercial-grade dedication of 
calibration and testing services. The NRC's proposed endorsement would 
be for use of NEI 14-05A Revision 1 in lieu of Subpart 2.19 in NQA-1-
2017, NQA-1-2019 and NQA-1-2022, which DG-1403 found to not incorporate 
the controls and conditions necessary for use. Specifically, Subpart 
2.19 allows the laboratory accreditation to be performed remotely, 
which the NRC has determined is not adequate to meet the requirements 
of appendix B to 10 CFR part 50. Therefore, the NRC is proposing a 
condition to prohibit the use of Subpart 2.19 in NQA-1-2017.
Section 50.55a(b)(1)(vi) Section III Condition: Subsection NH
    The NRC proposes to revise this condition to change the word 
``sleeves'' to ``sheaths'' and to note that this condition is not 
applicable to the 2015 Edition and later editions as Subsection NH has 
been deleted from Section III Division 1.
Section 50.55a(b)(1)(xi) Section III Condition: Mandatory Appendix XXVI
    The NRC proposes to revise this condition. 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 first provision, as noted in 
50.55a(b)(1)(xi)(A). When applying the 2015 through 2021 Editions of 
Section III, Mandatory Appendix XXVI, ``Rules for Construction of Class 
3 Buried Polyethylene Pressure Piping,'' applicants or licensees must 
meet the second provision, as noted in 50.55a(b)(1)(xi)(B). When 
applying the 2017 Edition of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the third provision, as 
noted in 50.55a(b)(1)(xi)(C).
Section 50.55a(b)(1)(xiii) Section III Condition: Preservice Inspection 
of Steam Generator Tubes
    The NRC proposes to revise Sec.  50.55a(b)(1)(xiii) including the 
first provision, Sec.  50.55a(b)(1)(xiii)(A), and second provision, 
Sec.  50.55a(b)(1)(xiii)(B), to extend the applicability of the 
conditions through the latest edition of the ASME BPV Code, Section III 
incorporated by reference in paragraph (a)(1)(i). The 2021 Edition of 
Section III was not updated to include the provisions of this 
condition. Therefore, the NRC is proposing to revise this condition to 
apply to the latest edition incorporated by reference.
Section 50.55a(b)(1)(xiv) Section III Condition: Repairs to Stamped 
Components
    The NRC is proposing to add a condition that if Nonmandatory 
Appendix NN is used for the elimination of surface defects and repairs 
of stamped components prior to the completion of Form N-3 Data Report, 
all applicable requirements of Nonmandatory Appendix NN shall be met. 
The 2021 Edition included Nonmandatory Appendix NN and stated in the 
provisions of NCA-8151 and NCA-8500 in the 2021 Edition of Section III 
that guidance for the elimination of surface defects and repairs of 
stamped components prior to the completion of Form N-3 Data Report is 
contained within Nonmandatory Appendix NN.
    The section titled ``Organization of Section III'' within Section 
III and the ``Introduction'' to Section III Appendices state that 
``Mandatory Appendices are referred to in the Section III rules and 
contain requirements that must be followed in construction. 
Nonmandatory Appendices provide additional information or guidance when 
using Section III.'' In addition, Nonmandatory Appendix NN states, 
``This Appendix provides guidance for the removal of external surface 
defects from piping, pumps, and valves and performing repairs to 
stamped components after certification and prior to completion of the 
N-3 Data Report.'' It should also be noted that the NRC only endorses 
Mandatory Appendices of Section III to the ASME Code in the regulations 
(Sec.  50.55a).

[[Page 53388]]

    Since this Nonmandatory Appendix is not required to be followed by 
the ASME Code, all or none of the requirements proposed in the appendix 
may be performed and the certificate holder or owner potentially could 
make repairs that do not meet the code requirements, introduce flaws or 
retain defects, or not disposition defects that can compromise the 
structural integrity of the component and not properly document the 
repair. It should be noted that Nonmandatory Appendix NN was developed 
by combining Code Cases N-801-3 and N-870-1 into the Nonmandatory 
Appendix NN. NRC approved Code Cases N-801-3 and N-870-1 in RG 1.84, 
Revision 39. Licensees that used Code Cases N-801-3 and N-870-1 were 
required to meet all the requirements in the applicable Code Cases. The 
NRC considers the information in Nonmandatory Appendix NN as 
requirements, consistent with the Code Cases, that are necessary to 
ensure certificate holders make satisfactory repairs to stamped ASME 
Code, Section III components. Therefore, the NRC is adding Sec.  
50.55a(b)(1)(xiv) to condition the provision of NCA-8151, NCA-8500, and 
Nonmandatory Appendix NN to require that all the requirements in 
Nonmandatory Appendix NN shall be met when used.

B. ASME BPV Code, Section XI

Section 50.55a(a)(1)(ii) ASME Boiler and Pressure Vessel Code, Section 
XI
    The NRC proposes to amend the regulations in Sec.  
50.55a(a)(1)(ii)(C) to incorporate by reference the 2021 Edition 
(Division 1) of the ASME BPV Code, Section XI. The current regulations 
in Sec.  50.55a(a)(1)(ii)(C) incorporate by reference ASME BPV Code, 
Section XI, the 1974 Edition through the 1975 Summer Addenda, the 1995 
Edition (Division 1) through the 1997 Edition (Division 1), and the 
2001 Edition (Division 1) through the 2019 Edition (Division 1), 
subject to the conditions identified in current Sec.  50.55a(b)(2)(i) 
through (xliii).
Section 50.55a(b)(2) Conditions on ASME BPV Code Section XI
    The NRC proposes to revise the definition of Section XI in Sec.  
50.55a(b)(2) to refer to the editions of the ASME BPV Code, Section XI 
incorporated by reference in paragraph (a)(1)(ii).
Section 50.55a(b)(2)(viii) Section XI Condition: Concrete Containment 
Examinations
    The NRC proposes not to apply the existing conditions in Sec.  
50.55a(b)(2)(viii)(H) and Sec.  50.55a(b)(2)(viii)(I), the eighth and 
ninth provisions for concrete containment examinations, to the 2021 
Edition of the ASME Code. Revisions to IWA-6230 require the information 
described in the existing Sec.  50.55a(b)(2)(viii)(H) condition be 
included in the required Owner's Activity Report (OAR). These new 
Section XI provisions address the requirement in the existing NRC 
condition. Revisions to IWL-2512 require the technical evaluation 
discussed in IWL-2512(b) be completed every five years. This new 
Section XI provision addresses the requirement in existing NRC 
condition Sec.  50.55a(b)(2)(viii)(I).
Section 50.55a(b)(2)(ix) Section XI Condition: Metal Containment 
Examinations
    The NRC proposes not to apply the existing condition in Sec.  
50.55a(b)(2)(ix)(A)(2), the first provision for metal containment 
examinations, to the 2021 Edition of the ASME Code. Revisions to 
IWA6230 require the information described in the existing Sec.  
50.55a(b)(2)(ix) condition be included in the required OAR. This new 
Section XI provision addresses the requirement in the existing NRC 
condition.
Section 50.55a(b)(2)(xv) Section XI Condition: Appendix VIII Specimen 
Set and Qualification Requirements
    The NRC proposes to eliminate this condition as it is no longer 
applicable to any licensee. This condition only applies to the use of 
the 1995 through the 2001 Editions of ASME Code Section XI, Appendix 
VIII. Additionally, Sec.  50.55a(b)(2)(xv) requires licensees using 
ASME Code Section XI Editions later than the 2001 Edition through the 
2006 Addenda to use the 2001 Edition of Appendix VIII. This condition 
therefore only applies to licensees using the 1995 to the 2006 Addenda 
of ASME Code Section XI.
    The 2007 edition of ASME Code Section XI was incorporated by 
reference in Sec.  50.55a in the rulemaking dated June 21, 2011 (76 FR 
36231). Given the requirement to update ISI programs every 120 Months, 
no licensee is still using the 2001 Edition of Appendix VIII. This 
condition is therefore unnecessary.
Section 50.55a(b)(2)(xxxiv) Section XI Condition: Nonmandatory Appendix 
U
    The NRC proposes to amend Sec.  50.55a(b)(2)(xxxiv) to prohibit the 
use of Nonmandatory Appendix U, Supplement U-S1 in the 2021 Edition of 
Section XI. Nonmandatory Appendix U, Supplement U-S1 provides licensees 
with a methodology for temporary acceptance of flaws in moderate energy 
Class 2 and 3 piping. However, Code Case N-513 provides the same rules. 
The NRC position is that licensees use the more frequently updated Code 
Case N-513 when seeking to temporarily accept flaws in moderate energy 
Class 2 and 3 piping. As the ASME continues to update Code Case N-513, 
there can be different requirements between the version allowed by 
Nonmandatory Appendix U and the NRC approved version of the Code Case. 
Furthermore, duplicative rules may create regulatory confusion both for 
licensees and NRC inspection staff, as well as pose a burden on the NRC 
to review and compare the two documents to ensure reasonable assurance 
of safety under all potential combinations of alternatives. Therefore, 
this proposed condition clarifies that the appropriate reference for 
temporary acceptance of flaws in moderate energy Class 2 and 3 piping 
is Code Case N-513, as dispositioned in the latest version of 
Regulatory Guide (RG) 1.147 incorporated by reference in Sec.  
50.55a(a)(3)(ii).
    The NRC proposes to modify the existing condition in Sec.  
50.55a(b)(2)(xxxiv) to update the version of ASME BPV Code Case N-513 
to the latest version currently approved in RG 1.147. The NRC proposes 
to renumber this existing condition to Sec.  50.55a(b)(2)(xxxiv)(A)(2) 
and revise Sec.  50.55a(b)(2)(xxxiv)(B) to reflect the added condition 
on Nonmandatory Appendix U, Supplement U-S1. The purpose of this change 
is for regulatory efficiency to minimize changes to this condition in 
future rulemakings and maintain the requirement consistent with the 
latest NRC approved version of Code Case N-513.
Section 50.55a(b)(2)(xliv) Section XI Condition: Nonmandatory Appendix 
Y
    The NRC proposes to add Sec.  50.55a(b)(2)(xliv) to prohibit the 
use of Y-2200, Y-2420, and Y-3200 in the 2021 Edition of Section XI. 
These articles provide three crack growth laws for use in Section XI 
flaw evaluations. However, Code Cases N-809, N-889, and N-643 
respectively provide the same crack growth laws. The NRC position is 
that licensees use the more frequently updated Code Cases when seeking 
to use these crack growth laws in Section XI flaw evaluations. 
Furthermore, duplicative rules may create regulatory confusion for 
licensees and additional burden on the NRC to review and compare the 
two documents to provide reasonable assurance of

[[Page 53389]]

safety when using the curves and defined variables. Therefore, this 
proposed condition clarifies that the appropriate references for crack 
growth laws are the respective Code Cases, as dispositioned in the 
latest edition of RG 1.147 incorporated by reference in Sec.  
50.55a(a)(3)(ii).
Section 50.55a(b)(2)(xlv) Section XI Condition: Pressure Testing of 
Containment Penetration Piping After Repair/Replacement Activities
    The NRC proposes to add Sec.  50.55a(b)(2)(xlv) to require that 
when applying the provisions of IWA-4540(a) and (e) of the 2021 Edition 
of the ASME Code, Section XI, a VT-2 examination of the area affected 
by the repair/replacement activity shall be conducted during the Type C 
test in appendix J to 10 CFR part 50. The 2021 Edition of the ASME 
Code, Section XI, revised IWA-4540(a) and (e) by incorporating the 
requirements of Code Case N-751. The NRC conditioned Code Case N-751 in 
RG 1.147, Revision 19, to require that nondestructive examination must 
be performed in accordance with IWA-4540(a)(2) of the 2002 Addenda of 
Section XI. This includes a VT-2 (visual examination during system 
walkdown) in accordance with IWA-5211.
    Upon incorporating Code Case N-751 and the NRC condition in RG 
1.147, the revised IWA-4540(a) and (e) did not fully address the NRC 
condition in RG 1.147 concerning performing the VT-2 (visual 
examination). The revised IWA-4540(a) moved the pressure testing 
requirements for ``[R]epair/replacement activities performed by welding 
or brazing on piping, including isolation valves, designated Class 2, 
that penetrates a containment vessel and where the balance of the 
piping system inside and outside the containment is not within the 
scope of Section XI'' to IWA-4540(e). Therefore, the specific 
requirement in IWA-4540(a) to require a VT-2 visual examination during 
pressure testing is not required. In addition, IWA-4540(e) in the 2021 
Edition of ASME Code, Section XI states that for pressure testing of 
these locations, a Type C test in appendix J to 10 CFR part 50, system 
leakage test in accordance with IWA-5211(a), or pneumatic test in 
accordance with IWA-5211(c), shall be performed. The NRC notes that 
IWA-5211 requires the VT-2, while neither IWA-5211(a) or (c) require a 
VT-2 (visual examination during walkdown). IWA-4540(e) also states that 
if ``there is detectable leakage during the Type C test in appendix J 
to 10 CFR part 50, the brazed joints or welds shall be tested to 
confirm there is no leakage through the brazed joints or welds.'' The 
NRC notes that the Type C test in appendix J to 10 CFR part 50 does not 
require a VT-2 (visual system walkdown) of the piping to verify the 
leakage or absence thereof, but only a decrease in pressure.
    Therefore, the NRC is adding Sec.  50.55a(b)(2)(xlv) to condition 
provisions IWA-4540(a) and (e) of the 2021 Edition of the ASME Code, 
Section XI, to require that a VT-2 examination of the area affected by 
the repair/replacement activity be conducted during the Type C test in 
appendix J to 10 CFR part 50 to be consistent with the previous NRC 
condition for Code Case N-751.
Section 50.55a(b)(2)(xlvi) Section XI Condition: Contracted Repair/
Replacement Organization Fabricating Items Offsite of the Owner's 
Facilities
    The NRC proposes to add Sec.  50.55a(b)(2)(xlvi) to prohibit a 
contracted Repair/Replacement Organization, when applying the 
provisions of IWA-4143 in the 2021 Edition of the ASME Code, Section 
XI, from fabricating an item off-site of the Owner's facility (e.g., 
vendor facility) without an ASME Certificate of Authorization and 
without applying an ASME Stamp/Certification Mark.
    IWA-4143 in the 2021 Edition of the ASME Code, Section XI, allows 
an owner to procure ASME Code, Section III parts, appurtenances, piping 
subassemblies, and supports (hereinafter referred to as items) with no 
ASME Stamp/Certification Mark from a Repair/Replacement Organization 
that does not have an ASME Certificate of Authorization and conducts 
fabrication activities off-site of the Owner's facility. Therefore, a 
contracted Repair/Replacement Organization would be able to fabricate 
an item off-site (at a vendor facility) without an ASME Certificate of 
Authorization and not apply a Stamp/Certification Mark on the item. 
This contradicts NCA-8330 in ASME Code, Section III, which only allows 
an item with no ASME Stamp/Certification Mark applied to the item for 
an organization with an ASME Certificate of Authorization, since the 
organization with an ASME Certificate of Authorization is required to 
follow additional controls of the part in NCA-8330(a)(1) through (3). 
IWA-4131 in the 2021 Edition of the ASME Code, Section XI, does not 
provide controls of these items through completion of installation for 
an organization that does not have an ASME Certificate of 
Authorization. IWA-4131 in the 2019 Edition of the ASME Code, Section 
XI, has a restriction that fabrication (of parts) by the Owner or 
owner's contracted Repair/Replacement Organization (not possessing an 
ASME Certificate of Authorization) may occur only at the Owner's 
facility. The proposed condition would be consistent with IWA-4143 of 
the 2019 Edition of the ASME Code, Section XI, which allowed a Repair/
Replacement Organization with a quality assurance program that complies 
with IWA-4142 to fabricate parts, appurtenances, piping assemblies, and 
supports at the Owner's facilities without application of an ASME 
Stamp/Certification Mark.
    Therefore, the NRC is adding Sec.  50.55a(b)(2)(xlvi) to condition 
the provision of IWA-4143 of the 2021 Edition of the ASME Code, Section 
XI, by prohibiting a contracted Repair/Replacement Organization from 
fabricating a part off-site of the Owner's facility (e.g., vendor 
facility) without an ASME Certificate of Authorization and without 
applying an ASME Stamp/Certification Mark.
Section 50.55a(b)(2)(xlvii) Section XI Condition: Weld Overlay Design 
Crack Growth Analysis
    The NRC proposes to add Sec.  50.55a(b)(2)(xlvii) to require stress 
corrosion crack growth analysis of the weld overlay material in 
Nonmandatory Appendix Q of ASME Code, Section XI. In the 2021 Edition, 
a change was made to Subparagraph Q-3000(a) to specifically note that 
stress corrosion crack growth analysis is not required within the weld 
overlay material. While these overlay materials are expected to be more 
stress corrosion crack resistant, Article Q-2000 does not require all 
overlay materials to be impervious to potential cracking. If the 
licensee can justify that the material would not experience stress 
corrosion cracking growth expected over design life of the overlay, the 
licensee should document this conclusion in the design. The NRC 
therefore proposes this condition to require the analysis of a 
hypothetical flaw in determining the design and design life of a weld 
overlay under Nonmandatory Appendix Q.
Section 50.55a(b)(2)(xlviii) Section XI Condition: Analytical 
Evaluations of Degradation
    The NRC proposes to add Sec.  50.55a(b)(2)(xlviii) to require that 
analytical evaluations performed in accordance with IWB-3132.3 and IWC-
3132.3 be submitted to the NRC. The 2019 Edition of the ASME BPV Code, 
Section XI, IWB-3134, Review by Authorities, requires that 
``[a]nalytical evaluation of examination results as required by IWB-
3132.3 shall be submitted to the regulatory authority

[[Page 53390]]

having jurisdiction at the plant site.'' IWC-3125, Review by 
Authorities, requires that ``[t]he analytical evaluation of examination 
results as required by IWC-3122.3 shall be submitted to the regulatory 
authority having jurisdiction at the plant site.'' The 2021 Edition of 
the ASME Code, Section XI, eliminates the provisions of IWB-3134 and 
IWC-3125 in their entirety. The NRC finds that flaw evaluations provide 
significant regulatory information in the following areas: the 
condition of the degradation of the affected component, the cause of 
the degradation, operating experience, methodology used, performance 
monitoring, and regulatory oversight. For example, the flaw evaluation 
predicts the flaw size with growth during a certain time period. The 
final flaw size should not exceed the allowable flaw size, and the 
affected component would need to be inspected prior to the final flaw 
size exceeding the allowable flaw size. The NRC needs to monitor the 
safety of plant operation, considering the flaw may grow during the 
plant operation. The flaw evaluation provides key information for the 
NRC's oversight. Accordingly, the NRC proposes to add Sec.  
50.55a(b)(2)(xlviii) to retain the requirement from the 2019 Edition of 
the ASME BPV Code, Section XI, that analytical evaluations performed in 
accordance with IWB-3132.3 and IWC-3132.3 be submitted to the NRC.
Section 50.55a(b)(2)(xlix) Section XI Condition: Analytical Evaluations 
of Flaws in Cladding
    The NRC proposes to add Sec.  50.55a(b)(2)(xlix) to prohibit the 
use of IWB-3600(b)(1) in the 2021 Edition of ASME BPV Code, Section XI 
(Division 1), for the inlay and onlay that are subject to the augmented 
inspection requirements in paragraph (g)(6)(ii)(F) of this section.
    IWB-3600(b)(1) in the 2021 Edition of the Code addresses the 
provision that a flaw, which lies entirely in the cladding of Class 1 
components, need not be analytically evaluated. In the 2021 Edition of 
the Code, this provision has been relocated from IWB-3610 to IWB-3600. 
In the code editions and addenda prior to the 2021 Edition since the 
1988 Addenda, this provision in IWB-3610 for Class 1 vessels has not 
been applicable to the analytical evaluation for piping that is 
separately addressed in IWB-3640. Based on the relocation of the 
provision to IWB-3600, the 2021 Edition of the Code without a condition 
would allow that a flaw, which lies entirely in the cladding of piping, 
need not be analytically evaluated.
    In comparison, paragraph (g)(6)(ii)(F) of this section addresses 
the augmented inspection requirements for Class 1 pressurized water 
reactor (PWR) piping and vessel nozzle butt welds. As part of the 
requirements, paragraph (g)(6)(ii)(F)(7) of this section describes the 
examination evaluation and acceptance standards for the inlay and onlay 
of the butt welds. Specifically, the condition in the paragraph 
requires that, for Inspection Items G, H, J, and K of Code Case N-770, 
when applying the acceptance standards of IWB-3514 for planar flaws 
contained within the inlay or onlay, the thickness ``t'' in IWB-3514 be 
the thickness of the inlay or onlay.
    Accordingly, when a flaw lies entirely in the inlay or onlay 
subject to the augmented inspections in paragraph (g)(6)(ii)(F)(7) of 
this section, the flaw is required to be evaluated in accordance with 
IWB-3514 by using the thickness of the inlay or onlay as the thickness 
``t'' in IWB-3514. Based on paragraph (g)(6)(ii)(F)(7) of this section, 
if a flaw in the inlay or onlay is not acceptable in accordance with 
IWB-3514 as conditioned by the paragraph, analytical evaluation of the 
flaw must be performed in accordance with IWB-3600 or repair/
replacement activities must be performed in accordance with IWA-4000.
    As discussed above, the use of IWB-3600(b)(1) in the 2021 Edition 
of ASME BPV Code, Section XI (Division 1) for the inlay and onlay is 
not consistent with paragraph (g)(6)(ii)(F)(7) of this section and the 
related provisions of analytical evaluation that are specified in IWB-
3600 in the code editions and addenda prior to the 2021 Edition. 
Therefore, the NRC proposes to add a condition to prohibit the use of 
IWB-3600(b)(1) in the 2021 Edition of the Code for the inlay and onlay 
that are subject to the augmented inservice inspection requirements for 
Class 1 piping and nozzle dissimilar-metal butt welds in paragraph 
(g)(6)(ii)(F) of this section.
Section 50.55a(g)(6)(ii)(D)(9) Section XI Condition: Volumetric 
Qualifications
    The NRC proposes to add Sec.  50.55a(g)(6)(ii)(D)(9) to allow 
licensees the option to utilize Supplement 15 of Mandatory Appendix 
VIII in the 2021 Edition or later of Section XI, incorporated by 
reference in Sec.  50.55a, for volumetric qualification of examinations 
required by Table 1 of ASME Code Case N-729-6. The ASME Code in 
combination with the Electric Power Research Institute Nondestructive 
Evaluation Center developed expanded qualifications similar to other 
volumetric qualification requirements in Mandatory Appendix VIII to 
replace the requirements described in ASME Code Case N-729-6. The NRC 
found these qualification requirements acceptable, in addition to the 
current requirements of ASME Code Case N-729-6. Therefore, to reduce 
the burden of requiring an update to all programs immediately, the NRC 
is proposing a condition to allow either qualification program to be 
used. In future Sec.  50.55a rulemakings, in which N-729 is further 
revised or incorporated into the ASME Code, the NRC expects that the 
Supplement 15 requirements of Mandatory Appendix VIII will be required. 
Additionally, as licensees adopt the 2021 Edition or later as an ISI 
Code of Record for their ISI Interval, Supplement 15 of Mandatory 
Appendix VIII will be a requirement. The NRC expects that with this 
proposed transitional time, that has no immediate impact or burden, 
licensees will be able to update their programs as necessary in as 
efficient manner as possible.
Section 50.55a(g)(6)(ii)(F) Augmented ISI Requirements: Examination 
Requirements for Class 1 Piping and Nozzle Dissimilar-Metal Butt Welds
    The NRC proposes to update the requirements for the augmented 
inspection of dissimilar-metal butt welds in U.S. PWRs from ASME Code 
Case N-770-5 to N-770-7. This change will require condition Sec.  
50.55a(g)(6)(ii)(F)(1) to be updated, and condition Sec.  
50.55a(g)(6)(ii)(F)(8) to be modified to retain an inspection frequency 
for optimized butt welds consistent with ASME Code Case N-770-5.
    The NRC proposes to update NRC condition Sec.  
50.55a(g)(6)(ii)(F)(1) Implementation, by changing the reference of 
ASME Code Case N-770-5 to N-770-7. Additionally, the implementation 
requirement will be changed from no later than one year after June 3, 
2020, to no later than one year after the rule effective date.
    The NRC proposes to modify the existing condition Sec.  
50.55a(g)(6)(ii)(F)(8) to retain, in part, the volumetric examination 
frequency of ASME Code Case N-770-5, which was changed in N-770-6. In 
N-770-5, the Frequency of Examination for Inspection Item C-2 welds 
(uncracked butt welds reinforced by optimized weld overlay of Alloy 52/
152 material) is ``100% of these welds shall be examined once each 
inspection interval. For any overlays that have an analyzed life of 
less than 10 [years], the inspection interval shall be less than or 
equal to the analyzed life.''
    In N-770-5, the Frequency of Examination for Inspection Item F-2

[[Page 53391]]

welds (cracked butt weld reinforced by optimized weld overlay of Alloy 
52/152 material) is ``[o]nce during the first or second refueling 
outage following overlay. Examination volumes that show no indication 
of crack growth or new cracking shall be examined once each inspection 
interval. For any overlays that have an analyzed life of less than 10 
years, the inspection interval shall be less than or equal to the 
analyzed life.''
    The current NRC condition Sec.  50.55a(g)(6)(ii)(F)(8) states, 
``[i]nitial inservice examination of Inspection Item C-2 welds shall be 
performed between the third refueling outage and no later than 10 years 
after application of the overlay.'' In N-770-7, the Frequency of 
Examination for Inspection Item C-2 welds is--

[e]xamine all welds no sooner than the third refueling outage and no 
later than 10 years following optimized weld overlay. After the 
first interval, examination volumes that show no indication of 
cracking shall be placed into a population to be examined on a 
sample basis. Twenty-five percent of this population shall be added 
to the ISI Program in accordance with -2410 and shall be examined 
once each inspection interval [Note (10)]. For any optimized weld 
overlays that have an analyzed life of less than 10 years, the 
inspection interval shall be less than or equal to the analyzed 
life.

    In N-770-7, the Frequency of Examination for Inspection Item F-2 
welds is--

[o]nce during the first or second refueling outage following 
optimized weld overlay. Weld overlay examination volumes that show 
no indication of crack growth or new cracking shall be placed into a 
population to be examined on a sample basis. Twenty-five percent of 
this population shall be added to the ISI Program in accordance with 
-2410 and shall be examined once each inspection interval [Note 
(10)]. For any optimized weld overlays that have an analyzed life of 
less than 10 years, the inspection interval shall be less than or 
equal to the analyzed life.

    The NRC continues to find that the long-term frequency for 
examination of optimized weld overlays shall be 100 percent of the 
welds each inspection interval, consistent with N-770-5 and the current 
regulation. Optimized weld overlays still structurally rely upon 25 
percent of the primary water stress corrosion cracking material of the 
original butt weld to provide structural integrity for the weld. 
Further, the deposition of a more crack-resistant material such as 
Alloy 52/152 acts as a crack growth restriction, allowing growth along 
the susceptible original weld material rather than through the more 
crack resistant material that would provide leakage as a defense-in-
depth measure to identify cracking. A 25-percent sample inspection 
could allow optimized weld overlayed welds to have cracks develop into 
the structural retaining material of an ASME Class 1 butt weld in the 
reactor coolant system. This condition is not true of full structural 
weld overlays, which the NRC has found can utilize a long-term 
examination frequency of a 25-percent sample. Because the design of the 
optimized weld overlay reduces the effectiveness of the defense-in-
depth leak initiation method of identifying potential cracking, a 
volumetric examination of each weld is required to provide reasonable 
assurance of structural integrity for these optimized weld overlays. 
Therefore, the NRC is modifying the condition to state that after 
initial examination for Inspection Items C-2 and F-2 welds, optimized 
weld overlay examination volumes that show no indication of crack 
growth or new cracking shall be examined once each inspection interval.
    ASME Code Case N-770-7 also creates a new Inspection Item category 
for auxiliary head adapter (AHA) butt welds, B-3. Some Westinghouse 4-
loop plants have AHA butt welds connected to the upper reactor vessel 
closure head. The new Inspection Item B-3 caries the same inspection 
requirements of B-1, which the AHA butt welds fall under currently. The 
update to a new Inspection Item category was made to facilitate a 
change to the scope expansion requirements in the event that a crack 
was found in an AHA butt weld.
    The purpose of a scope expansion examination is if a crack is found 
in one weld, examinations of similar welds should be performed to 
ensure no generic issues are identified with that type of location or 
operating condition. The Inspection Item category that AHA butt welds 
currently fall under, B-1, could trigger scope expansion examinations 
in any, and potentially all, unmitigated reactor coolant system welds. 
The AHA butt welds are approximately 6-inches in diameter and are 
located on top of the reactor pressure vessel head in a low or no flow 
area. This location, while being of the same weld material, is not 
generally operating under the same conditions as the rest of the 
reactor coolant butt welds in the primary system of a Westinghouse PWR. 
Therefore, the ASME Code revised Code Case N-770 in revision 7 to 
include the new category and modify the scope expansion rules to 
reflect this change. The NRC agrees with the change to address the 
intent of scope expansion if a flaw were to be identified in an AHA 
butt weld. Therefore, the NRC is proposing to update the augmented 
inservice inspection requirements of Sec.  50.55a(g)(6)(ii)(F)(1) to 
mandate the use of N-770-7 in lieu of N-770-5.

C. ASME OM Code

Section 50.55a(a)(1)(iv), ASME Operation and Maintenance Code
    The NRC proposes to amend the regulations in Sec.  
50.55a(a)(1)(iv)(C) to incorporate by reference the 2022 Edition of the 
ASME OM Code for nuclear power plants. The NRC is streamlining Sec.  
50.55a wherever possible to provide clearer IST regulatory requirements 
for nuclear power plant licensees and applicants. In the following 
paragraphs, the NRC includes certain proposed changes that are part of 
the Sec.  50.55a streamlining efforts.
Section 50.55a(b)(3)(ii) OM Condition: Motor-Operated Valve (MOV) 
Testing
    The NRC proposes to modify Sec.  50.55a(b)(3)(ii) by removing 
conditions (A), (B), and (C) where licensees are implementing the 2022 
Edition of the ASME OM Code as incorporated by reference in Sec.  
50.55a, because Appendix III, ``Preservice and Inservice Testing of 
Active Electric MOV Assemblies in Water-Cooled Reactor Nuclear Power 
Plants,'' to the 2022 Edition of the ASME OM Code appropriately 
incorporates the requirements specified in those conditions. Condition 
(D) has not been incorporated into the 2022 Edition of the ASME OM 
Code. Therefore, condition (D) in Sec.  50.55a(b)(3)(ii) will continue 
to apply to all editions and addenda of the ASME OM Code incorporated 
by reference in Sec.  50.55a.
Section 50.55a(b)(3)(iii) OM Condition: Check Valves
    The NRC proposes to revise Sec.  50.55a(b)(3)(iii) by removing 
condition (B), ``Check valves,'' which states that licensees must 
perform bi-directional testing of check valves within the IST program 
where practicable. New reactors are applying more recent editions of 
the ASME OM Code that require bi-directional testing of check valves. 
Therefore, condition (B) is not needed in Sec.  50.55a(b)(3)(iii). The 
NRC proposes to reserve condition (B) in Sec.  50.55a(b)(3)(iii) for 
possible future use.
Section 50.55a(b)(3)(iii) OM Condition: Flow-Induced Vibration
    The NRC proposes to revise Sec.  50.55a(b)(3)(iii) by removing 
condition (C), ``Flow-induced vibration,'' which states that licensees 
shall monitor flow-induced vibration from hydrodynamic loads and 
acoustic resonance during preservice testing or inservice testing to

[[Page 53392]]

identify potential adverse flow effects on components within the scope 
of the IST program. Based on regulatory experience with new reactor 
licensing, the NRC considers that flow-induced vibration is 
appropriately addressed during the licensing phase and initial testing 
program at each new reactor nuclear power plant. Therefore, condition 
(C) is not needed in Sec.  50.55a(b)(3)(iii). The NRC proposes to 
reserve paragraph (C) in Sec.  50.55a(b)(3)(iii) for possible future 
use.
Section 50.55a(b)(3)(vii) OM Condition: Snubber Visual Examination 
Interval Extension
    The NRC proposes to add Sec.  50.55a(b)(3)(vii) to clarify use of 
ASME OM Code, Subsection ISTD, ``Preservice and Inservice Requirements 
for Dynamic Restraints (Snubbers) in Water-Cooled Reactor Nuclear Power 
Plants,'' paragraph ISTD-4253, ``Additional Requirements for 10-year 
Interval,'' and Note 7 of the Table ISTD-4252-1, ``Visual Examination 
Table,'' with ASME OM Code Case OMN-15, Revision 2, ``Performance-Based 
Requirements for Extending the Snubber Operational Readiness Testing 
Interval at LWR Power Plants.'' OM Code Case OMN-15, Revision 2, 
Section 3.4, ``Code Case OMN-13,'' states that ``this Code Case [OMN-
15] shall not be used in conjunction with Code Case OMN-13, 
`Performance-Based Requirements for Extending Snubber Inservice Visual 
Examination Interval at LWR Power Plants.' '' OM Code Case OMN-13 is 
incorporated in paragraph ISTD-4253 and Note 7 of Table ISTD-4252-1 of 
the 2022 Edition of the ASME OM Code. The use of OM Code Case OMN-13 is 
prohibited in conjunction with the use of OM Code Case OMN-15. However, 
the specific language of paragraph ISTD-4253 and Note 7 of Table ISTD-
4252-1 does not clarify that the use of paragraph ISTD-4253 and Note 7 
of Table ISTD-4252-1 is optional. The NRC proposes to clarify the 
language in the ASME OM Code by stating that when implementing 
Subsection ISTD, paragraph ISTD-4253, and Note 7 of Table ISTD-4252-1, 
in the 2022 Edition of the ASME OM Code, incorporated by reference in 
paragraph (a)(1)(iv) of this section, to extend snubber visual 
examination beyond two refueling cycles (48 months), the licensee is 
prohibited from applying OM Code Case OMN-15, Revision 2.
Section 50.55a(b)(3)(x) OM Condition: Class 1 Pressure Relief Valve 
Sample Expansion
    The NRC proposes to add Sec.  50.55a(b)(3)(x) to clarify 
subparagraph (1) in paragraph (c), Requirements for Testing Additional 
Valves, of Section I-1320, ``Test Frequencies, Class 1 Pressure Relief 
Valves,'' in the ASME OM Code, Appendix I, ``Inservice Testing of 
Pressure Relief Devices in Water-Cooled Reactor Nuclear Power Plants,'' 
which states that for each valve tested for which the as-found set-
pressure (first test actuation) exceeds the greater of either the plus/
minus tolerance limit of the Owner-established set-pressure acceptance 
criteria of I-1310(e) or 3 percent of valve nameplate set-
pressure, two additional valves shall be tested from the same valve 
group. The expansion of the test sample provides reasonable assurance 
that a degradation mechanism that might cause multiple Class 1 Pressure 
Relief Valves to be incapable of performing their safety functions will 
be identified. Typically, it is expected that variations in actual 
valve performance will result in an Owner-established set-pressure 
acceptance criteria for Class 1 Pressure Relief Valves exceeding the 
default 3-percent valve nameplate set-pressure. The NRC has no concerns 
with the language of paragraph I-1320(c)(1) where the Owner-established 
set-pressure acceptance criteria are greater than the 3-percent default 
value. Based on plant-specific valve performance, the Owner might need 
to establish set-pressure acceptance criteria for Class 1 Pressure 
Relief Valves lower than the default 3-percent value. The failure of a 
Class 1 Pressure Relief Valve to meet the Owner-established set-
pressure acceptance criteria can signify that the valve is incapable of 
performing its safety function. In such cases, it is important to 
determine whether other Class 1 Pressure Relief Valves also have 
performance problems that could cause them to be unable to perform 
their safety functions. However, the specific language of paragraph I-
1320(c)(1) might be interpreted to not require an expansion of the test 
sample where the default 3-percent value is greater than the Owner-
established set-pressure acceptance criteria. This might lead in an 
unsafe situation where the licensee is unaware that multiple Class 1 
Pressure Relief Valves are incapable of performing their safety 
functions. To resolve this concern, the NRC proposes to clarify 
paragraph I-1320(c)(1) to be read that for each valve tested for which 
the as-found set-pressure (first test actuation) exceeds the plus/minus 
tolerance limit of the Owner-established design set-pressure acceptance 
criteria of I-1310(e), or 3 percent of valve nameplate set-
pressure if the Owner has not established design set-pressure 
acceptance criteria, two additional valves shall be tested from the 
same valve group. The specification of Owner-established ``design'' 
set-pressure acceptance criteria allows the licensee to establish 
specific criteria for testing purposes.

D. Editorial Correction

Section 50.55a(d) Quality Group B Components
    The NRC proposes to make an editorial correction to Sec.  
50.55a(d), ``Quality Group B components,'' by replacing the colon at 
the end of the second sentence of the introductory paragraph with a 
period. When the introductory paragraph of Sec.  50.55a(d) was expanded 
to include a reference to 10 CFR part 52, the new second sentence of 
the introductory paragraph incorrectly placed a colon at the end of the 
sentence rather than a period. The use of a colon implies that items 
(1) and (2) in Sec.  50.55a(d) only apply to 10 CFR part 52 plants. 
However, item (1) of Sec.  50.55a(d) specifies a requirement for 
applicants under 10 CFR part 50.

IV. Specific Requests for Comments

    In the 2021 Edition of the ASME Code, Section XI, ASME removed the 
IWB-3134 and IWC-3125 requirements for nuclear plant owners to submit 
analytical evaluations to the regulatory authority having jurisdiction 
at the plant site. The NRC proposes to condition the 2021 Edition of 
the ASME Code, Section XI to require that such evaluations be submitted 
to the NRC, maintaining the status quo for U.S. plants. The analytical 
evaluation reports provide the NRC with a tool to efficiently inspect 
and validate flaws identified by a licensee and the activities to 
address them (e.g., analysis for continued operation or repair/
replacement). Furthermore, the reports provide the NRC with valuable 
operating experience data to monitor degradation trends across the 
industry to ensure public health and safety. There are other similar 
reporting requirements in Sec.  50.55a, including Sec.  
50.55a(b)(2)(xxxii), Sec.  50.55a(b)(2)(xliii), and Sec.  
50.55a(g)(6)(ii)(F)(6). The NRC is seeking advice and recommendations 
from the public on the proposed condition and the related requirements 
to ascertain their perceived value. We are particularly interested in 
comments and supporting rationale from the public on the following:
    (1) What alternative means are there for the NRC to accomplish the 
goal of monitoring degradation trends such that the NRC could remove 
the condition?

[[Page 53393]]

    (2) How can the NRC effectively leverage the information provided 
in flaw evaluations and associated component degradation in a way that 
is transparent to stakeholders and ensures structural integrity of 
nuclear components without incurring excessive administrative burden 
for plant owners?

V. Section-by-Section Analysis

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

    This proposed rule would revise paragraphs (a)(1)(i)(E)(19) and 
(20) and add new paragraph (a)(1)(i)(E)(21) to include the 2021 Edition 
of the ASME BPV Code.

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

    This proposed rule would revise paragraphs (a)(1)(ii)(C)(55) and 
(56) and add new paragraph (a)(1)(ii)(C)(57) to include the 2021 
Edition.

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

    This proposed rule would revise paragraph (a)(1)(iii)(D) to update 
ASME BPV Code Case N-770-5 to N-770-7 and to update the approval date 
to December 4, 2020.

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

    This proposed rule would revise paragraph (a)(1)(iv)(C) to add the 
2022 Edition of the ASME OM Code.

Paragraph (b)(1)(iv)

    This proposed rule would revise and redesignate existing paragraph 
(b)(1)(iv) as paragraph (b)(1)(iv) introductory text, add new 
paragraphs (b)(1)(iv)(A) and (B), and remove and reserve paragraph 
(b)(1)(iv)(B).

Paragraph (b)(1)(vi)

    This proposed rule would revise paragraph (b)(1)(vi) to revise 
``sleeves'' to ``sheaths'' and add a new sentence that this condition 
is not applicable to 2015 and later Editions.

Paragraph (b)(1)(xi)

    This proposed rule would revise the introductory text to paragraph 
(b)(1)(xi) to clarify the applicable conditions and add two new 
conditions specific to polyethylene pressure piping when applying the 
2015 through 2021 Editions. The proposed rule also would revise 
paragraph (b)(1)(xi)(B) to add the 2015 to 2021 Editions of BPV Code 
Section III.

Paragraph (b)(1)(xiii)

    This proposed rule would revise the introductory text to paragraph 
(b)(1)(xiii) and paragraphs (b)(1)(xiii)(A) and (B) to update the 
applicability of the latest edition and addenda incorporated by 
reference in Sec.  50.55a(a)(1).

Paragraph (b)(1)(xiv)

    This proposed rule would add new paragraph (b)(1)(xiv) to require 
that Nonmandatory Appendix NN be used in its entirety.

Paragraph (b)(2)

    This proposed rule would revise the introductory text of paragraph 
(b)(2) to refer the applicability to users of the editions incorporated 
by reference in paragraph (a)(1)(ii).

Paragraph (b)(2)(viii)

    This proposed rule would revise paragraph (b)(2)(viii) to update 
the applicability of paragraphs (b)(2)(viii)(H) and (b)(2)(viii)(I) 
through the 2019 Edition.

Paragraph (b)(2)(ix)

    This proposed rule would revise paragraph (b)(2)(ix) to update the 
applicability of paragraph (b)(2)(ix)(A)(2).

Paragraph (b)(2)(xv)

    This proposed rule would eliminate this condition at paragraph 
(b)(2)(xv).

Paragraph (b)(2)(xxxiv)

    This proposed rule would revise the introductory text to paragraph 
(b)(2)(xxxiv), leaving only the heading; revise paragraph 
(b)(2)(xxxiv)(A) and add new paragraphs (b)(2)(xxxiv)(A)(1) and (B)(1) 
to update the version of ASME BPV Code Case N-513 to the latest version 
currently approved in RG 1.147; and revise paragraph (b)(2)(xxxiv)(B) 
to prohibit the use of Nonmandatory Appendix U, Supplement U-S1 in the 
2021 Edition of Section XI.

Paragraph (b)(2)(xliv)

    This proposed rule would add new paragraph (b)(2)(xliv) to prohibit 
the use of Y-2200, Y-2440, and Y-3200 in the 2021 Edition of Section 
XI.

Paragraph (b)(2)(xlv)

    This proposed rule would add new paragraph (b)(2)(xlv) to condition 
the provision of IWA-4540(a) and (e) of the 2021 Edition of the ASME 
Code, Section XI, to require that a VT-2 examination of the area 
affected by the repair/replacement activity be conducted during the 
Type C test in appendix J to this part.

Paragraph (b)(2)(xlvi)

    This proposed rule would add new paragraph (b)(2)(xlvi) to prohibit 
a contracted Repair/Replacement Organization without an ASME 
Certificate of Authorization that does not apply an ASME Stamp/
Certification Mark from fabricating ASME Code, Section III parts, 
appurtenances, piping subassemblies, and supports offsite of the 
Owner's facility (e.g., vendor facility) when applying the provisions 
of IWA-4143 in the 2021 Edition of the ASME Code, Section XI.

Paragraph (b)(2)(xlvii)

    This proposed rule would add new paragraph (b)(2)(xlvii) to require 
stress corrosion crack growth analysis of the weld overlay material 
under subparagraph Q-3000(a) of Nonmandatory Appendix Q in the 2021 
Edition of the ASME Code, Section XI.

Paragraph (b)(2)(xlviii)

    This proposed rule would add new paragraph (b)(2)(xlviii) to 
require that analytical evaluations performed in accordance with IWB-
3132.3 and IWC-3132.3 be submitted to the NRC.

Paragraph (b)(2)(xlix)

    This proposed rule would add paragraph (b)(2)(xlix) to prohibit the 
use of IWB-3600(b)(1) in the 2021 Edition of ASME BPV Code, Section XI 
(Division 1) for the inlay and onlay that are subject to the augmented 
inspection requirements in paragraph (g)(6)(ii)(F).

Paragraph (b)(3)(ii)

    This proposed rule would revise the introductory text to paragraph 
(b)(3)(ii) to exclude conditions (A), (B) and (C) from being applicable 
to the 2022 Edition of the ASME OM Code because those conditions have 
been incorporated into that edition of the ASME OM Code.

Paragraph (b)(3)(iii)

    This proposed rule would revise paragraph (b)(3)(iii) to remove and 
reserve for future use the conditions in paragraphs (b)(3)(iii)(B) and 
(C) because those conditions are required by other regulations for new 
reactors.

Paragraph (b)(3)(vii)

    This proposed rule would replace reserved paragraph (b)(3)(vii) 
with a new condition on ASME OM Code, Subsection ISTD, paragraph ISTD-
4253, and Note 7 of the Table ISTD-4252-1 related to snubbers to be 
consistent with the accepted provisions in OM Code Case OMN-15.

Paragraph (b)(3)(x)

    This proposed rule would create a new paragraph (b)(3)(x) to 
clarify the requirement for expanding the test sample for Class 1 
Pressure Relief Valves specified in ASME OM Code, Appendix I, paragraph 
I-1320(c)(1).

[[Page 53394]]

Paragraph (d)

    This proposed rule would revise the introductory text of paragraph 
(d) by correcting an editorial error. The colon would be replaced with 
a period, at the end of the second sentence.

Paragraph (g)(6)(ii)(D)(9)

    This proposed rule would add new paragraph (g)(6)(ii)(D)(9) to 
allow licensees the option to utilize Supplement 15 of Mandatory 
Appendix VIII, in the 2021 Edition or later of Section XI incorporated 
by reference in Sec.  50.55a, for volumetric qualification of 
examinations required by Table 1 of ASME Code Case N-729-6.

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

    This proposed rule would revise paragraph (g)(6)(ii)(F)(1) to 
update the requirements for the augmented inspection of dissimilar-
metal butt welds in U.S. PWRs from ASME Code Case N-770-5 to N-770-7 
and to update the dates to conform with this proposed rule.

Paragraph (g)(6)(ii)(F)(8)

    This proposed rule would modify the existing condition in paragraph 
(g)(6)(ii)(F)(8) to retain, in part, the volumetric examination 
frequency of ASME Code Case N-770-5, which was changed in N-770-6.

VI. Regulatory Flexibility Certification

    As required by the Regulatory Flexibility Act of 1980, 5 U.S.C. 
605(b), the NRC certifies that this rule, if adopted, will not have a 
significant economic impact on a substantial number of small entities. 
This proposed 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 
(10 CFR 2.810).

VII. Regulatory Analysis

    The NRC has prepared a draft regulatory analysis on this proposed 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the NRC. The NRC requests public comment on 
the draft regulatory analysis. The regulatory analysis is available as 
indicated in the ``Availability of Documents'' section of this 
document. Comments on the draft analysis may be submitted to the NRC as 
indicated under the ADDRESSES caption of this document.

VIII. 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, examine, and repair or replace 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 Class 1, 2, and 3 pumps and valves in accordance with 
the rules provided in the ASME OM Code.
     Inspect, examine, repair or replace, and test Class 1, 2, 
and 3 dynamic restraints (snubbers) in accordance with the rules 
provided in either the ASME OM Code or Section XI, depending on the 
Code Edition.
    This rulemaking proposes to incorporate by reference the 2021 
Edition of the ASME BPV Code, Section III, Division 1, and ASME BPV 
Code, Section XI, Division 1, as well as the 2022 Edition of the ASME 
OM Code.
    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. Therefore, the 
NRC finds 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 or combined license, 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. 
Therefore, 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 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 must periodically update their ISI and IST 
programs to the latest edition 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 code of record interval. Therefore, 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 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

[[Page 53395]]

requirements. However, the NRC explains any such exceptions to the Code 
in the preamble to 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 rules.
    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: Proposed 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 
proposed changes to Sec.  50.55a that go beyond the minimum changes 
necessary and required to adopt the new ASME Code edition into Sec.  
50.55a.

ASME BPV Code, Section III

    1. Revise Sec.  50.55a(b)(1)(iv) to not approve Subpart 2.19 in 
NQA-1-17, NQA-1-19 and NQA-1-22 for use. This proposed revision 
clarifies current requirements and is considered to be consistent with 
the meaning and intent of current requirements. The proposed condition 
does not constitute a new or changed NRC position. Therefore, this 
proposed condition is not a backfit.
    2. Revise Sec.  50.55a(b)(1)(vi) to change the word sleeves to 
sheaths and to note that this condition is not applicable to 2015 and 
later Editions. This condition is not applicable to 2015 and later 
Editions as Subsection NH is deleted from Section III Division 1. The 
revisions to clarify a word and clarification of Code Edition 
applicability do not constitute a change in NRC position. Therefore, 
this is not a backfit.
    3. Revise Sec.  50.55a(b)(1)(xi) to revise this condition regarding 
the applicability to specific Code editions. 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 first provision, as noted in 
50.55a(b)(1)(xi)(A). When applying the 2015 through 2021 Editions of 
Section III, Mandatory Appendix XXVI, ``Rules for Construction of Class 
3 Buried Polyethylene Pressure Piping,'' applicants or licensees must 
meet the second provision, as noted in 50.55a(b)(1)(xi)(B). When 
applying the 2017 Edition of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the third provision, as 
noted in 50.55a(b)(1)(xi)(C). The revision is only for Code editions 
applicability and does not constitute a new or changed NRC position. 
Therefore, this change is not a backfit.
    4. Revise Sec.  50.55a(b)(1)(xiii) including the first provision, 
Sec.  50.55a(b)(1)(xiii)(A), and second provision, Sec.  
50.55a(b)(1)(xiii)(B), to extend the applicability of the conditions 
through the latest edition of the ASME BPV Code, Section III 
incorporated by reference in paragraph (a)(1)(i). The NRC is proposing 
to revise this condition to apply to the latest edition incorporated by 
reference, which is not a change to NRC position and, therefore, is not 
a backfit.
    5. Add Sec.  50.55a(b)(1)(xiv) to condition the use of the 
provisions of NCA-8151, NCA-8500, and Nonmandatory Appendix NN in the 
2021 Edition of Section III, to require that when Nonmandatory Appendix 
NN is used for the elimination of surface defects and repairs of 
stamped components prior to the completion of Form N-3 Data Report, all 
applicable requirements of Nonmandatory Appendix NN shall be met. The 
proposed condition on Nonmandatory Appendix NN does not constitute a 
new or changed NRC position. Therefore, the addition of this proposed 
condition is not a backfit.

ASME BPV Code, Section XI

    1. Revise Sec.  50.55a(b)(2)(viii), to remove the applicability of 
Sec.  50.55a(b)(2)(viii)(H) and (I) from the 2021 Edition. These 
changes to Sec.  50.55a(b)(2)(viii) remove conditions that were 
incorporated in the 2021 Edition. Therefore, this change is not a 
backfit.
    2. Revise Sec.  50.55a(b)(2)(ix), to remove the applicability of 
Sec.  50.55a(b)(2)(ix)(A)(2) from the 2021 Edition. This change to 
Sec.  50.55a(b)(2)(ix) removes a condition that was incorporated into 
the 2021 Edition. Therefore, this change is not a backfit.
    3. Remove and reserve Sec.  50.55a(b)(2)(xv). This condition is 
applicable to older Editions of Section XI that are no longer in use by 
licensees. Removing this condition does not modify current licensee 
inservice inspection requirements and, therefore, is not a backfit.
    4. Revise Sec.  50.55a(b)(2)(xxxiv)(A) to modify the cited version 
of ASME Code Case N-513 to the latest version approved in RG 1.147. The 
revised condition is renumbered Sec.  50.55a(b)(2)(xxxiv)(A)(2). There 
is no change to the requirements and therefore, this revision is not a 
backfit.
    5. Add Sec.  50.55a(b)(2)(xxxiv)(B) to prohibit the use of 
Nonmandatory Appendix U, Supplement U-S1. Supplement U-S1 of 
Nonmandatory Appendix U is obsolete relative to Code Case N-513, as 
included in the latest revision of RG 1.147 incorporated by reference 
in Sec.  50.55a(a)(3)(ii). Licensees have adopted the updated rules in 
Code Case N-513 for temporary acceptance of flaws in moderate energy 
Class 2 and 3 piping. This revision does not modify the current 
inservice inspection regulatory requirements and, therefore, is not a 
backfit.
    6. Add Sec.  50.55a(b)(2)(xliv) to prohibit the use of Article Y-
2200, Subarticle Y-2440, and Article Y-3200 in Nonmandatory Appendix Y. 
These articles have corresponding Code Cases,

[[Page 53396]]

which have been included in the latest revision of RG 1.147 
incorporated by reference in Sec.  50.55a(a)(3)(ii). Licensees have 
adopted the crack growth laws in the corresponding Code Cases: Cases N-
809, N-889, and N-643, respectively. The proposed condition on 
Nonmandatory Appendix Y does not constitute a new or changed NRC 
position. Therefore, the addition of this proposed condition is not a 
backfit.
    7. Add Sec.  50.55a(b)(2)(xlv) to condition the provision of IWA-
4540(a) and (e) of the 2021 Edition of the ASME Code, Section XI, to 
require that a VT-2 examination be performed of the area affected by 
the repair/replacement activity during the Type C test in appendix J to 
10 CFR part 50. The proposed condition on IWA-4540(a) and (e) does not 
constitute a new or changed NRC position. Therefore, the addition of 
this proposed condition is not a backfit.
    8. Add Sec.  50.55a(b)(2)(xlvi) to condition the provision of IWA-
4143 of the 2021 Edition of the ASME Code, Section XI, by prohibiting a 
contracted Repair/Replacement Organization from fabricating a part 
offsite of the Owner's facility (e.g., vendor facility) without an ASME 
Certificate of Authorization and without applying an ASME Stamp/
Certification Mark. The proposed condition on IWA-4143 does not 
constitute a new or changed NRC position. Therefore, the addition of 
this proposed condition is not a backfit.
    9. Add Sec.  50.55a(b)(2)(xlvii) to prevent a new exemption in the 
2021 Edition of subparagraph Q-3000(a) of the requirement to remove 
stress corrosion crack growth analysis of the overlay material. This is 
a new condition that retains the previous requirements and allowances 
of the previous approved version of Nonmandatory Appendix Q, and 
accordingly, is not a new or changed position. Therefore, the addition 
of this proposed condition is not a backfit.
    10. Add Sec.  50.55a(b)(2)(xlviii) to require submission of 
analytical evaluations performed under IWB-3132.3 and IWC-3122.3 to the 
NRC. This is a new condition that retains the requirements of the 
previous approved version of Section XI, and accordingly, is not a new 
or changed position. Therefore, the addition of this proposed condition 
is not a backfit.
    11. Add 10 CFR 50.55a(b)(2)(xlix) to prohibit the use of IWB-
3600(b)(1) in the 2021 Edition of the Code for the inlay and onlay that 
are subject to the augmented inspections specified in paragraph 
(g)(6)(ii)(F) of this section. The proposed condition on the analytical 
evaluation of a flaw in the inlay or onlay does not constitute a new or 
changed NRC position. Therefore, the addition of this proposed 
condition is not a backfit.
    12. Add Sec.  50.55a(g)(6)(ii)(D)(9) to allow licensees the option 
to utilize Supplement 15 of Mandatory Appendix VIII in the 2021 Edition 
or later of Section XI, incorporated by reference in Sec.  50.55a, for 
volumetric qualification of examinations required by Table 1 of ASME 
Code Case N-729-6. Providing licensees the option of using either the 
qualification program in ASME Code Case N-729-6 or Supplement 15 of 
Mandatory Appendix VIII does not constitute a new or changed NRC 
position. No backfit is implied with the option to allow a new 
volumetric qualification option for licensees to utilize. No increase 
in requirements is expected.
    13. Modify 50.55a(a)(1)(iii)(D) and 50.55a(g)(6)(ii)(F) to update 
the requirements for the augmented inspection of dissimilar-metal butt 
welds in U.S. PWRs from ASME Code Case N-770-5 to N-770-7. This change 
will require one condition to be updated, Sec.  50.55a(g)(6)(ii)(F)(1), 
and one condition modified to retain an inspection frequency for 
optimized butt welds consistent with ASME Code Case N-770-5. The 
current regulatory requirements for the examination frequency of 
Inspection Items C-2 and F-2 welds have not changed. The change in 
examination categorization for B-3 provides no change to inspection 
frequency or requirements. The change in scope expansion requirements 
is a reduction in the requirements if a flaw is identified in an AHA 
butt weld consistent with the regulatory purpose of examination scope 
expansion. Therefore, the update and modification of previous 
conditions are not backfits.

ASME OM Code

    1. Revise Sec.  50.55a(b)(3)(ii) by removing conditions (A), (B), 
and (C) where licensees are implementing the 2022 Edition of the ASME 
OM Code as incorporated by reference in Sec.  50.55a, because Appendix 
III to the 2022 Edition of the ASME OM Code appropriately incorporates 
the requirements specified in those conditions. The revisions do not 
modify the current IST regulatory requirements and, therefore, are not 
backfits.
    2. Delete condition (B) in Sec.  50.55a(b)(3)(iii), which states 
that licensees of new reactors must perform bi-directional testing of 
check valves within the IST program where practicable. The licensees of 
new reactors are required to apply more recent editions of the ASME OM 
Code that require bi-directional testing of check valves. Therefore, 
condition (B) is not needed in Sec.  50.55a(b)(3)(iii). This change 
does not modify the current IST regulatory requirements and, therefore, 
is not a backfit.
    3. Delete condition (C) in Sec.  50.55a(b)(3)(iii), which states 
that licensees of new reactors shall monitor flow-induced vibration 
from hydrodynamic loads and acoustic resonance during preservice 
testing or inservice testing to identify potential adverse flow effects 
on components within the scope of the IST program. Based on regulatory 
experience with new reactor licensing, the NRC considers that flow-
induced vibration is appropriately addressed during the licensing phase 
and initial testing program at each new reactor nuclear power plant. 
Therefore, condition (C) is not needed in Sec.  50.55a(b)(3)(iii). This 
change does not modify the current IST regulatory requirements and, 
therefore, is not a backfit.
    4. Create a new Sec.  50.55a(b)(3)(vii) to clarify use of ASME OM 
Code, Subsection ISTD, paragraph ISTD-4253, and Note 7 of the Table 
ISTD-4252-1, with the ASME OM Code Case OMN-15, Revision 2. This 
modification reflects a clarification of ASME OM Code, Subsection ISTD, 
paragraph ISTD-4253 and Table ISTD-4252-1, is not a new or changed NRC 
position, and therefore, is not a backfit.
    5. Create a new Sec.  50.55a(b)(3)(x) to clarify ASME OM Code, 
Appendix I, paragraph I-1320(c)(1), which states that for each valve 
tested for which the as-found set-pressure (first test actuation) 
exceeds the greater of either the plus/minus tolerance limit of the 
Owner-established design set-pressure acceptance criteria of paragraph 
I-1310(e) or 3 percent of valve nameplate set-pressure, two 
additional valves shall be tested from the same valve group. The 
expansion of the test sample provides reasonable assurance that a 
degradation mechanism that might cause multiple Class 1 Pressure Relief 
Valves to be incapable of performing their safety functions will be 
identified. However, the specific language of paragraph I-1320(c)(1) 
might be interpreted to not require an expansion of the test sample 
where the default 3-percent value is greater than the Owner-established 
set-pressure acceptance criteria. This modification reflects a 
clarification of ASME OM Code, Appendix I, paragraph I-1320(c)(1), is 
not a new or changed NRC position, and, therefore, is not a backfit.

[[Page 53397]]

ASME Editorial Correction

    1. Replace the colon at the end of the second sentence of the 
introductory paragraph of Sec.  50.55a(d) with a period. This is an 
editorial correction and, therefore, not a backfit.

Conclusion

    The NRC finds that incorporation by reference into Sec.  50.55a of 
the 2021 Edition of Section III, Division 1, of the ASME BPV Code 
subject to the identified conditions; the 2021 Edition of Section XI, 
Division 1, of the ASME BPV Code, subject to the identified conditions; 
and the 2022 Edition of the ASME OM Code subject to the identified 
conditions, does not constitute backfitting or represent an 
inconsistency with any issue finality provisions in 10 CFR part 52.

IX. Generic Aging Lessons Learned Report

Background

    In December 2010, the NRC issued ``Generic Aging Lessons Learned 
(GALL) Report,'' NUREG-1801, Revision 2 (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, ``Standard 
Review Plan for Review of License Renewal Applications for Nuclear 
Power Plants,'' NUREG-1800, Revision 2 (ML103490036), was issued in 
December 2010, to ensure the quality and uniformity of NRC reviews of 
license renewal applications and to present a well-defined basis on 
which the NRC evaluates the applicant's AMPs 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 (ML11116A062), which describes 
the technical bases for the changes in Revision 2 of the GALL Report 
and Revision 2 of the standard review plan (SRP) for review of license 
renewal applications.
    Revision 2 of the GALL Report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3, 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 found that the 2009 Addenda 
through the 2017 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, are acceptable for the AMPs in the GALL 
Report. In a final rule issued on May 4, 2020 (85 FR 26540), the NRC 
further found that Subsections IWB, IWC, IWD, IWE, IWF, or IWL of 
Section XI of the 2015 Edition and the 2017 Edition of the ASME BPV 
Code, as subject to the conditions in Sec.  50.55a, are acceptable for 
the AMPs in the GALL Report. In a final rule issued on October 27, 2022 
(87 FR 65128), the NRC further found that Subsections IWB, IWC, IWD, 
IWE, IWF, or IWL of Section XI of the 2019 Edition of the ASME BPW 
Code, as subject to the conditions in Sec.  50.55a, are 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 (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 (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 proposed rule, the NRC evaluated whether those AMPs 
in the GALL Report and GALL-SLR Report that 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 2021 Edition. The NRC finds that the 2021 Edition of 
Section XI of the ASME BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, 
or IWL, as subject to the conditions of this proposed rule, are 
acceptable for the AMPs in the GALL Report and GALL-SLR Report with the 
exception of augmentation, as specifically noted in those reports, and 
the NRC finds that the conclusions of the GALL Report and GALL-SLR 
Report remain valid. 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 2021 Edition of the ASME BPV Code, as subject 
to the conditions in this proposed 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 2021 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.

[[Page 53398]]

    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 2021 Edition of Section XI of the ASME BPV Code is used to meet 
the requirements of Sec.  54.21(a)(3). The NRC evaluated the changes in 
the 2021 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'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 the 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 2021 Edition of the 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.

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). The NRC requests comment on this document with respect to the 
clarity and effectiveness of the language used.

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

    The NRC has determined under the National Environmental Policy Act 
of 1969, as amended, and the Commission's regulations in subpart A of 
10 CFR part 51, that this rule, if adopted, would not be a major 
Federal action significantly affecting the quality of the human 
environment and, therefore, an environmental impact statement is not 
required.
    This proposed rule is in accordance with the NRC's policy to 
incorporate by reference in Sec.  50.55a new editions of the ASME BPV 
and OM Codes to provide updated rules for construction 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 proposed 
rule 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. This proposed 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 effect on the quality of the human environment 
from this action. Public stakeholders should note, however, that 
comments on any aspect of this environmental assessment may be 
submitted to the NRC as indicated under the ADDRESSES caption.

XII. Paperwork Reduction Act Statement

    This proposed rule does not contain any new or amended collections 
of information subject to the Paperwork Reduction Act of 1995 (44 
U.S.C. 3501 et seq.). Existing collections of information were approved 
by the Office of Management and Budget (OMB), approval number 3150-
0011.

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. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113, 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. In this proposed rule, the 
NRC is continuing to use the ASME BPV and OM Codes by incorporating by 
reference the 2021 Edition of the BPV Code and the 2022 Edition of the 
OM Code. The ASME Code editions constitute voluntary consensus 
standards, in which all interested parties (including the NRC and 
licensees of nuclear power plants) participate. The NRC invites comment 
on the applicability and use of other standards.

XIV. Public Meeting

    The NRC will conduct a public meeting on the proposed rule for the 
purpose of describing the updates to the Code editions. The NRC staff 
will be available to answer questions from the public regarding this 
proposed rule.
    The NRC will publish a notice of the location, time, and agenda of 
the meeting in the Federal Register, on Regulations.gov, and on the 
NRC's public meeting website within at least 10 calendar days before 
the meeting. Stakeholders should monitor the NRC's public meeting 
website for information about the public meeting at: https://www.nrc.gov/public-involve/public-meetings/index.cfm.

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

    The NRC proposes to incorporate by reference two recent editions to 
the ASME Codes for nuclear power plants. 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 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 proposed rule a discussion of the 
ways that the materials the agency proposes to incorporate by reference 
are reasonably available to interested parties or how it worked to make 
those

[[Page 53399]]

materials reasonably available to interested parties. The discussion in 
this section complies with the requirement for proposed rules as set 
forth in Sec.  51.5(a)(1).
    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 that 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 \3\ Indian 
Tribes.
---------------------------------------------------------------------------

    \3\ 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 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 that the NRC proposes to incorporate by reference by 
rulemaking in order to participate in the rulemaking process.
    The 2021 Edition of the ASME BPV Code and the 2022 Edition of the 
ASME OM Code may be viewed, by appointment, at the Technical Library, 
which is located at Two White Flint, 11545 Rockville Pike, Rockville, 
Maryland 20852. You may submit your request to the Technical Library 
via email at [email protected] between 8:00 a.m. and 4:00 p.m. 
eastern time, Monday through Friday, except Federal holidays. In 
addition, as described in Section XV of this document, documents 
related to this proposed rule are available online in the NRC's ADAMS 
Public Documents collection at https://www.nrc.gov/reading-rm/adams.html.
    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 $325 to $720 and the cost to purchase all documents is 
approximately $9,000.
    For the class of interested parties constituting members of the 
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 
proposed rule, despite the NRC's actions to make the materials 
available at the NRC's PDR. Accordingly, the NRC requested that ASME 
consider enhancing public access to these materials during the public 
comment period. On March 2, 2023, the ASME agreed to make the materials 
available online in a read-only electronic access format during the 
public comment period (ML23068A033). Therefore, the two editions of the 
ASME Codes for nuclear power plants that the NRC proposes to 
incorporate by reference in this rulemaking are 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 proposed 
rule. Therefore, the NRC concludes that the materials the NRC proposes 
to incorporate by reference in this proposed rule are reasonably 
available to all interested parties.

XVI. 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
------------------------------------------------------------------------
           Document                       ADAMS accession No.
------------------------------------------------------------------------
Proposed Rule Documents:
    Rulemaking: Proposed       ML23032A316.
     Rule: Regulatory
     Analysis for American
     Society of Mechanical
     Engineers 2021-2022 Code
     Editions Update, July
     2023.
    Rulemaking: Proposed       ML23032A318.
     Rule: Unofficial Redline
     Strikeout of the NRC's
     Proposed Rule: RE:
     Proposed Rule to
     Incorporate by Reference
     American Society of
     Mechanical Engineers
     Codes, July 2023.
Related Documents:
    Draft regulatory guide     ML22304A054.
     (DG), DG-1403, ``Quality
     Assurance Program
     Criteria (Design and
     Construction),'' April
     2023.
    Rulemaking: Proposed       ML23068A033.
     Rule: Email from Kathryn
     Hyam (ASME) to Louise
     Lund (NRC), Request for
     Limited Public Access of
     Code for Public Comment
     Period, March 2, 2023.
    Staff Requirements--       ML003755050.
     Affirmation Session,
     11:30 a.m., Friday,
     September 10, 1999,
     Commissioners'
     Conference Room, One
     White Flint North,
     Rockville, Maryland
     (Open to Public
     Attendance).
    Regulatory Guide 1.147,    ML21181A222.
     Revision 20, ``Inservice
     Inspection Code Case
     Acceptability, ASME
     Section XI, Division
     1,'' December 2021.
    NUREG-1801, Revision 2,    ML103490041.
     ``Generic Aging Lessons
     Learned (GALL) Report,''
     December 2010.

[[Page 53400]]

 
    NUREG-1800, Revision 2,    ML103490036.
     ``Standard Review Plan
     for Review of License
     Renewal Applications for
     Nuclear Power Plants,''
     December 2010.
    NUREG-2191, ``Generic      ML17187A031
     Aging Lessons Learned     ML17187A204.
     for Subsequent License
     Renewal (GALL-SLR)
     Report,'' July 2017.
    NUREG-1950, ``Disposition  ML11116A062.
     of Public Comments and
     Technical Bases for
     Changes in the License
     Renewal Guidance
     Documents NUREG-1801 and
     NUREG-1800,'' April 2011.
    NUREG-2192, ``Standard     ML17188A158.
     Review Plan for Review
     of Subsequent License
     Renewal Applications for
     Nuclear Power Plants,''
     July 2017.
    Final Safety Evaluation    ML20322A019.
     Enclosure for NEI 14-
     05A, Rev. 1, November
     23, 2020.
    Nuclear Energy Institute   ML20135H229.
     (NEI) 14-05A,
     ``Guidelines for the Use
     of Accreditation in Lieu
     of Commercial Grade
     Surveys for Procurement
     of Laboratory
     Calibration and Test
     Services,'' Revision 1,
     May 2020.
ASME Codes, Standards, and
 Code Cases:
    ASME BPV Code, Section     https://go.asme.org/NRC-ASME.
     III, Division 1: 2021
     Edition.
    ASME BPV Code, Section     https://go.asme.org/NRC-ASME.
     XI, Division 1: 2021
     Edition.
    ASME OM Code, Division 1:  https://go.asme.org/NRC-ASME.
     2022 Edition.
------------------------------------------------------------------------

    Throughout the development of this rulemaking, the NRC may post 
documents related to this proposed rule, including public comments, on 
the Federal rulemaking website at https://www.regulations.gov under 
Docket ID NRC-2018-0289. The Federal rulemaking website allows members 
of the public to receive alerts when changes or additions occur in a 
docket folder. To subscribe take the following steps: (1) navigate to 
the docket folder (NRC-2018-0289); (2) click the ``Subscribe'' link; 
and (3) enter an email address and click on the ``Subscribe'' button.

List of Subjects in 10 CFR Part 50

    Administrative practice and procedure, Antitrust, Backfitting, 
Classified information, Criminal penalties, Education, Emergency 
planning, 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. 553, the NRC proposes to adopt 
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, Pub. L. 96-295, 94 Stat. 783.

0
2. In Sec.  50.55a:
0
a. In paragraph (a)(1)(i)(E)(19), remove the word ``and'';
0
b. Revise paragraph (a)(1)(i)(E)(20);
0
c. Add paragraph (a)(1)(i)(E)(21);
0
d. In paragraph (a)(1)(ii)(C)(55), remove the word ``and'';
0
e. Revise paragraph (a)(1)(ii)(C)(56);
0
f. Add paragraph (a)(1)(ii)(C)(57);
0
g. Revise paragraphs (a)(1)(iii)(D) and (a)(1)(iv)(C);
0
h. Revise paragraph (b)(1)(iv);
0
i. Revise paragraphs (b)(1)(vi), (b)(1)(xi) introductory text, 
(b)(1)(xi)(B), and (b)(1)(xiii);
0
j. Add paragraph (b)(1)(xiv);
0
k. Revise paragraphs (b)(2) introductory text, (b)(2)(viii), and (ix);
0
l. Remove and reserve paragraph (b)(2)(xv);
0
m. Revise paragraph (b)(2)(xxxiv);
0
n. Add paragraphs (b)(2)(xliv) through (xlix);
0
o. Revise paragraph (b)(3)(ii) introductory text;
0
p. Remove and reserve paragraphs (b)(3)(iii)(B) and (C);
0
q. Revise paragraphs (b)(3)(vii) and (x);
0
r. In the last sentence of the introductory text to paragraph (d), 
remove the text ``conditions:'' and add in its place the text 
``conditions.'';
0
s. Add paragraph (g)(6)(ii)(D)(9); and
0
t. Revise paragraphs (g)(6)(ii)(F)(1) and (8).
    The revisions and additions read as follows:


Sec.  50.55a  Codes and standards.

    (a) * * *
    (1) * * *
    (i) * * *
    (E) * * *
    (20) 2019 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices); and
    (21) 2021 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices).
    (ii) * * *
    (C) * * *
    (56) 2019 Edition; and
    (57) 2021 Edition.
    (iii) * * *
    (D) ASME BPV Code Case N-770-7. ASME BPV Code Case N-770-7, 
``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: December 4, 2020), with the conditions in paragraph (g)(6)(ii)(F) 
of this section.
* * * * *
    (iv) * * *
    (C) Operation and Maintenance of Nuclear Power Plants, ``Division 
1: OM Code: Section IST'':
    (1) 2012 Edition;
    (2) 2017 Edition;
    (3) 2020 Edition; and
    (4) 2022 Edition.
* * * * *
    (b) * * *
    (1) * * *
    (iv) Section III condition: Quality Assurance. When applying 
editions and addenda later than the 1989 Edition of Section III, an 
applicant or licensee may use the requirements of NQA-1, ``Quality 
Assurance Requirements for Nuclear Facility Applications,'' that is 
both incorporated by reference in paragraph (a)(1)(v) of this section 
and specified in either NCA-4000 or NCA-

[[Page 53401]]

7000 of that Edition and Addenda of Section III, with the exceptions in 
paragraph (b)(1)(iv)(A) of this section, provided that the 
administrative, quality, and technical provisions contained in that 
Edition and Addenda of Section III are used in conjunction with the 
applicant's or licensee's appendix B to this part quality assurance 
program; and that the applicant's or licensee's Section III activities 
comply with those commitments contained in the applicant's or 
licensee's quality assurance program description. Where NQA-1 and 
Section III do not address the commitments contained in the applicant's 
or licensee's appendix B quality assurance program description, those 
licensee commitments must be applied to Section III activities.
    (A) Subpart 2.19 in NQA-1-2017, NQA-1-2019 and NQA-1-2022 is not 
approved for use
    (B) [Reserved]
* * * * *
    (vi) Section III condition: Subsection NH. The provisions in 
Subsection NH, ``Class 1 Components in Elevated Temperature Service,'' 
1995 Addenda through all editions and addenda up to and including the 
2013 Edition incorporated by reference in paragraph (a)(1) of this 
section, may only be used for the design and construction of Type 316 
stainless steel pressurizer heater sheaths where service conditions do 
not cause the components to reach temperatures exceeding 900 [deg]F. 
This condition is not applicable to the 2015 Edition and later 
editions.
* * * * *
    (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 first provision in 
paragraph (b)(1)(xi)(A) of this section. When applying the 2015 through 
2021 Editions of Section III, Mandatory Appendix XXVI, ``Rules for 
Construction of Class 3 Buried Polyethylene Pressure Piping,'' 
applicants or licensees must meet the second provision in paragraph 
(b)(1)(xi)(B) of this section. When applying the 2017 Edition of 
Section III, Mandatory Appendix XXVI, ``Rules for Construction of Class 
3 Buried Polyethylene Pressure Piping,'' applicants or licensees must 
meet the third provision in paragraph (b)(1)(xi)(C) of this section.
* * * * *
    (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 of the 2015 
through 2021 Editions of BPV Code Section III, 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.
* * * * *
    (xiii) Section III Condition: Preservice Inspection of Steam 
Generator Tubes. Applicants or licensees applying the provisions of NB-
5283 and NB-5360 in the 2019 Edition of Section III through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(i) of 
this section, must apply paragraphs (b)(1)(xiii)(A) and (B) of this 
section.
    (A) Preservice Inspection of Steam Generator Tubes: First 
provision. When applying the provisions of NB-5283 in the 2019 Edition 
of Section III through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(i) of this section, a full-length 
preservice examination of 100 percent of the steam generator tubing in 
each newly installed steam generator must be performed prior to plant 
startup.
    (B) Preservice Inspection of Steam Generator Tubes: Second 
provision. When applying the provisions of NB-5360 in the 2019 Edition 
of Section III through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(i) of this section, flaws revealed during 
preservice examination of steam generator tubing performed in 
accordance with paragraph (b)(1)(xiii)(A) of this section must be 
evaluated using the criteria in the design specifications.
    (xiv) Section III condition: Repairs to Stamped Components. 
Applicants or licensees applying the provisions of NCA-8151, NCA-8500 
and Nonmandatory Appendix NN in the 2021 Edition of Section III, are 
required to meet all of the requirements in Nonmandatory Appendix NN.
    (2) Conditions on ASME BPV Code, Section XI. As used in this 
section, references to Section XI refer to Section XI, Division 1, in 
the editions and addenda of the ASME BPV Code incorporated by reference 
in paragraph (a)(1)(ii) of this section, subject to the following 
conditions:
* * * * *
    (viii) Section XI condition: Concrete containment examinations. 
Applicants or licensees applying Subsection IWL, 2001 Edition through 
the 2004 Edition, up to and including the 2006 Addenda, must apply 
paragraphs (b)(2)(viii)(E) through (G) of this section. Applicants or 
licensees applying Subsection IWL, 2007 Edition up to and including the 
2008 Addenda must apply paragraph (b)(2)(viii)(E) of this section. 
Applicants or licensees applying Subsection IWL, 2007 Edition with the 
2009 Addenda through the 2019 Edition, must apply paragraphs 
(b)(2)(viii)(H) and (I) of this section.
    (ix) Section XI condition: Metal containment examinations. 
Applicants or licensees applying Subsection IWE, 2001 Edition up to and 
including the 2003 Addenda, must satisfy the requirements of paragraphs 
(b)(2)(ix)(A) and (B), (F) through (I), and (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), (F) through (H), and (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 (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), (J), and (K) of this section. Applicants or 
licensees applying Subsection IWE, 2017 Edition, through the 2019 
Edition, must satisfy the requirements of paragraphs (b)(2)(ix)(A)(2) 
and (b)(2)(ix)(B) and (J) of this section. Applicants or licensees 
applying Subsection IWE, 2021 Edition, through the latest edition and 
addenda incorporated by reference in paragraph (a)(1)(ii) of this 
section must satisfy the requirements of paragraphs (b)(2)(ix)(B) and 
(J) of this section.
* * * * *
    (xxxiv) Section XI condition: Nonmandatory Appendix U.
    (A) When using Nonmandatory Appendix U of the ASME BPV Code, 
Section XI, 2013 Edition through the 2019 Edition, the following 
conditions apply:
    (1) The repair or replacement activities temporarily deferred under 
the provisions of Nonmandatory Appendix U must be performed during the 
next schedule refueling outage.
    (2) In lieu of the appendix referenced in paragraph U-S1-4.2.1(c) 
of Appendix U of the 2013 and the 2015 Editions, the mandatory appendix 
of the latest NRC approved version of the ASME BPV Code Case N-513 in 
NRC Regulatory Guide 1.147 must be used.

[[Page 53402]]

    (B) Use of Nonmandatory Appendix U, Supplement U-S1 of the ASME BPV 
Code, Section XI, 2021 Edition is prohibited.
* * * * *
    (xliv) Section XI condition: Nonmandatory Appendix Y. When using 
Nonmandatory Appendix Y of the ASME BPV Code, Section XI, 2021 Edition, 
the following conditions apply:
    (A) Use of Nonmandatory Appendix Y, Article Y-2200 is prohibited.
    (B) Use of Nonmandatory Appendix Y, Subarticle Y-2440 is 
prohibited.
    (C) Use of Nonmandatory Appendix Y, Article Y-3200 is prohibited.
    (xlv) Section XI condition: Pressure Testing of Containment 
Penetration Piping After Repair/Replacement Activities. Applicants or 
licensees applying the provision of IWA-4540(a) and (e) of the 2021 
Edition of the ASME Code, Section XI, are required to perform a VT-2 
examination of the area affected by the repair/replacement activity 
during the Type C test in appendix J to this part.
    (xlvi) Section XI condition: Contracted Repair/Replacement 
Organization Fabricating Items Offsite of the Owner's Facility. When 
applicants or licensees apply the provision of IWA-4143 in the 2021 
Edition of Section XI of the ASME Code, a contracted Repair/Replacement 
Organization fabricating ASME Code, Section III parts, appurtenances, 
piping subassemblies, and supports offsite of the Owner's facility 
(e.g., vendor facility) without an ASME Certificate of Authorization 
and without applying an ASME Stamp/Certification Mark is prohibited.
    (xlvii) Section XI condition: Weld Overlay Design Crack Growth 
Analysis. Under Subparagraph Q-3000(a) stress corrosion crack growth 
analysis is required within the weld overlay material.
    (xlviii) Section XI condition: Analytical Evaluations of 
Degradation. Applicants or licensees using the 2021 Edition of Section 
XI must submit analytical evaluations performed as required by IWB-
3132.3 and IWC-3132.3 to the Nuclear Regulatory Commission.
    (xlix) Section XI condition: Analytical Evaluations of Flaws in 
Cladding. The use of IWB-3600(b)(1) in the 2021 Edition of ASME BPV 
Code, Section XI (Division 1) is prohibited for the inlay and onlay 
that are subject to the augmented inspection requirements in paragraph 
(g)(6)(ii)(F) of this section.
    (3) * * *
    (ii) OM condition: Motor-Operated Valve (MOV) testing. Licensees 
must comply with the provisions for testing MOVs in ASME OM Code, ISTC 
4.2, 1995 Edition with the 1996 and 1997 Addenda, or ISTC-3500, 1998 
Edition through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(iv) of this section, and must establish a 
program to ensure that MOVs continue to be capable of performing their 
design basis safety functions. Licensees implementing ASME OM Code, 
Mandatory Appendix III, ``Preservice and Inservice Testing of Active 
Electric Motor-Operated Valve Assemblies in Water-Cooled Reactor 
Nuclear Power Plants,'' of the 2009 Edition, through the latest edition 
and addenda of the ASME OM Code incorporated by reference in paragraph 
(a)(1)(iv) of this section shall comply with the following conditions 
(with the exception of conditions in paragraphs (A), (B), and (C) when 
implementing the 2022 Edition of the ASME OM Code):
* * * * *
    (vii) OM condition: Snubber visual examination interval extension. 
When implementing Subsection ISTD, paragraph ISTD-4253, and Note 7 of 
Table ISTD-4252-1, in the 2022 Edition of the ASME OM Code, 
incorporated by reference in paragraph (a)(1)(iv) of this section, to 
extend snubber visual examination beyond 2 refueling cycles (48 
months), the licensee is prohibited from applying OM Code Case OMN-15, 
Revision 2, to extend the operational readiness testing interval of 
snubbers.
* * * * *
    (x) OM condition: Class 1 Pressure Relief Valve Sample Expansion. 
When implementing paragraph I-1320(c)(1) in Appendix I, ``Inservice 
Testing of Pressure Relief Devices in Water-Cooled Reactor Nuclear 
Power Plants,'' of the editions and addenda of the ASME OM Code, 
incorporated by reference in paragraph (a)(1)(iv) of this section, the 
requirement for sample expansion of Class 1 Pressure Relief Valves 
shall be implemented such that for each valve tested for which the as-
found set-pressure (first test actuation) exceeds the plus/minus 
tolerance limit of the Owner-established design set-pressure acceptance 
criteria of paragraph I-1310(e), or 3 percent of valve 
nameplate set-pressure if the Owner has not established design set-
pressure acceptance criteria, two additional valves shall be tested 
from the same valve group.
* * * * *
    (g) * * *
    (6) * * *
    (ii) * * *
    (D) * * *
    (9) Volumetric Qualifications. Volumetric examinations of Table 1 
of ASME Code Case N-729-6 may be qualified in accordance with Section 
XI, Division 1, Mandatory Appendix VIII, Supplement 15, in the 2021 
Edition or later Editions, in lieu of subparagraphs (a) through (j) of 
2500 of ASME Code Case N-729-6.
* * * * *
    (F) * * *
    (1) Implementation. Holders of operating licenses or combined 
licenses for pressurized-water reactors as of or after September 7, 
2023, shall implement the requirements of ASME BPV Code Case N-770-7 
instead of ASME BPV Code Case N-770-5, subject to the conditions 
specified in paragraphs (g)(6)(ii)(F)(2) through (16) of this section, 
by no later than one year after September 7, 2023. All NRC authorized 
alternatives from previous versions of paragraph (g)(6)(ii)(F) of this 
section remain applicable.
* * * * *
    (8) Optimized weld overlay examination. Following initial inservice 
volumetric inspection for Inspection Items C-2 and F-2 of Table 1 of 
ASME Code Case N-770-7, for weld overlay examination volumes that show 
no indication of crack growth or new cracking, in lieu of sample 
population, 100 percent of these optimized weld overlayed welds shall 
be added to the ISI program in accordance with -2410 of ASME Code Case 
N-770-7 and shall be examined once each inspection interval.
* * * * *

    Dated: July 18, 2023.

    For the Nuclear Regulatory Commission.
Andrea D. Veil,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2023-16686 Filed 8-7-23; 8:45 am]
BILLING CODE 7590-01-P