[Federal Register Volume 87, Number 77 (Thursday, April 21, 2022)]
[Notices]
[Pages 23891-23892]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-08519]
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NUCLEAR REGULATORY COMMISSION
[NRC-2021-0179]
Alternative Radiological Source Terms for Evaluating Design Basis
Accidents at Nuclear Power Reactors
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft regulatory guide; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment a draft regulatory guide (DG), DG-1389, ``Alternative
Radiological Source Terms for Evaluating Design Basis Accidents at
Nuclear Power Reactors.'' This DG is proposed Revision 1 to Regulatory
Guide (RG) 1.183 which describes a method that the NRC staff considers
acceptable in complying with regulations for design basis accident dose
consequence analysis using an Alternative Source Term. This guidance
for light-water reactor (LWR) designs includes the scope, and
documentation of associated analyses and evaluations; consideration of
impacts on analyzed risk; and content of submittals.
DATES: Submit comments by June 21, 2022. 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;
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-2021-0179. Address
questions about Docket IDs in Regulations.gov to Stacy Schumann;
telephone: 301-415-0624; email: [email protected]. For technical
questions, contact the individuals 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: Michael Eudy, Office of Nuclear
Regulatory Research, telephone: 301-415-3104, email:
[email protected]; and Mark Blumberg, Office of Nuclear Reactor
Regulation, telephone: 301-415-1083, email: [email protected]. Both
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001.
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2021-0179 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-2021-0179.
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]. The ADAMS accession number for each
document referenced (if it is available in ADAMS) is provided the first
time that it is mentioned in this document.
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-2021-0179 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. Additional Information
The NRC is issuing for public comment a DG in the NRC's
``Regulatory Guide'' series. This series was developed to describe
methods that are acceptable to the NRC staff for implementing specific
parts of the agency's regulations, to explain techniques that the staff
uses in evaluating specific issues or postulated events, and to
describe information that the staff needs in its review of applications
for permits and licenses.
The DG, entitled ``Alternative Radiological Source Terms for
Evaluating Design Basis Accidents at Nuclear Power Reactors,'' (ADAMS
Accession No. ML21204A065) is temporarily identified by its task
number, DG-1389 which is proposed
[[Page 23892]]
Revision 1 of RG 1.183 of the same name. This revision of the guide
(Revision 1) addresses new issues identified since the guide was
originally issued. These include (1) using the term maximum
hypothetical accident (MHA) loss-of-coolant accident (LOCA) to define
the accident described in regulation, (2) adding transient release
fractions from empirical data from in-pile, prompt power pulse test
programs and analyses from several international publications of fuel
rod performance under prompt power excursion conditions, (3) revising
steady-state release fractions for accidents other than the LOCA based
on a revision to the American National Standards Institute/American
Nuclear Society Standard 5.4, ``Method for Calculating the Fractional
Release of Volatile Fission Products from Oxide Fuel,'' (4) adding
information to acknowledge the proposed Revision 1 may provide useful
information for satisfying the radiological dose analysis requirements
in part 50 of title 10 of the Code of Federal Regulations (10 CFR),
``Domestic Licensing of Production and Utilization Facilities'' and 10
CFR part 52, ``Licenses, Certifications, and Approvals for Nuclear
Power Plants,'' for advanced LWR design and siting, (5) providing
additional guidance for modeling boiling-water reactor (BWR) main steam
isolation valve (MSIV) leakage, (6) adding guidance for accident
tolerant fuel, high-burnup fuel, and increased enrichment source term
analyses, (7) revising transport and decontamination models for the
fuel handling design basis accident, (8) adding guidance for crediting
holdup and retention of MSIV leakage within the main steam lines and
condenser for BWRs, and (9) providing additional meteorological
assumption guidance.
On October 14, 2009, the NRC staff issued DG-1199, ``Alternative
Radiological Source Terms for Evaluating Design Basis Accidents at
Nuclear Power Reactors,'' (ADAMS Accession No. ML090960464), for public
comment (74 FR 52822). DG-1199 was a proposed Revision 1 to RG 1.183.
The NRC staff has elected not to finalize DG-1199 and is issuing DG-
1389 as a replacement. The staff notes that DG-1389 addresses technical
issues and considered public comments related to the issuance of DG-
1199.
The staff is also issuing for public comment a draft regulatory
analysis (ADAMS Accession No. ML21204A066). The staff developed a
regulatory analysis to assess the value of issuing or revising a
regulatory guide as well as alternative courses of action.
III. Backfitting, Forward Fitting, and Issue Finality
The NRC staff may use this RG, if finalized, as a reference in its
regulatory processes, such as licensing, inspection, or enforcement.
However, the NRC staff does not intend to use the guidance in this RG
to support NRC staff actions in a manner that would constitute
backfitting as that term is defined in 10 CFR 50.109, ``Backfitting,''
and as described in NRC Management Directive (MD) 8.4, ``Management of
Backfitting, Forward Fitting, Issue Finality, and Information
Requests'' (ADAMS Accession No. ML18093B087), nor does the NRC staff
intend to use the guidance to affect the issue finality of an approval
under 10 CFR part 52. The staff also does not intend to use the
guidance to support NRC staff actions in a manner that constitutes
forward fitting as that term is defined and described in MD 8.4. If a
licensee believes that the NRC is using this RG in a manner
inconsistent with the discussion in this Implementation section, then
the licensee may file a backfitting or forward fitting appeal with the
NRC in accordance with the process in MD 8.4.
IV. Specific Request for Comment
In addition to the general request for comments on DG-1389, the NRC
is also seeking specific comments on a draft staff technical assessment
titled, ``Technical Assessment of Hold-up and Retention of Main Steam
Isolation Valve Leakage within the Main Steam Lines and Main
Condenser'' (ADAMS Accession No. ML20085J042) that is referenced in the
draft revised guidance. The technical assessment provides the proposed
technical basis for the low risk of gross failure of the alternate
pathway to the condenser at seismic accelerations at or below a plant's
design basis safe shutdown earthquake, as described in DG-1389. The
technical assessment also supports a proposed streamlined approach in
DG-1389 for demonstrating the seismic capacity of structures, systems,
and components in the alternate pathway, compared to the approach in RG
1.183, Revision 0 (ADAMS Accession No. ML003716792).
V. Submitting Suggestions for Improvement of Regulatory Guides
A member of the public may, at any time, submit suggestions to the
NRC for improvement of existing RGs or for the development of new RGs.
Suggestions can be submitted on the NRC's public website at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html.
Suggestions will be considered in future updates and enhancements to
the ``Regulatory Guide'' series.
Dated: April 18, 2022.
For the Nuclear Regulatory Commission.
Meraj Rahimi,
Chief, Regulatory Guide and Programs Management Branch, Division of
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2022-08519 Filed 4-20-22; 8:45 am]
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