[Federal Register Volume 87, Number 93 (Friday, May 13, 2022)]
[Notices]
[Pages 29395-29396]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-10323]
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NUCLEAR REGULATORY COMMISSION
[NRC-2022-0096]
Modeling High Energy Arcing Fault Hazards and Zones of Influence
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft research information letter reports; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment two draft Research Information Letter reports,
``Predicting High Energy Arcing Fault Zones of Influence for Aluminum
Using a Modified Arc Flash Model, Evaluation of a modified model bias,
uncertainty, parameter sensitivity and zone of influence estimation,
Draft for public comment,'' and ``Determining the Zone of Influence for
High Energy Arcing Faults using Fire Dynamics Simulator, Draft for
public comment.''
DATES: Submit comments by June 13, 2022. 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 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-2022-0096. 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: Gabriel J. Taylor, Office of Nuclear
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, telephone: 301-415-0781, email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2022-0096 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-2022-0096.
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 research information letter
reports ``Predicting High Energy Arcing Fault Zones of Influence for
Aluminum Using a Modified Arc Flash Model, Evaluation of a modified
model bias, uncertainty, parameter sensitivity and zone of influence
estimation, Draft for public comment'' is available in ADAMS under
Accession No. ML22095A236, and ``Determining the Zone of Influence for
[[Page 29396]]
High Energy Arcing Faults using Fire Dynamics Simulator, Draft for
public comment,'' is available in ADAMS under Accession No.
ML22095A237.
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-2022-0096 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. All comments should
reference the applicable report.
II. Discussion
The NRC Office of Nuclear Regulatory Research (RES) is advancing
the understanding and state-of-practice for modeling High Energy Arcing
Faults (HEAF) in fire Probabilistic Risk Assessment (PRA). One
important aspect of this research is the ability to reliably predict
the HEAF hazard for various scenarios important for nuclear safety. The
high intensity and short duration of a HEAF has not been explicitly
modeled in past fire PRA methodologies. As such, there was a need to
advance HEAF modeling capabilities to reliably predict the scenario
specific HEAF hazards to support refinements to the zones of influence
(ZOI) used in fire PRA. The NRC worked with its collaborative research
partners to develop two models to predict the HEAF hazard.
In the report titled, ``Predicting High Energy Arcing Fault Zones
of Influence for Aluminum Using a Modified Arc Flash Model, Evaluation
of a modified model bias, uncertainty, parameter sensitivity and zone
of influence estimation, Draft for public comment,'' the NRC worked
with Sandia National Laboratories to evaluate an existing base model.
Differences between the base model and nuclear power plant fire PRA
scenarios were identified. Modification of the base model established
from existing literature and test data was used to minimize these
differences. The modified model was evaluated against NRC datasets to
understand the model prediction and relative uncertainties. Finally, a
range of fire PRA ZOIs were developed based on the modified model and
draft update HEAF PRA methodology. The results are expected to be used
to inform an update to ZOIs used in fire PRA.
In the report titled, ``Determining the Zone of Influence for High
Energy Arcing Faults using Fire Dynamics Simulator, Draft for public
comment,'' the NRC worked with the Electric Power Research Institute
and the National Institute of Standards and Technology to adapt a
computational fluid dynamic code known as the Fire Dynamics Simulator
(FDS) to predict the HEAF hazard. This report documents (1) the
development of the approach to use FDS to predict thermal exposures to
targets from a HEAF, (2) validation of the model and (3) application of
the model to estimate HEAF ZOI for a broad range of fire PRA HEAF
scenarios.
The draft research information letter reports present the NRC-RES/
Sandia National Laboratories (SNL) and NRC-RES/Electric Research Power
Institute (EPRI) working groups efforts to predict realistic HEAF
hazards. The two approaches to model HEAF hazards present complementary
but diverse methods to estimating the hazard ZOI. For most scenarios
the two approaches provide results that are consistent with each other.
The NRC-SNL report can be viewed as a first order approximation
providing a single value scenario specific ZOI estimate, while the NRC-
RES/EPRI report provides additional geometric detail to the ZOI
estimate.
Dated: May 9, 2022.
For the Nuclear Regulatory Commission.
Mark H. Salley,
Chief, Fire and External Hazards Analysis Branch, Division of Risk
Analysis, Office of Nuclear Regulatory Research.
[FR Doc. 2022-10323 Filed 5-12-22; 8:45 am]
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