ML22095A238
| ML22095A238 | |
| Person / Time | |
|---|---|
| Issue date: | 05/09/2022 |
| From: | Markhenry Salley NRC/RES/DRA |
| To: | |
| Taylor, Gabriel 301-415-0781 | |
| Shared Package | |
| ML22095A226 | List: |
| References | |
| Download: ML22095A238 (5) | |
Text
[7590-01-P]
NUCLEAR REGULATORY COMMISSION
[NRC-2022-0096]
Modeling High Energy Arcing Fault Hazards and Zones of Influenc e
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft research information letter reports; request for comment.
SUMMARY
- The U.S. Nuclear Regulatory Commission (NRC) is issuing for pub lic
comment two draft Research Information Letter reports, Predict ing High Energy Arcing
Fault Zones of Influence for Aluminum Using a Modified Arc Flas h Model, Evaluation of
a modified model bias, uncertainty, parameter sensitivity and z one of influence
estimation, Draft for public comment, and Determining the Zon e of Influence for High
Energy Arcing Faults using Fire Dynamics Simulator, Draft for p ublic comment.
DATES: Submit comments by [INSERT DATE 30 DAYS AFTER PUBLICATION IN
THE FEDERAL REGISTER]. Comments received after this date will be considered if it
is practical to do so, but the Commission is able to ensure con sideration only for
comments received on or before this date.
ADDRESSES: You may submit comments by any of the following methods; howe ver,
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: Stacy.Schu mann@nrc.gov. 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 submittin g 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, Washin gton, DC 20555-
0001, telephone: 301-415-0781, email: Gabriel.Taylor@nrc.gov.
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 pu blicly 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.
- NRCs Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly available documents online in the ADA MS Public
Documents collection at https://www.nrc.gov/reading-rm/adams.ht ml. To begin the
search, select Begin Web-based ADAMS Search. For problems wi th ADAMS, please
contact the NRCs Public Document Room (PDR) reference staff at 1-800-397-4209,
301-415-4737, or by email to PDR.Resource@nrc.gov. The draft r esearch information
letter reports Predicting High Energy Arcing Fault Zones of In fluence for Aluminum
Using a Modified Arc Flash Model, Evaluation of a modified mode l bias, uncertainty,
2 parameter sensitivity and zone of influence estimation, Draft f or public comment is
available in ADAMS under Accession No. ML22095A236, and Determ ining the Zone of
Influence for High Energy Arcing Faults using Fire Dynamics Sim ulator, Draft for public
comment, is available in ADAMS under Accession No. ML22095A237.
- NRCs PDR: You may examine and purchase copies of public documents,
by appointment, at the NRCs PDR, Room P1 B35, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852. To make an appointm ent to visit the PDR,
please send an email to PDR.Resource@nrc.gov or call 1-800-397-4209 or 301-415-
4737, between 8:00 a.m. and 4:00 p.m. (ET), Monday through Frid ay, 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 info rmation 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 e nter the comment
submissions into ADAMS. The NRC does not routinely edit commen t submissions to
remove identifying or contact information.
If you are requesting or aggregating comments from other person s 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 dis closed in their comment
submission. Your request should state that the NRC does not routinely edit comment
submissions to remove such information before making the commen t submissions
3 available to the public or entering the comment into ADAMS. Al l comments should
reference the applicable report.
II. Discussion
The NRC Office of Nuclear Regulatory Research (RES) is advancin g the
understanding and state-of-practice for modeling High Energy Ar cing 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 scenari os important for nuclear
safety. The high intensity and short duration of a HEAF has no t been explicitly modeled
in past fire PRA methodologies. As such, there was a need to a dvance HEAF modeling
capabilities to reliably predict the scenario specific HEAF haz ards to support refinements
to the zones of influence (ZOI) used in fire PRA. The NRC work ed with its collaborative
research partners to develop two models to predict the HEAF haz ard.
In the report titled, Predicting High Energy Arcing Fault Zone s of Influence for
Aluminum Using a Modified Arc Fl ash Model, Evaluation of a modi fied model bias,
uncertainty, parameter sensitivity and zone of influence estima tion, Draft for public
comment, the NRC worked with Sandia National Laboratories to e valuate an existing
base model. Differences between the base model and nuclear pow er plant fire PRA
scenarios were identified. Modification of the base model esta blished from existing
literature and test data was used to minimize these differences. The modified model
was evaluated against NRC datasets to understand the model pred iction and relative
uncertainties. Finally, a range of fire PRA ZOIs were develope d based on the modified
model and draft update HEAF PRA methodology. The results are e xpected to be used
to inform an update to ZOIs used in fire PRA.
In the report titled, Determining the Zone of Influence for Hi gh Energy Arcing
Faults using Fire Dynamics Simulator, Draft for public comment, the NRC worked with
4 the Electric Power Research Institute and the National Institut e 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 docume nts (1) the
development of the approach to use FDS to predict thermal expos ures to targets from a
HEAF, (2) validation of the model and (3) application of the mo del to estimate HEAF ZOI
for a broad range of fire PRA HEAF scenarios.
The draft research information letter reports present the NRC-R ES/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 estim ating the hazard
ZOI. For most scenarios the two approaches provide results tha t 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-RE S/EPRI report provides
additional geometric detail to the ZOI estimate.
Dated: May 9, 2022.
For the Nuclear Regulatory Commission.
/RA/
Mark H. Salley, Chief, Fire and External Hazards Analysis Branch, Division of Risk Analysis, Office of Nuclear Regulatory Research.
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