ML22158A070
| ML22158A070 | |
| Person / Time | |
|---|---|
| Issue date: | 07/25/2022 |
| From: | Markhenry Salley NRC/RES/DRA |
| To: | |
| Taylor, Gabe 415-0781 | |
| Shared Package | |
| ML22158A067 | List: |
| References | |
| NRC-2022-0130 | |
| Download: ML22158A070 (5) | |
Text
[7590- 01-P]
NUCLEAR REGULATORY COMMISSION
[NRC-2022- 0130]
High Energy Arcing Fault Hazard Frequency and Consequence Modeling
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft NUREG; request for comment.
SUMMARY
- The U.S. Nuclear Regulatory Commission (NRC) is issuing for public
comment draft NUREG-2262, High Energy Arcing Fault Frequency and Consequence
Modeling.
DATES: Submit comments by August 29, 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
webs ite:
- Federal rulemaking website: Go to https://www.regulations.gov and search
for Docket ID NRC-2022- 0130. Address questions about Docket IDs in Regulations.gov
to Stacy Schumann; telephone: 301-415-0624; email: Stacy.Schumann@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 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: Gabriel.Taylor@nrc.gov.
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2022 -0130 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 -0130.
- NRCs 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 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 NUREG-2262 High
Energy Arcing Fault Frequency and Consequence Modeling is available in ADAMS
under Accession No. ML 22158A071.
- 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 appointment to visit the PDR,
2 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. Eastern Time (ET), Monday through Friday,
except Federal holidays.
B. Submitting Comments
The NRC encourages electronic comment submission through the Federal
rulemaking webs ite (https://www.regulations.gov). Please include Docket ID NRC-
2022 -0130 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
The NRC Office of Nuclear Regulatory Research and the Electrical Power
Research Institute (EPRI) are advancing the understanding and state -of-practice for
modeling High Energy Arcing Faults (HEAF) in fire Probabilistic Risk Assessment.
NUREG/CR-6850 and NUREG/CR-6850 Supplement 1 provide the basic methods to
analyze the risk associated with HEAFs in power distribution equipment (switchgear and
load centers) and bus ducts (including iso-phase bus ducts), respectively. Since the
3 publication of these two reports, the state of knowledge of the HEAF phenomena has
advanced significantly. A thorough understanding of the nuclear power plant electrical
distribution system and its performance during faulted conditions along with a review and
categorization of industry events has occurred. Additionally, experimentation - including
full scale testing on HEAF-susceptible equipment, small scale testing, and hazard
estimation have increased the understanding of parameters that affect the dimensions of
the zone of influence (ZOI).
In draft NUREG-2262 titled, High Energy Arcing Fault Frequency and
Consequence Modeling, the NRC worked with the EPRI to combine previous HEAF-
related research, methods, and data to improve realism in calculating plant risk due to
HEAFs. Ignition frequency and non-suppression estimates are updated with the most
recently available industry operating experience. The ZOI configurations are expanded.
Previous guidance postulated one ZOI for each category of equipment (switchgear and
load centers, bus ducts, and iso-phase bus ducts). The development and use of HEAF
hazard estimation tools allowed for the expansion of ZOI configurations by using
scenario specific parameters such as fault current magnitude, arc voltage, duration,
location, electrode composition, and type of equipment, to more accurately predict the
ZOI. The ZOIs results are grouped by the working group to determine consensus ZOIs
for the three classes of equipment with varying levels of detail commensurate with
potential risk significance.
4 The information contained within the draft research information letter is expected
to be used in the future as the state-of-the-art method for characterizing the risk to
nuclear facilities from a HEAF.
Dated: July 25, 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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