ML22333A007
| ML22333A007 | |
| Person / Time | |
|---|---|
| Issue date: | 12/08/2022 |
| From: | Lingham S, Reinaldo Rodriguez Licensing Processes Branch |
| To: | Antonios Zoulis NRC/NRR/DRA |
| References | |
| ML22319A085 | |
| Download: ML22333A007 (1) | |
Text
December 8, 2022 MEMORANDUM TO: Antonios Zoulis, Chief PRA Oversight Branch Division of Risk Assessment Office of Nuclear Reactor Regulation FROM: Siva P. Lingam, Project Manager /RA/
Licensing Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Reinaldo Rodriguez, Senior Reactor Analyst /RA/
PRA Oversight Branch Division of Risk Assessment Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF NOVEMBER 16, 2022, PUBLIC MEETING WITH NUCLEAR ENERGY INSTITUTE, INDUSTRY, AND ELECTRIC POWER RESEARCH INSTITUTE TO SHARE RISK INSIGHTS GAINED FROM THE HIGH ENERGY ARCING FAULTS LIC-504 ASSESSMENT On November 16, 2022, the U.S. Nuclear Regulatory Commission (NRC) staff held an observation public meeting with representatives from the Nuclear Energy Institute (NEI),
Industry, and the Electric Power Research Institute (EPRI) to share and exchange the information pertaining to the NRC staffs results, including risk insights as a result of the staffs evaluation of safety significance of high energy arcing faults (HEAF) using the Office of Nuclear Reactor Regulations Office Instruction LIC-504, Integrated Risk-Informed Decision-making Process for Emergent Issues, as documented in the NRC HEAF Working Groups memorandum dated July 22, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22200A272). A list of attendees is provided in Enclosure 1.
The slides presented for this public meeting are available in ADAMS under Accession No. ML22319A085. A list of the panel members representing the NRC, Constellation, and Duke-Energy is included in Enclosure 2. A list of presenters is included in Enclosure 3. The details of the meeting are discussed in Enclosure 4.
During the public comment period, members of public provided comments. Some of the significant comments pertained to: (a) LIC-504 team conclusion relating to risk significance of the issue, (b) accuracy of quantifications of the accident sequence precursor results of previous HEAF related events and conditions, (c) timing and the quality of the LIC-504 teams conclusion with respect to whether an immediate safety concern exists, and (d) adequacy of using results from the two reference plants can be considered as bounding the HEAF risks at US plants. In response to these questions, the NRC staff provided additional information and clarification, and committed to follow up as appropriate after evaluating the comments and questions.
A. Zoulis No regulatory decisions or commitments were made at the meeting.
Please direct any inquiries to me at (301) 415-1564 or by e-mail at Siva.Lingam@nrc.gov, or Reinaldo Rodriguez at (404) 997-4498 or by e-mail at Reinaldo.Rodriguez@nrc.gov.
Enclosures:
- 1. List of Attendees
- 2. List of Panel Members
- 3. List of Presenters
- 4. Meeting Details
LIST OF ATTENDEES NOVEMBER 16, 2022, PUBLIC MEETING WITH NUCLEAR ENERGY INSTITUTE, INDUSTRY, AND ELECTRIC POWER RESEARCH INSTITUTE TO SHARE RISK INSIGHTS GAINED FROM THE HIGH ENERGY ARCING FAULTS LIC-504 ASSESSMENT Name Affiliation Christian Araguas U.S. Nuclear Regulatory Commission (NRC)
Mike Franovich NRC Kenneth Hamburger NRC John Hanna NRC John Hughey NRC J.S. Hyslop NRC Meena Khanna NRC Michelle Kichline NRC Andrea Kock NRC Matthew Leech NRC Siva Lingam NRC Lauren Mayros NRC Shivani Mehta NRC Nick Melly NRC Andrew Mihalik NRC Ed Miller NRC Charles Moulton NRC Ching Ng NRC Lundy Pressley NRC Jay Robinson NRC Reinaldo Rodriguez NRC MarkHenry Salley NRC David Stroup NRC John Tappert NRC Gabe Taylor NRC Keith Tetter NRC Christopher Tyree NRC Shilp Vasavada NRC Sunil Weerakkody NRC Jennifer Whitman NRC Antonios Zoulis NRC Suzanne Loyd Constellation Kevin Lueshen Constellation Patricia Pringle Constellation Jeffrey Stone Constellation Enclosure 1
Name Affiliation Jeffrey Ertman Duke-Energy Jack Lemmer Duke-Energy Jamie McCrory Duke-Energy Robert Rishel Duke-Energy Ashley Lindeman Electric Power Research Institute (EPRI)
Ferrante Fernando EPRI Marko Randelovic EPRI Mark Woodby EPRI Victoria Anderson Nuclear Energy Institute (NEI)
Thomas Basso NEI Andrew Mauer NEI Jennifer Uhle NEI Mark Hulet Arizona Public Service Company Larry Nicholson NextEra Joshua Ross FirstEnergy Kiang Zee Wolf Creek Nuclear Operating Corporation Greg Kvamme Northern States Power Company - Minnesota Raymond Burski Florida Power & Light Company (Contractor)
Vish Patel Southern Nuclear Operating Company Ben Morse Engineering Planning and Management, Inc. (EPM)
Mark Schairer EPM Michael Szkutak EPM Travis Weber EPM Francisco Joglar Jensen Hughes Dane Lovelace Jensen Hughes Victor Ontiveros Jensen Hughes Andy Ratchford Jensen Hughes Gregory Zucal Jensen Hughes Tom Collopy United Nuclear Corporation Charles Young Retired (U.S. Navy)
David Lochbaum Retired (Union of Concerned Scientists)
Jeff Mitman Retired (NRC)
Paul Gunter Beyond Nuclear Roberto Herrero Santos Consejo de Seguridad Nuclear (CSN), Spain Juan Manuel Martin Valdepenas CSN, Spain U.S. Senate Environment and Public Works Andrew Zach Committee
LIST OF PANEL MEMBERS NOVEMBER 16, 2022, PUBLIC MEETING WITH NUCLEAR ENERGY INSTITUTE, INDUSTRY, AND ELECTRIC POWER RESEARCH INSTITUTE TO SHARE RISK INSIGHTS GAINED FROM THE HIGH ENERGY ARCING FAULTS LIC-504 ASSESSMENT Name Affiliation Suzanne Loyd Constellation Robert Rishel Duke-Energy Reinaldo Rodriguez U.S. Nuclear Regulatory Commission (NRC)
Sunil Weerakkody NRC Antonios Zoulis* NRC
- Facilitator Enclosure 2
LIST OF PRESENTERS NOVEMBER 16, 2022, PUBLIC MEETING WITH NUCLEAR ENERGY INSTITUTE, INDUSTRY, AND ELECTRIC POWER RESEARCH INSTITUTE TO SHARE RISK INSIGHTS GAINED FROM THE HIGH ENERGY ARCING FAULTS LIC-504 ASSESSMENT Name Affiliation Mike Franovich U.S. Nuclear Regulatory Commission (NRC)
Jack Lemmar Duke-Energy Suzanne Loyd Constellation Reinaldo Rodriguez NRC Sunil Weerakkody NRC Enclosure 3
MEETING DETAILS NOVEMBER 16, 2022, PUBLIC MEETING WITH NUCLEAR ENERGY INSTITUTE, INDUSTRY, AND ELECTRIC POWER RESEARCH INSTITUTE TO SHARE RISK INSIGHTS GAINED FROM THE HIGH ENERGY ARCING FAULTS LIC-504 ASSESSMENT Purpose The purpose of this public meeting between the U.S. Nuclear Regulatory Commission (NRC) staff, and representatives from the Nuclear Energy Institute (NEI), Industry, and the Electric Power Research Institute (EPRI) was to share and exchange the information pertaining to the NRC staffs results, including risk insights as a result of the staffs evaluation of safety significance of high energy arcing faults (HEAF) using the Office of Nuclear Reactor Regulations (NRR) Office Instruction LIC-504, Integrated Risk-Informed Decision-making Process for Emergent Issues (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19253D401), as documented in the NRC HEAF Working Groups memorandum dated July 22, 2022 (ADAMS Accession No. ML22200A272).
Background
As described in its August 21, 2021, memorandum (ADAMS Accession No. ML21237A360), the NRC has exited the Generic Issues Program for HEAFs and entered a regulatory process consistent with NRR Office Instruction LIC-504. The revised approach supports a more efficient resolution of the issue using a risk-informed process and aligns with the Be RiskSMART framework. The LIC-504 evaluation used the best available HEAF technical information, along with available plant information.
The NRC staff has reviewed additional information from the ongoing Office of Nuclear Regulatory Research testing, operating experience, and collaborative research with EPRI.
The NRC staff will continue to work with EPRI under the memorandum of understanding on Fire Research to advance the state of knowledge for evaluating HEAFs in probabilistic risk assessments (PRAs).
The NRC staff assessed if any longer-term regulatory actions are justified based on the detailed LIC-504 evaluation.
Results of NRC LIC-504 Evaluation The staff assessed whether there was a need for immediate regulatory action(s) and concluded that U.S. plants remain safe without the agency taking any prompt regulatory action(s).
Enclosure 4
The staff investigated the differences in risk between the current HEAF PRA methodology and the new HEAF PRA methodology.
The staff concluded that those plants with relatively long fault clearing times, and consequently larger zones of influence for bus ducts, could experience a significant increase in risk due to HEAFs.
The staff evaluated various communication options that would enable the staff to share its insights with external stakeholders for licensee consideration to implement effective steps to further reduce and/or mitigate HEAF risks.
The staff concluded that no further regulatory actions are required and recommended to issue an Information Notice sharing the operating experience and availability of the new HEAF risk assessment methodology for licensee consideration.
Meeting Details The panel members provided the following presentations:
Suzanne Loyd of Constellation concluded her presentation with the following highlights:
HEAF scenarios in fire PRA have always been considered a significant contributor to risk.
HEAF events can be prevented or mitigated with routine maintenance of electrical equipment, operator training, and sharing of operating experience among licensees.
Shields or barriers can be used to mitigate HEAF events.
Use of improved draft methodology can provide more realistic representation of HEAF in fire PRA models.
Jack Lemmar of Duke Energy addressed the following topics:
Importance of HEAFS Prevention of HEAFS Draft methodology application Reinaldo Rodriguez of NRC/NRR presented the NRC staffs HEAF LIC-504 risk insights, one boiling water reactor and one pressurized water reactor plant visits, factors considered in LIC-504 implementation, and quoted the publicly available memorandum dated July 22, 2022, with working group recommendations (ADAMS Accession No. ML22201A000). Based on the evaluation of HEAF using LIC-504, the NRC staff concluded that there is no significant increase in total HEAF risk that warranted any additional regulatory actions. However, the NRC staff recommended to issue an Information Notice covering the LIC-504 quantitative and qualitative assessments, related operating experience, and the availability of the new HEAF PRA methodology for licensee consideration.
Sunil Weerakkody of NRC/NRR described the sources of operating experience, HEAF scenarios in fire PRA, and reducing risk with risk significant HEAF events that occur.
Packages: ML22325A300 and ML22319A085 Meeting Notice: ML22299A182 Meeting Slides: ML22319A075, ML22319A077, and ML22319A080 Meeting Summary: ML22333A007 *by e-mail OFFICE NRR/DORL/LLPB/PM* NRR/DRA/APOB/RA* NRR/DORL/LLPB/LA*
NAME SLingam RRodriguez DHarrison DATE 11/23/22 11/28/22 11/30/22 OFFICE NRR/DRA/APOB/BC
- NRR/DORL/LLPB/BC (A)* NRR/DORL/LLPB/PM*
NAME AZoulis JEvans SLingam DATE 11/30/22 12/8 /22 12/8/22