[Federal Register Volume 86, Number 227 (Tuesday, November 30, 2021)] [Notices] [Pages 67983-67984] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2021-26018] ----------------------------------------------------------------------- NUCLEAR REGULATORY COMMISSION [NRC-2021-0213] Target Fragilities for Equipment Vulnerable to High Energy Arcing Faults AGENCY: Nuclear Regulatory Commission. ACTION: Draft research information letter; request for comment. ----------------------------------------------------------------------- SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment draft research information letter, ``Target Fragilities for Equipment Vulnerable to High Energy Arcing Faults, Draft Report for Comment.'' DATES: Submit comments by December 30, 2021. 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-2021-0213. 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-2021-0213 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-2021-0213. 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 Report ``Target Fragilities for Equipment Vulnerable to High Energy Arcing Faults, Draft Report for Comment'' is available in ADAMS under Accession No. ML21326A010. 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 [[Page 67984]] Docket ID NRC-2021-0213 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 (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 to understand the HEAF effects on equipment important for nuclear safety. The high intensity and short duration of a HEAF exposure causes substantially different heat transfer conditions than a classical thermal fire case. As such, there was a need to develop HEAF specific damage and ignition limits to support advancements. The NRC collaborated with the Electric Power Research Institute (EPRI) to develop technical consensus positions on the damage and ignition limits of equipment important to plant safety and commonly evaluated in fire PRAs. The target fragility limits are based on operating experience, small and large scale testing, lessons learned from a Phenomena Identification and Ranking Table exercise, results from analytical tools, and judgement. The draft research information letter presents the NRC-RES/EPRI working groups consensus on the damage and ignition limits of nuclear facility targets that are important to safety. It includes specific energy fluence levels that cause damage to components such as electrical cables, cable protective features, and non-segregated phase bus ducts. The conclusions from this report will be used in conjunction with HEAF hazard estimates to develop zones of influence to support improvements to fire PRA methods. Dated: November 24, 2021. 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. 2021-26018 Filed 11-29-21; 8:45 am] BILLING CODE 7590-01-P