[Federal Register Volume 85, Number 1 (Thursday, January 2, 2020)]
[Notices]
[Pages 143-144]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-28323]
[[Page 143]]
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NUCLEAR REGULATORY COMMISSION
[NRC-2019-0229]
Methodology for Modeling Transient Fires in Nuclear Power Plant
Fire Probabilistic Risk Assessments
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft NUREG; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment a draft NUREG entitled, ``Methodology for Modeling
Transient Fires in Nuclear Power Plant Fire Probabilistic Risk
Assessments'' (NUREG-2233/EPRI 3002016054). This report is a joint
product of the NRC and the Electric Power Research Institute (EPRI)
collaborating under a memorandum of understanding for fire research.
This report contains a methodology to increase the realism in the
modeling of transient ignition sources in fire probabilistic risk
assessment (FPRA). Additionally, the report develops a method for the
detailed modeling of transient fires that includes fire growth and
decay parameters, yields of minor products of combustion, heat of
combustion, and the physical size and effective elevation of the fire.
DATES: Submit comments by February 18, 2020. Comments received after
this date will be considered if it is practical to do so, but the
Commission is able to ensure consideration only for comments received
before this date.
ADDRESSES: You may submit comments by any of the following methods:
Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2019-0229. Address
questions about Docket IDs in Regulations.gov to Jennifer Borges;
telephone: 301-287-9127; 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: David W. Stroup, Office of Nuclear
Regulatory Research, telephone: 301-415-1649, email:
[email protected]; or Nicholas Melly, Office of Nuclear Regulatory
Research, telephone: 301-415-2392, 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-2019-0229 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-2019-0229.
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 draft NUREG on ``Methodology for
Modeling Fire Growth and Suppression Response of Electrical Cabinet
Fires in Nuclear Power Plants'' is available in ADAMS under Accession
No. ML19357A270.
NRC's PDR: You may examine and purchase copies of public
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852.
B. Submitting Comments
Please include Docket ID NRC-2019-0229 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
In 2005, the Electric Power Research Institute (EPRI) and the NRC's
Office of Nuclear Regulatory Research (RES) issued a joint technical
report titled, EPRI/NRC-RES, Fire PRA Methodology for Nuclear Power
Facilities, EPRI 1011989, NUREG/CR-6850. This publication documented
state-of-the-art methods, tools, and data for conducting a fire
probabilistic risk assessment (FPRA) for a commercial nuclear power
plant (NPP) application. Following this publication, many utilities
developed FPRAs using the guidance in NUREG/CR-6850 to support risk
informed applications, including the transition to an NFPA 805
licensing basis, among others. The results obtained from the FPRA
models have suggested specific elements in the fire scenario analysis
where improved methods and/or guidance could reduce conservatism and
increase realism in the risk estimates. Consequently, over the past
fifteen years, FPRA research covering the areas of fire ignition
frequencies, fire modeling, human reliability analysis and spurious
operations have been published. These research results have improved
realism for the ignition sources identified in NUREG/CR-6850 except for
transient combustibles. The research in this report addresses that gap.
The research documented in this report was developed by a working
group that included members of both the regulator and the nuclear power
industry and consisted of two phases. For the first phase, an extensive
set of experiments measuring the heat release rate and other fire
characteristics of transient fires was conducted to supplement the
existing data in NUREG/CR-6850/EPRI 1011989. The test report for this
set of experiments, NUREG-2232/EPRI 3002015997, ``Heat Release Rate and
Fire Characteristics of Fuels Representative of Typical Transient Fire
Events in Nuclear Power Plants,'' contains details on all the fuel
packages tested; the test method including selection of fuel packages
and ignition sources; the methods used to process the collected test
data; and the collected and derived data including heat release rate,
fire diameter, zones of influence, fire growth and decay parameters,
and the combustion properties of the fuel packages. The test report is
available from EPRI at https://www.epri.com/#/pages/product/
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3002015997/. The second phase, documented in this report, combined the
data collected in the first phase with data from previous experimental
programs, developed a methodology for weighting the combined dataset
based on industry experience with transient fires, and used the
weighted combined dataset to create improved probabilistic
distributions for use in modeling transient fires in FPRA.
Additionally, this report presents detailed guidance for modeling the
time-dependence and defining the combustion characteristics of
transient fires.
Dated at Rockville, Maryland, this 27th day of December 2019.
For the Nuclear Regulatory Commission.
David W. Stroup,
Acting Branch Chief, Fire and External Hazards Branch, Division of Risk
Analysis, Office of Nuclear Regulatory Research.
[FR Doc. 2019-28323 Filed 12-31-19; 8:45 am]
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