[Federal Register Volume 87, Number 78 (Friday, April 22, 2022)]
[Notices]
[Pages 24205-24207]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-08617]
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NUCLEAR REGULATORY COMMISSION
[NRC-2022-0085]
Level 3 Probabilistic Risk Assessment Project Documentation
(Volume 3x)
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft report; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment a draft report on the Level 3 Probabilistic Risk
Assessment (PRA) project; specifically, ``Volume 3x: Overview of
Reactor, At-Power, Level 1, 2, and 3 PRAs for Internal Events and
Internal Floods.''
DATES: Submit comments by June 21, 2022. Comments received after this
date
[[Page 24206]]
will be considered if it is practical to do so, but the Commission 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;
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-2022-0085. Address
questions about Docket IDs in Regulations.gov to Stacy Schumann;
telephone: 301-415-0624; email: [email protected]. For technical
questions, contact the individual listed in the For Further Information
Contact section of this document.
Mail comments to: Office of Administration, Mail Stop:
TWFN-7-A60M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001, ATTN: Program Management, Announcements and Editing Staff.
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: Alan Kuritzky, Office of Nuclear
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, telephone: 301-415-1552, email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2022-0085 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-2022-0085.
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, 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
8:00 a.m. and 4:00 p.m. (ET), 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-2022-0085 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. Discussion
As directed in SRM-SECY-11-0089, ``Options for Proceeding with
Future Level 3 Probabilistic Risk Assessment (PRA) Activities,'' the
staff is conducting a full-scope multi-unit site Level 3 PRA (Level 3
PRA project) that addresses all internal and external hazards; all
plant operating modes; and all reactor units, spent fuel pools, and dry
cask storage. The reference site for this study contains two four-loop
Westinghouse PWRs with large dry containments. The objectives of the
Level 3 PRA project are to (1) develop a Level 3 PRA, generally based
on current state-of-practice methods, tools, and data, that (a)
reflects technical advances since the last NRC-sponsored Level 3 PRAs
(NUREG-1150), which were completed over 30 years ago, and (b) addresses
scope considerations that were not previously considered (e.g., low
power and shutdown risk, multi-unit risk, other radiological sources);
(2) extract new insights to enhance regulatory decision making and to
help focus limited NRC resources on issues most directly related to the
agency's mission to protect public health and safety; (3) enhance PRA
staff capability and expertise and improve documentation practices to
make PRA information more accessible, retrievable, and understandable;
and (4) demonstrate technical feasibility and evaluate the realistic
cost of developing new Level 3 PRAs.
The work performed under this project is being documented as a
multi-volume report. This first batch of Level 3 PRA project reports
provides a high-level discussion of the overall project technical
approach (Volume 2) and describes the analyses and results for the
reactor, at-power, Level 1, 2, and 3 PRAs for internal events and
internal floods (Volume 3). Each set of Level 3 PRA project reports
covering the Level 1, 2, and 3 PRAs for a specific site radiological
source, plant operating state, and hazard group (or groups) is
accompanied by an overview report. The overview reports summarize the
results and insights from all three PRA levels.
The Level 3 PRA project analyses reflect the reference plant as it
was designed and operated as of 2012. To provide results and insights
better aligned with the current design and operation of the reference
plant, the overview reports also provide a reevaluation of the plant
risk based on a set of new plant equipment and PRA model assumptions
and compare the results of the reevaluation to the original study
results. This reevaluation reflects the current reactor coolant pump
shutdown seal design at the reference plant, as well as the potential
impact of FLEX strategies, both of which reduce the risk to the public.
The results of the original Level 3 PRA project analyses and the
reevaluation both show that, when considering internal events and
floods, the combination of this plant design and site location has
substantial margin to the quantitative health objectives related to the
NRC's safety goal policy. Even though these margins can vary for other
plants due to variations in their design and siting, the estimates
derived for the reference plant, when adjusted for siting and design
variations, would provide useful qualitative risk insights for other
U.S. operating plants.
III. Availability of Documents
The documents identified in the following table are available to
[[Page 24207]]
interested persons through ADAMS, as indicated.
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ADAMS
Document description Accession No.
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SRM-SECY-11-0089, ``Options for Proceeding with Future ML112640419
Level 3 Probabilistic Risk Assessment (PRA)
Activities''...........................................
Level 3 PRA Project, Volume 3x: Overview of Reactor, At- ML22067A210
Power, Level 1, 2, and 3 PRAs for Internal Events and
Internal Floods; Draft Report for Comment..............
Level 3 PRA Project, Volume 3a: Reactor, At-Power, Level ML22067A211
1 PRA for Internal Events, Part 1--Main Report.........
Level 3 PRA Project, Volume 3a: Reactor, At-Power, Level ML22067A212
1 PRA for Internal Events, Part 2--Appendices..........
Level 3 PRA Project, Volume 3b: Reactor, At-Power, Level ML22067A213
1 PRA for Internal Flooding............................
Level 3 PRA Project, Volume 3c: Reactor, At-Power, Level ML22067A214
2 PRA for Internal Events and Floods...................
Level 3 PRA Project, Volume 3d: Reactor, At-Power, Level ML22067A215
3 PRA for Internal Events and Floods...................
Level 3 PRA Project, Volume 2: Background, Site and ML22067A232
Plant Description, and Technical Approach..............
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Dated: April 19, 2022.
For the Nuclear Regulatory Commission.
John A. Nakoski,
Chief, Probability Risk Assessment Branch, Division of Risk Analysis,
Office of Nuclear Regulatory Research.
[FR Doc. 2022-08617 Filed 4-21-22; 8:45 am]
BILLING CODE 7590-01-P