Pressurized Thermal Shock; Reports on the Technical Basis and Public Workshop, 46522-46525 [E6-13236]
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46522
Federal Register / Vol. 71, No. 156 / Monday, August 14, 2006 / Notices
jlentini on PROD1PC65 with NOTICES
Date & Time: August 14, 2006, 8 a.m.–
7 p.m., August 15–16, 2006, 8 a.m.–5
p.m., August 17, 2006, 8 a.m.–3:00 p.m.
Place: Monterey Bay Aquarium
Research Institute (MBARI), in Moss
Landing, CA.
Type of Meeting: Open.
Contact Person: Dr. Alexandria Isern,
Program Director, Division of Ocean
Science, National Science Foundation,
4201 Wilson Blvd., Arlington, VA
22230.
Purpose of Meeting: To review the
scope and system level implementation
plans for the Ocean Observatories
Initiative (OOI) including management
plans and budgeting, and determine
whether all major risks with his project
have been identified and whether
appropriate initial system development
specifications has been established for
each sub-element of the OOI.
Reason for Late Notice:
Administrative Oversight.
Agenda: To review elements of the
initial Ocean Observatories Initiative
(OOI) Project Execution Plan (PEP) and
the project’s plans for further
development of the OOI to the
Preliminary Design phrase of project
maturity.
August 14, 2006—Plenary session
designed to orient the review panel and
NSF staff to progress on high level
activities related to OOI science,
engineering, and management by the
project staff and associated experts.
Review of management issues. At the
end of the day the panel will present
concerns to the project team to be
addressed at the start of day 2. After this
presentation, the breakout groups will
meet with Project leads for Level-2
Work Breakdown Structure (WBS)
elements to coordinate for breakout
sessions on day 2.
August 15, 2006—Break out sessions
will review specific OOI WBS elements.
At the end of the day the panel will
present concerns to the project team to
be addressed at the start of day 3. There
will be a site tour of facilities and
activities related to OOI on the second
day.
August 16, 2006—Breakout sessions
continue in the morning. Meet plenary
at the end of the day to address any
lingering questions of the Panel.
August 17, 2006—Review Panel drafts
Critical Design review (CDR) report and
presents a summary of the report
findings to the project team at a closeout
session.
Dated: August 8, 2006.
Susanne Bolton,
Committee Management Officer.
[FR Doc. 05–6883 Filed 8–11–06; 8:45 am]
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NUCLEAR REGULATORY
COMMISSION
Pressurized Thermal Shock; Reports
on the Technical Basis and Public
Workshop
Nuclear Regulatory
Commission.
ACTION: Notice of availability; notice of
workshop.
AGENCY:
SUMMARY: The Nuclear Regulatory
Commission (NRC) is making available
reports documenting the technical basis
for a proposed revision of the NRC’s
pressurized thermal shock regulations.
The NRC will also be conducting a twoday public workshop on this topic. The
workshop is open to the public and all
interested parties may attend.
DATES: The NRC is not soliciting
comments at this time; however, NRC
will request formal public comments
when a notice of proposed rulemaking
is published in the Federal Register.
The public workshop will be:
September 7, 2006, from 8:30 a.m.–12
p.m., Room T10–A1, and from 1 p.m.–
4:45 p.m., Room T9–A1; September 8,
2006, from 9:30 a.m.–3:45 p.m., Room
T9–A1. If you plan to attend the
workshop you are encouraged to
preregister in order to facilitate security
check-in on the day of the meeting.
ADDRESSES: Documents related to the
proposed technical basis can be
accessed electronically at https://
www.nrc.gov/reading-rm/adams/webbased.html. From this site, you can
access ADAMS, which provides text
and image files of the NRC’s publicly
available documents. If you do not have
access to ADAMS or if you experience
problems accessing documents in
ADAMS, contact the NRC’s Public
Document Room (PDR) reference staff
by telephone at 1–800–397–4209 or
301–415–4737, or by e-mail to
PDR@nrc.gov. These documents may
also be viewed on public computers
located in the NRC’s Public Document
Room, Room O1–F21, One White Flint
North, 11555 Rockville Pike, Rockville,
Maryland, 20852. The PDR reproduction
contractor will provide hard copies of
the documents for a fee.
FOR FURTHER INFORMATION CONTACT: Dr.
Mark T. Kirk, Office of Nuclear
Regulatory Research, Component
Integrity Branch, U.S. Nuclear
Regulatory Commission, Washington,
DC 20555–0001, telephone (301) 415–
6015, facsimile 301–415–5074; e-mail
MTK@nrc.gov.
During the
operation of a nuclear power plant, the
walls of the reactor pressure vessel
SUPPLEMENTARY INFORMATION:
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(RPV) are exposed to neutron radiation,
resulting in localized embrittlement of
the vessel steel and weld materials in
the core area. If an embrittled RPV had
an existing flaw of critical size and
certain postulated severe system
transients were to occur, the flaw could
very rapidly propagate through the
vessel, resulting in a through-wall crack
and challenging the integrity of the RPV.
The postulated severe transients of
concern, known as pressurized thermal
shock (PTS) events, are characterized by
a rapid cooling (i.e., thermal shock) of
the internal RPV surface in combination
with repressurization of the RPV. The
coincident occurrence of critical-size
flaws, embrittled vessel steel and weld
material, and a severe PTS transient is
a very low-probability event.
Additionally, only a few currently
operating pressurized-water reactors are
projected to closely approach the
current statutory limit on the level of
embrittlement, as set forth in Title 10,
Section 50.61, of the Code of Federal
Regulations (10 CFR 50.61), ‘‘Fracture
Toughness Requirements for Protection
Against Pressurized Thermal Shock
Events,’’ during their planned
operational life.
Advancements in our understanding
and knowledge of materials behavior,
our ability to realistically model plant
systems and operational characteristics,
and our ability to better evaluate PTS
transients to estimate loads on vessel
walls led NRC to conclude that the
earlier analysis, conducted in the course
of developing the PTS Rule in the
1980s, contained significant
conservatism. Consistent with the NRC’s
Strategic Plan and the strategy to use
realistically conservative, safety-focused
research programs to resolve safetyrelated issues, the NRC’s Office of
Nuclear Regulatory Research (RES)
undertook a project in 1999 to develop
a technical basis to support a riskinformed revision of 10 CFR 50.61. Two
central features of the research approach
include a focus on the use of realistic
input values and models and an explicit
treatment of uncertainties (using
currently available uncertainty analysis
tools and techniques). This approach
improved significantly upon that
employed to establish the embrittlement
limits in 10 CFR 50.61, which originally
included intentional and unquantified
conservatism in many aspects of the
analysis and treated uncertainties
implicitly by incorporating them into
the models.
In early 2005, RES completed a series
of reports that describe in detail the
results of the project initiated in 1999.
The information in these reports
demonstrates that even through the
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Federal Register / Vol. 71, No. 156 / Monday, August 14, 2006 / Notices
period of license extension, the
likelihood of vessel failure attributable
to PTS is extremely low (≈10¥8/year).
These results provide evidence that the
statutory embrittlement limit
established in 10 CFR 50.61 can be
modified significantly to reduce
unnecessary conservatism without
affecting safety. This is possible because
the operating reactor fleet has little
probability of exceeding the limits on
the frequency of reactor vessel failure,
as they relate to NRC guidelines on core
damage frequency and large early
release frequency during either the
currently licensed lifetime or the period
of license extension.
In early 2005, the RES reports were
discussed with the NRC’s Advisory
Committee on Reactor Safeguards
(ACRS) during a series of public
meetings. Following these meetings, the
ACRS sent letters to the NRC expressing
the view that RES had developed a
sound technical basis for a riskinformed revision of 10 CFR 50.61.
More recently (June—October 2005)
staff from the NRC’s Office of Nuclear
Reactor Regulation (NRR) reviewed this
technical basis and found it acceptable
to begin the rulemaking process
contingent upon the following three
prerequisites:
(1) Commission approval of the
rulemaking plan, and dedication of
resources
(2) Successful resolution of
outstanding technical issues identified
in the existing technical basis
(3) Making the technical basis
documents available to the public
Topical area
ADAMS ML#
Previous Results ..................................................
ML030090626
Current Results Summary ....................................
ML061580318
Probabilistic Risk Assessment & Human Factors
Analysis.
ML992710066
ML061580379
ML042880452
ML042880454
ML042880473
ML042880482
ML042880476
Thermal Hydraulics ..............................................
ML050390012
ML043570429
ML043570405
ML043570394
ML061100488
ML043570385
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ML061170401
Probabilistic Fracture Mechanics .........................
ML042880480
ML061580343
ML051790410
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This notice addresses prerequisite
number 3.
Public Availability of Reports
The following table provides the
document titles and Agencywide
Documents Access and Management
System (ADAMS) accession numbers for
all of the reports that, collectively,
comprise the proposed technical basis
for risk-informed revision of 10 CFR
50.61. The NRC staff recommends that
persons interested in obtaining an
overview of the technical basis and the
recommended revisions to 10 CFR 50.61
focus their attention first on ADAMS
Accession #ML061580318. Interested
persons can find more detailed
information in the other supporting
documents.
Author & title
Kirk, M.T., ‘‘Technical Basis for Revision of the Pressurized Thermal
Shock (PTS) Screening Criteria in the PTS Rule (10 CFR 50.61),’’ December 2002.
Kirk, M.T., et al., ‘‘Technical Basis for Revision of the Pressurized Thermal Shock (PTS) Screening Limit in the PTS Rule (10 CFR 50.61):
Summary Report,’’ NUREG–1806, Vol. 1.
Sui, N., ‘‘Uncertainty Analysis and Pressurized Thermal Shock: An Opinion,’’ September 3, 1999.
Whitehead, D.W., and A.M. Kolaczkowski, ‘‘PRA Procedures and Uncertainty for PTS Analysis,’’ NUREG/CR–6859.
Kolaczkowski, A.M., et al., ‘‘Oconee Pressurized Thermal Shock (PTS)
Probabilistic Risk Assessment (PRA),’’ September 28, 2004.
Whitehead, D.W., et al., ‘‘Beaver Valley Pressurized Thermal Shock
(PTS) Probabilistic Risk Assessment (PRA),’’ September 28, 2004.
Whitehead, D.W., et al., ‘‘Palisades Pressurized Thermal Shock (PTS)
Probabilistic Risk Assessment (PRA),’’ October 6, 2004.
Whitehead, D.W., et al., ‘‘Generalization of Plant-Specific Pressurized
Thermal Shock (PTS) Risk Results to Additional Plants,’’ December
14, 2004.
Kolaczkowski, A.M. et al., ‘‘Estimates of External Events Contribution to
Pressurized Thermal Shock (PTS) Risk,’’ October 1, 2004.
Bessette, D.E., ‘‘Thermal-Hydraulic Evaluation of Pressurized Thermal
Shock,’’ NUREG–1809.
Reyes, J.N., et al., ‘‘Scaling Analysis for the OSU APEX–CE Integral
System Test Facility,’’ NUREG/CR–6731.
Reyes, J.N., et al., ‘‘Final Report for the OSU APEX–CE Integral System
Test Facility Test Results,’’ NUREG/CR–6856.
Fletcher, C.D., D.A. Prelewicz, and W.C. Arcieri, ‘‘RELAP5/MOD3.2.2
Gamma Assessment for Pressurized Thermal Shock Applications,’’
NUREG/CR–6857.
Chang, Y.H.J., A. Mosleh, and K. Almenas, ‘‘Thermal-Hydraulic Uncertainty Analysis in Pressurized Thermal Shock Risk Assessment: Methodology and Implementation on Oconee-1, Beaver Valley, and Palisades Nuclear Power Plants,’’ NUREG/CR–6899.
Arcieri, W.C., R.M. Beaton, C.D. Fletcher, and D.E. Bessette, ‘‘RELAP5
Thermal-Hydraulic Analysis To Support PTS Evaluations for the
Oconee-1, Beaver Valley-1, and Palisades Nuclear Power Plants,’’
NUREG/CR–6858.
Arcieri, W.C., C.D. Fletcher, and D.E. Bessette, ‘‘RELAP5/MOD3.2.2
Gamma Results for the Palisades 1D Downcomer Sensitivity Study,’’
August 31, 2004.
Junge, M., ‘‘PTS Consistency Effort,’’ October 6, 2004.
Kirk, M.T., et al., ‘‘Probabilistic Fracture Mechanics: Models, Parameters,
and Uncertainty Treatment Used in FAVOR Version 04.1,’’ NUREG–
1807.
Simonen, F.A., S.R. Doctor, G.J. Schuster, and P.G. Heasler, ‘‘A Generalized Procedure for Generating Flaw-Related Inputs for the FAVOR
Code,’’ NUREG/CR–6817, Rev. 1.
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Topical area
ADAMS ML#
ML061580369
ML061580375
ML061580358
ML042960391
ML061580349
Public Workshop
The NRC will conduct a public
workshop on September 7–8, 2006, at
NRC Headquarters, 11545 Rockville
Pike, Rockville, Maryland. The purpose
of this workshop is to inform the public
of the reports detailed in the preceding
Author & title
Williams, P.T., T.L. Dickson, and S. Yin, ‘‘Fracture Analysis of Vessels—
Oak Ridge, FAVOR v04.1: Computer Code: Theory and Implementation of Algorithms, Methods, and Correlations,’’ NUREG/CR–6854.
Dickson, T.L., P.T. Williams, and S. Yin, ‘‘Fracture Analysis of Vessels—
Oak Ridge, FAVOR v04.1, Computer Code: User’s Guide,’’ NUREG/
CR–6855.
Malik, S.N.M., ‘‘FAVOR Code Versions 2.4 and 3.1: Verification and Validation Summary Report,’’ NUREG–1795.
Dickson, T.L., and S. Yin, ‘‘Electronic Archival of the Results of Pressurized Thermal Shock Analyses for Beaver Valley, Oconee, and Palisades Reactor Pressure Vessels Generated with the 04.1 Version of
FAVOR,’’ October 15, 2004.
Kirk, M.T., et al., ‘‘Sensitivity Studies of the Probabilistic Fracture Mechanics Model Used in FAVOR,’’ NUREG–1808.
section of this notice. A preliminary
agenda for the workshop follows. If you
plan to attend this meeting you are
urged to contact Dr. Mark Kirk via email to MTK@nrc.gov at least 3 business
days before the meeting date so that
your name can be included on the list
of attendees and so you can be advised
of any revisions to the agenda. You are
strongly encouraged to communicate via
e-mail, as this will facilitate the most
efficient response to your inquiry.
Preliminary Agenda
THURSDAY, SEPTEMBER 7, 2006
[8:30 a.m.–12 p.m., Room T10–A1; 1 p.m.–4:45 p.m., Room T9–A1]
Start time
Stop time
Duration [min]
Topic
Presenter/moderator
8:30 .................
9 .....................
30 ...................
9 ......................
9:30 .................
9:45 .................
9:30 ................
9:45 ................
10:15 ..............
30 ...................
15 ...................
30 ...................
10:15 ...............
10:30 ...............
11 ....................
11:30 ...............
12 ....................
1 ......................
10:30 ..............
11 ...................
11:30 ..............
12 ...................
1 .....................
1:30 ................
30
30
30
30
60
30
...................
...................
...................
...................
...................
...................
1:30 .................
2 ......................
3:30 .................
3:45 .................
2 .....................
3:30 ................
3:45 ................
4:45 ................
30
90
15
60
...................
...................
...................
...................
Background of PTS Project (Overview, Objectives, Reviews
Performed to Date).
Status and Plan for Rulemaking ..............................................
Overview of Reports ................................................................
Questions from Public Regarding Reports and Regulatory
Process.
Break ........................................................................................
Modeling Approach: Overview .................................................
Modeling Approach: Risk Assessment and Human Factors ...
Modeling Approach: Thermal-Hydraulics .................................
Lunch ........................................................................................
Modeling Approach: Fracture Mechanics and Material Embrittlement.
Questions from the Public Regarding Modeling Approach .....
Summary of Results from Baseline Analysis of Three Plants
Break ........................................................................................
Questions from Public Regarding Baseline Analysis ..............
Kirk
Mencinsky
Kirk
Hardies
Kirk
Kolaczkowski
Bessette
Kirk
Hardies
Kirk
Hardies
FRIDAY, SEPTEMBER 8, 2006
[9:30 a.m.–3:45 p.m., Room T9–A1]
Stop time
Duration [min]
Topic
9:30 .................
10:30 ..............
60 ...................
10:30 ...............
11 ....................
11:30 ...............
11 ...................
11:30 ..............
11:45 ..............
30 ...................
30 ...................
15 ...................
11:45 ...............
1 ......................
1 .....................
1:30 ................
75 ...................
30 ...................
1:30 .................
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Start time
2 .....................
30 ...................
2 ......................
3 ......................
3:15 .................
3 .....................
3:15 ................
3:45 ................
60 ...................
15 ...................
30 ...................
Summary of Study Generalizing the Results to All Domestic
PWRs.
Questions from the Public Regarding Generalization .............
Proposed Allowable Through-Wall Cracking Frequency Limit
Questions from the Public Regarding Through-Wall Cracking
Frequency Limit.
Lunch ........................................................................................
Proposed Material Embrittlement-Based Reference Temperature Limits for Use in a Revised Version of 10 CFR 50.61.
Questions from Public Regarding Reference Temperature
Limits.
General Questions from Public ................................................
Break ........................................................................................
Summary ..................................................................................
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Hardies
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Federal Register / Vol. 71, No. 156 / Monday, August 14, 2006 / Notices
Dated at Rockville, Maryland, this 4th day
of August, 2006.
For the U.S. Nuclear Regulatory
Commission,
James T. Wiggins,
Deputy Director, Office of Nuclear Regulatory
Research.
[FR Doc. E6–13236 Filed 8–11–06; 8:45 am]
BILLING CODE 7590–01–P
OFFICE OF MANAGEMENT AND
BUDGET
Executive Office of the President;
Acquisition Advisory Panel;
Notification of Upcoming Meetings of
the Acquisition Advisory Panel
Office of Management and
Budget, Executive Office of the
President.
ACTION: Notice of Federal Advisory
Committee Meetings.
jlentini on PROD1PC65 with NOTICES
AGENCY:
SUMMARY: The Office of Management
and Budget announces one meeting of
the Acquisition Advisory Panel (AAP or
‘‘Panel’’) established in accordance with
the Services Acquisition Reform Act of
2003.
DATES: There is one conditional meeting
announced in this Federal Register
Notice. A Public meeting of the Panel
will be held on August 29, 2006 if the
Panel does not complete its work at the
previously published public meeting on
August 10, 2006. If held, the meeting
will begin at 9 a.m. Eastern Time and
end no later than 5 p.m. The public is
urged to call (202) 208–7279 after 5 p.m.
the workday before this meeting for a
pre-recorded message to learn if the
meeting is cancelled. The public may
also visit the Panel’s Web site for
cancellation messages (https://
acquisition.gov/comp/aap/).
ADDRESSES: The August 29, 2006
meeting, if held, will be at the new FDIC
Building, 3501 N. Fairfax Drive,
Arlington, VA in Room A2062. This
facility is 1⁄4 block off of the orange line
Metro stop for Virginia Square. The
public is asked to pre-register one week
in advance of the meeting due to
security and/or seating limitations (see
below for information on preregistration).
FOR FURTHER INFORMATION: Members of
the public wishing further information
concerning this meeting or the Panel
itself, or to pre-register for the meeting,
should contact Ms. Laura Auletta,
Designated Federal Officer (DFO), at:
laura.auletta@gsa.gov, phone/voice mail
(202) 208–7279, or mail at: General
Services Administration, 1800 F Street,
NW., Room 4006, Washington, DC
20405.
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SUPPLEMENTARY INFORMATION:
a. Background: The purpose of the
Panel is to provide independent advice
and recommendations to the Office of
Federal Procurement Policy and
Congress pursuant to Section 1423 of
the Services Acquisition Reform Act of
2003. The Panel’s statutory charter is to
review Federal contracting laws,
regulations, and governmentwide
policies, including the use of
commercial practices, performancebased contracting, performance of
acquisition functions across agency
lines of responsibility, and
governmentwide contracts. Interested
parties are invited to attend the meeting.
Meeting—The focus of this meeting
will be discussions of and voting on
working group findings and
recommendations from selected
working groups, established at the
February 28, 2005 and May 17, 2005
public meetings of the AAP (see
https://acquisition.gov/comp/aap/
index.html for a list of working groups).
b. Posting of Draft Reports: Members
of the public are encouraged to regularly
visit the Panel’s Web site for draft
reports. Currently, the working groups
are staggering the posting of various
sections of their draft reports at https://
acquisition.gov/comp/aap/
under the link for ‘‘Working Group
Reports.’’ The most recent posting is
from the Commercial Practices Working
Group. The public is encouraged to
submit written comments on any and all
draft reports.
c. Adopted Recommendations: The
Panel has adopted recommendations
presented by the Small Business,
Interagency Contracting, PerformanceBased Acquisition, Acquisition
Workforce and Commercial Practices
Working Groups. While additional
recommendations from some of these
working groups are likely, the public is
encouraged to review and comment on
the recommendations adopted by the
Panel to date by going to https://
acquisition.gov/comp/aap/
and selecting the link for
‘‘Recommendations to Date.’’
d. Availability of Meeting Materials:
Please see the Panel’s Web site for any
available materials, including draft
agendas and minutes. Questions/issues
of particular interest to the Panel are
also available to the public on this Web
site on its front page, including
‘‘Questions for Government Buying
Agencies,’’ ‘‘Questions for Contractors
that Sell Commercial Goods or Services
to the Government,’’ ‘‘Questions for
Commercial Organizations,’’ and an
issue raised by one Panel member
regarding the rules of interpretation and
performance of contracts and liabilities
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46525
of the parties entitled ‘‘Revised
Commercial Practices Proposal for
Public Comment.’’ The Panel
encourages the public to address any of
these questions/issues in written
statements to the Panel.
e. Procedures for Providing Public
Comments: It is the policy of the Panel
to accept written public comments of
any length, and to accommodate oral
public comments whenever possible.
The Panel Staff expects that public
statements presented orally or in writing
will be focused on the Panel’s statutory
charter and working group topics, and
not be repetitive of previously
submitted oral or written statements,
and that comments will be relevant to
the issues under discussion.
Written Comments: Written comments
should be supplied to the DFO at the
address/contact information given in
this FR Notice in one of the following
formats (Adobe Acrobat, WordPerfect,
Word, or Rich Text files, in IBM–PC/
Windows 98/2000/XP format). Please
note: Because the Panel operates under
the provisions of the Federal Advisory
Committee Act, as amended, all public
presentations will be treated as public
documents and will be made available
for public inspection, up to and
including being posted on the Panel’s
Web site.
f. Meeting Accommodations:
Individuals requiring special
accommodation to access the public
meetings listed above should contact
Ms. Auletta at least five business days
prior to the meeting so that appropriate
arrangements can be made.
Laura Auletta,
Designated Federal Officer (Executive
Director), Acquisition Advisory Panel.
[FR Doc. E6–13288 Filed 8–11–06; 8:45 am]
BILLING CODE 3110–01–P
OFFICE OF THE UNITED STATES
TRADE REPRESENTATIVE
Request for Public Comment With
Respect to the Annual National Trade
Estimate Report on Foreign Trade
Barriers
Office of the United States
Trade Representative.
ACTION: Notice.
AGENCY:
SUMMARY: Pursuant to section 303 of the
Trade and Tariff Act of 1984, as
amended, USTR is required to publish
annually the National Trade Estimate
Report on Foreign Trade Barriers (NTE).
With this notice, the Trade Policy Staff
Committee (TPSC) is requesting
interested parties to assist it in
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]]>Agencies
[Federal Register Volume 71, Number 156 (Monday, August 14, 2006)]
[Notices]
[Pages 46522-46525]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-13236]
=======================================================================
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
Pressurized Thermal Shock; Reports on the Technical Basis and
Public Workshop
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of availability; notice of workshop.
-----------------------------------------------------------------------
SUMMARY: The Nuclear Regulatory Commission (NRC) is making available
reports documenting the technical basis for a proposed revision of the
NRC's pressurized thermal shock regulations. The NRC will also be
conducting a two-day public workshop on this topic. The workshop is
open to the public and all interested parties may attend.
DATES: The NRC is not soliciting comments at this time; however, NRC
will request formal public comments when a notice of proposed
rulemaking is published in the Federal Register. The public workshop
will be: September 7, 2006, from 8:30 a.m.-12 p.m., Room T10-A1, and
from 1 p.m.-4:45 p.m., Room T9-A1; September 8, 2006, from 9:30 a.m.-
3:45 p.m., Room T9-A1. If you plan to attend the workshop you are
encouraged to preregister in order to facilitate security check-in on
the day of the meeting.
ADDRESSES: Documents related to the proposed technical basis can be
accessed electronically at https://www.nrc.gov/reading-rm/adams/web-
based.html. From this site, you can access ADAMS, which provides text
and image files of the NRC's publicly available documents. If you do
not have access to ADAMS or if you experience problems accessing
documents in ADAMS, contact the NRC's Public Document Room (PDR)
reference staff by telephone at 1-800-397-4209 or 301-415-4737, or by
e-mail to PDR@nrc.gov. These documents may also be viewed on public
computers located in the NRC's Public Document Room, Room O1-F21, One
White Flint North, 11555 Rockville Pike, Rockville, Maryland, 20852.
The PDR reproduction contractor will provide hard copies of the
documents for a fee.
FOR FURTHER INFORMATION CONTACT: Dr. Mark T. Kirk, Office of Nuclear
Regulatory Research, Component Integrity Branch, U.S. Nuclear
Regulatory Commission, Washington, DC 20555-0001, telephone (301) 415-
6015, facsimile 301-415-5074; e-mail MTK@nrc.gov.
SUPPLEMENTARY INFORMATION: During the operation of a nuclear power
plant, the walls of the reactor pressure vessel (RPV) are exposed to
neutron radiation, resulting in localized embrittlement of the vessel
steel and weld materials in the core area. If an embrittled RPV had an
existing flaw of critical size and certain postulated severe system
transients were to occur, the flaw could very rapidly propagate through
the vessel, resulting in a through-wall crack and challenging the
integrity of the RPV. The postulated severe transients of concern,
known as pressurized thermal shock (PTS) events, are characterized by a
rapid cooling (i.e., thermal shock) of the internal RPV surface in
combination with repressurization of the RPV. The coincident occurrence
of critical-size flaws, embrittled vessel steel and weld material, and
a severe PTS transient is a very low-probability event. Additionally,
only a few currently operating pressurized-water reactors are projected
to closely approach the current statutory limit on the level of
embrittlement, as set forth in Title 10, Section 50.61, of the Code of
Federal Regulations (10 CFR 50.61), ``Fracture Toughness Requirements
for Protection Against Pressurized Thermal Shock Events,'' during their
planned operational life.
Advancements in our understanding and knowledge of materials
behavior, our ability to realistically model plant systems and
operational characteristics, and our ability to better evaluate PTS
transients to estimate loads on vessel walls led NRC to conclude that
the earlier analysis, conducted in the course of developing the PTS
Rule in the 1980s, contained significant conservatism. Consistent with
the NRC's Strategic Plan and the strategy to use realistically
conservative, safety-focused research programs to resolve safety-
related issues, the NRC's Office of Nuclear Regulatory Research (RES)
undertook a project in 1999 to develop a technical basis to support a
risk-informed revision of 10 CFR 50.61. Two central features of the
research approach include a focus on the use of realistic input values
and models and an explicit treatment of uncertainties (using currently
available uncertainty analysis tools and techniques). This approach
improved significantly upon that employed to establish the
embrittlement limits in 10 CFR 50.61, which originally included
intentional and unquantified conservatism in many aspects of the
analysis and treated uncertainties implicitly by incorporating them
into the models.
In early 2005, RES completed a series of reports that describe in
detail the results of the project initiated in 1999. The information in
these reports demonstrates that even through the
[[Page 46523]]
period of license extension, the likelihood of vessel failure
attributable to PTS is extremely low ([ap]10-8/year). These
results provide evidence that the statutory embrittlement limit
established in 10 CFR 50.61 can be modified significantly to reduce
unnecessary conservatism without affecting safety. This is possible
because the operating reactor fleet has little probability of exceeding
the limits on the frequency of reactor vessel failure, as they relate
to NRC guidelines on core damage frequency and large early release
frequency during either the currently licensed lifetime or the period
of license extension.
In early 2005, the RES reports were discussed with the NRC's
Advisory Committee on Reactor Safeguards (ACRS) during a series of
public meetings. Following these meetings, the ACRS sent letters to the
NRC expressing the view that RES had developed a sound technical basis
for a risk-informed revision of 10 CFR 50.61. More recently (June--
October 2005) staff from the NRC's Office of Nuclear Reactor Regulation
(NRR) reviewed this technical basis and found it acceptable to begin
the rulemaking process contingent upon the following three
prerequisites:
(1) Commission approval of the rulemaking plan, and dedication of
resources
(2) Successful resolution of outstanding technical issues
identified in the existing technical basis
(3) Making the technical basis documents available to the public
This notice addresses prerequisite number 3.
Public Availability of Reports
The following table provides the document titles and Agencywide
Documents Access and Management System (ADAMS) accession numbers for
all of the reports that, collectively, comprise the proposed technical
basis for risk-informed revision of 10 CFR 50.61. The NRC staff
recommends that persons interested in obtaining an overview of the
technical basis and the recommended revisions to 10 CFR 50.61 focus
their attention first on ADAMS Accession ML061580318.
Interested persons can find more detailed information in the other
supporting documents.
----------------------------------------------------------------------------------------------------------------
Topical area ADAMS ML Author & title
----------------------------------------------------------------------------------------------------------------
Previous Results............................. ML030090626 Kirk, M.T., ``Technical Basis for Revision of
the Pressurized Thermal Shock (PTS) Screening
Criteria in the PTS Rule (10 CFR 50.61),''
December 2002.
Current Results Summary...................... ML061580318 Kirk, M.T., et al., ``Technical Basis for
Revision of the Pressurized Thermal Shock
(PTS) Screening Limit in the PTS Rule (10 CFR
50.61): Summary Report,'' NUREG-1806, Vol. 1.
Probabilistic Risk Assessment & Human Factors ML992710066 Sui, N., ``Uncertainty Analysis and
Analysis. Pressurized Thermal Shock: An Opinion,''
September 3, 1999.
ML061580379 Whitehead, D.W., and A.M. Kolaczkowski, ``PRA
Procedures and Uncertainty for PTS
Analysis,'' NUREG/CR-6859.
ML042880452 Kolaczkowski, A.M., et al., ``Oconee
Pressurized Thermal Shock (PTS) Probabilistic
Risk Assessment (PRA),'' September 28, 2004.
ML042880454 Whitehead, D.W., et al., ``Beaver Valley
Pressurized Thermal Shock (PTS) Probabilistic
Risk Assessment (PRA),'' September 28, 2004.
ML042880473 Whitehead, D.W., et al., ``Palisades
Pressurized Thermal Shock (PTS) Probabilistic
Risk Assessment (PRA),'' October 6, 2004.
ML042880482 Whitehead, D.W., et al., ``Generalization of
Plant-Specific Pressurized Thermal Shock
(PTS) Risk Results to Additional Plants,''
December 14, 2004.
ML042880476 Kolaczkowski, A.M. et al., ``Estimates of
External Events Contribution to Pressurized
Thermal Shock (PTS) Risk,'' October 1, 2004.
Thermal Hydraulics........................... ML050390012 Bessette, D.E., ``Thermal-Hydraulic Evaluation
of Pressurized Thermal Shock,'' NUREG-1809.
ML043570429 Reyes, J.N., et al., ``Scaling Analysis for
the OSU APEX-CE Integral System Test
Facility,'' NUREG/CR-6731.
ML043570405 Reyes, J.N., et al., ``Final Report for the
OSU APEX-CE Integral System Test Facility
Test Results,'' NUREG/CR-6856.
ML043570394 Fletcher, C.D., D.A. Prelewicz, and W.C.
Arcieri, ``RELAP5/MOD3.2.2 Gamma Assessment
for Pressurized Thermal Shock Applications,''
NUREG/CR-6857.
ML061100488 Chang, Y.H.J., A. Mosleh, and K. Almenas,
``Thermal-Hydraulic Uncertainty Analysis in
Pressurized Thermal Shock Risk Assessment:
Methodology and Implementation on Oconee-1,
Beaver Valley, and Palisades Nuclear Power
Plants,'' NUREG/CR-6899.
ML043570385 Arcieri, W.C., R.M. Beaton, C.D. Fletcher, and
D.E. Bessette, ``RELAP5 Thermal-Hydraulic
Analysis To Support PTS Evaluations for the
Oconee-1, Beaver Valley-1, and Palisades
Nuclear Power Plants,'' NUREG/CR-6858.
ML061170401 Arcieri, W.C., C.D. Fletcher, and D.E.
Bessette, ``RELAP5/MOD3.2.2 Gamma Results for
the Palisades 1D Downcomer Sensitivity
Study,'' August 31, 2004.
ML042880480 Junge, M., ``PTS Consistency Effort,'' October
6, 2004.
Probabilistic Fracture Mechanics............. ML061580343 Kirk, M.T., et al., ``Probabilistic Fracture
Mechanics: Models, Parameters, and
Uncertainty Treatment Used in FAVOR Version
04.1,'' NUREG-1807.
ML051790410 Simonen, F.A., S.R. Doctor, G.J. Schuster, and
P.G. Heasler, ``A Generalized Procedure for
Generating Flaw-Related Inputs for the FAVOR
Code,'' NUREG/CR-6817, Rev. 1.
[[Page 46524]]
ML061580369 Williams, P.T., T.L. Dickson, and S. Yin,
``Fracture Analysis of Vessels--Oak Ridge,
FAVOR v04.1: Computer Code: Theory and
Implementation of Algorithms, Methods, and
Correlations,'' NUREG/CR-6854.
ML061580375 Dickson, T.L., P.T. Williams, and S. Yin,
``Fracture Analysis of Vessels--Oak Ridge,
FAVOR v04.1, Computer Code: User's Guide,''
NUREG/CR-6855.
ML061580358 Malik, S.N.M., ``FAVOR Code Versions 2.4 and
3.1: Verification and Validation Summary
Report,'' NUREG-1795.
ML042960391 Dickson, T.L., and S. Yin, ``Electronic
Archival of the Results of Pressurized
Thermal Shock Analyses for Beaver Valley,
Oconee, and Palisades Reactor Pressure
Vessels Generated with the 04.1 Version of
FAVOR,'' October 15, 2004.
ML061580349 Kirk, M.T., et al., ``Sensitivity Studies of
the Probabilistic Fracture Mechanics Model
Used in FAVOR,'' NUREG-1808.
----------------------------------------------------------------------------------------------------------------
Public Workshop
The NRC will conduct a public workshop on September 7-8, 2006, at
NRC Headquarters, 11545 Rockville Pike, Rockville, Maryland. The
purpose of this workshop is to inform the public of the reports
detailed in the preceding section of this notice. A preliminary agenda
for the workshop follows. If you plan to attend this meeting you are
urged to contact Dr. Mark Kirk via e-mail to MTK@nrc.gov at least 3
business days before the meeting date so that your name can be included
on the list of attendees and so you can be advised of any revisions to
the agenda. You are strongly encouraged to communicate via e-mail, as
this will facilitate the most efficient response to your inquiry.
Preliminary Agenda
Thursday, September 7, 2006
[8:30 a.m.-12 p.m., Room T10-A1; 1 p.m.-4:45 p.m., Room T9-A1]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Start time Stop time Duration [min] Topic Presenter/moderator
--------------------------------------------------------------------------------------------------------------------------------------------------------
8:30............................... 9..................... 30.................... Background of PTS Project Kirk
(Overview, Objectives,
Reviews Performed to
Date).
9.................................. 9:30.................. 30.................... Status and Plan for Mencinsky
Rulemaking.
9:30............................... 9:45.................. 15.................... Overview of Reports....... Kirk
9:45............................... 10:15................. 30.................... Questions from Public Hardies
Regarding Reports and
Regulatory Process.
10:15.............................. 10:30................. 30.................... Break..................... .......................................
10:30.............................. 11.................... 30.................... Modeling Approach: Kirk
Overview.
11................................. 11:30................. 30.................... Modeling Approach: Risk Kolaczkowski
Assessment and Human
Factors.
11:30.............................. 12.................... 30.................... Modeling Approach: Thermal- Bessette
Hydraulics.
12................................. 1..................... 60.................... Lunch..................... .......................................
1.................................. 1:30.................. 30.................... Modeling Approach: Kirk
Fracture Mechanics and
Material Embrittlement.
1:30............................... 2..................... 30.................... Questions from the Public Hardies
Regarding Modeling
Approach.
2.................................. 3:30.................. 90.................... Summary of Results from Kirk
Baseline Analysis of
Three Plants.
3:30............................... 3:45.................. 15.................... Break..................... .......................................
3:45............................... 4:45.................. 60.................... Questions from Public Hardies
Regarding Baseline
Analysis.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Friday, September 8, 2006
[9:30 a.m.-3:45 p.m., Room T9-A1]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Start time Stop time Duration [min] Topic Presenter/Moderator
--------------------------------------------------------------------------------------------------------------------------------------------------------
9:30............................... 10:30................. 60.................... Summary of Study Kirk
Generalizing the Results
to All Domestic PWRs.
10:30.............................. 11.................... 30.................... Questions from the Public Hardies
Regarding Generalization.
11................................. 11:30................. 30.................... Proposed Allowable Through- Siu
Wall Cracking Frequency
Limit.
11:30.............................. 11:45................. 15.................... Questions from the Public Hardies
Regarding Through-Wall
Cracking Frequency Limit.
11:45.............................. 1..................... 75.................... Lunch..................... .......................................
1.................................. 1:30.................. 30.................... Proposed Material Kirk
Embrittlement-Based
Reference Temperature
Limits for Use in a
Revised Version of 10 CFR
50.61.
1:30............................... 2..................... 30.................... Questions from Public Hardies
Regarding Reference
Temperature Limits.
2.................................. 3..................... 60.................... General Questions from Hardies
Public.
3.................................. 3:15.................. 15.................... Break..................... .......................................
3:15............................... 3:45.................. 30.................... Summary................... Hardies
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 46525]]
Dated at Rockville, Maryland, this 4th day of August, 2006.
For the U.S. Nuclear Regulatory Commission,
James T. Wiggins,
Deputy Director, Office of Nuclear Regulatory Research.
[FR Doc. E6-13236 Filed 8-11-06; 8:45 am]
BILLING CODE 7590-01-P
