ML23328A141
| ML23328A141 | |
| Person / Time | |
|---|---|
| Site: | Electric Power Research Institute |
| Issue date: | 01/16/2024 |
| From: | Lois James Licensing Processes Branch |
| To: | Gerond George Licensing Processes Branch |
| Shared Package | |
| ML23328A141:ML23328A093 | List: |
| References | |
| EPID L-2023-LRM-0096 pre-app, EPID L-2023-LRM-0096 | |
| Download: ML23328A141 (1) | |
Text
Enclosure 1 U.S. Nuclear Regulatory Commission Public Meeting Summary Open Portion
Title:
Pre-Submittal Meeting with the Electric Power Research Institute to Discuss the Use of the Alternative Licensing Strategy to Address Loss-of-Coolant Accident Induced Fuel Fragmentation, Relocation and Dispersal Date of Meeting: November 8, 2023, 1:00 pm - 5:00 pm Location: Hybrid Type of Meeting: This was a partially closed meeting. Certain portions of this meeting will be closed to the public because the staff has determined that the information is proprietary in nature. Members of the public were given an opportunity to observe the U.S. Nuclear Regulatory Commission (NRC) performing its regulatory function or discussing regulatory issues during the open portion. Attendees had an opportunity to ask questions of the NRC staff or make comments about the issues discussed following the business portion of the open portion; however, the NRC is not actively soliciting comments toward regulatory decisions at this meeting.
Purpose of the Meeting:
To discuss the licensing schedule and technical aspects of Electric Power Research Institute's (EPRI's) use of its Alternative Licensing Strategy (ALS) to address loss-of-coolant accident (LOCA) induced fuel fragmentation, relocation, and dispersal (FFRD).
General Details:
The NRC staff held a partially closed portion with EPRI to discuss the licensing schedule and technical aspects of EPRI use of its ALS to address LOCA induced FFRD. The open portion of the meeting began at 1:00 pm and ended at 2:45 pm. There were twenty-six NRC staff members, four EPRI representatives, one Nuclear Energy Institute (NEI) member, seventeen industry members, and three members of the public in the open portion of the meeting. The closed portion of the meeting began at 3:00 pm and ended at 4:30 pm. There were twenty NRC staff members, two EPRI representatives, one NEI member, ten industry members, and no members of the public in the closed portion of the meeting. The meeting portions began with introductions.
Summary of Open Meeting:
Topical Report Structure and Project Plan The EPRI representatives began by explaining that the ALS Topical Report (TR) will address four areas:
Justification for use of leak-before-break (LBB) regulatory framework/risk evaluation and defense in depth Non-piping LOCA evaluation for comparison to intermediate break LOCA (IBLOCA) and structural performance Small break LOCA (SBLOCA) and IBLOCA evaluation of FFRD and high burnup effects on FFRD Applicability requirements Extremely low probability of rupture (xLPR) probabilistic fracture mechanics LOCA frequency confirmation and time between leak detection and large-break LOCA (LBLOCA) will feed into the justification for use of LBB regulatory framework/risk evaluation and defense in depth.
The current analysis scope applies to Westinghouse Electric Company (WEC) 2, 3, and 4 loop plants operating WEC supplied fuel. Modular analysis approach supports extension to other LOCA analysis methods and fuel designs and other nuclear steam supply systems configurations depending on industry demand.
EPRI plans to submit information justifying the acceptability of the submittal with a variance from Office of Nuclear Reactor Regulation (NRR) Office Instruction (OI) LIC-109, Acceptance Review Procedures for Licensing Basis Changes, Revision 3. Specifically, LIC-109 requires that requested licensing action (RLA) should not be accepted for NRC review and approval until all requisite RLAs have been reviewed and approved by the NRC. For this TR, the LOCA method extensions are linked to ALS TR and are based on the WEC Full Spectrum (FSLOCAtm) evaluation model. These extensions will be submitted separately by WEC for concurrent review.
EPRI representatives explained that the xLPR probabilistic fracture mechanics analysis system which was jointly developed by EPRI and the NRC Office of Regulatory Research (RES) and documented in NUREG-2247, Extremely Low Probability of Rupture Version 2 Probabilistic Fracture Mechanics Code (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21225A736), will also be submitted as a linked RLA. Finally, EPRI representatives explained that the ALS method relies on the LBB evaluation method to address FFRD for LBLOCA scenarios.
Regarding the previous fee waiver, EPRI acknowledged receiving the denial dated August 30, 2023 (ADAMS Accession No. ML23212A933) that stated:
considering that the Topical Reports will not be submitted for review and endorsement until late 2023 or early 2024, there is insufficient information at this time to make a determination whether the information would assist in generic regulatory improvements or efforts.
EPRI representatives stated that EPRI intends to resubmit the fee exemption for the staffs review of the ALS TR based on Title 10 of the Code of Federal Regulation (10 CFR)
Paragraph 170.11(a)(1)(ii) which states No application fees, license fees, renewal fees, inspection fees, or special project fees shall be required for A special project that is a request/report submitted to the NRC When the NRC, at the time the request/report is submitted, plans to use the information to assist the NRC in generic regulatory improvements or efforts (e.g., rules, regulatory guides, regulations, policy statements, generic letters, or bulletins)
EPRI representatives stated that EPRI plans to submit three reports approximately March 31, 2024:
xLPR analysis (non-proprietary)
SBLOCA and IBLOCA analysis results (proprietary and non-proprietary)
ALS overview (non-proprietary)
Separately, WEC will be submitting the WEC LOCA methods extension for FFRD for NRC review and approval.
EPRI representatives further stated that there could be advantages to industry and the NRC if the NRC issued separate safety evaluations for xLPR and ALS.
Use of the xLPR Code for Developing LOCA Frequency Estimates As background, EPRI representatives explained that the xLPR is a state-of-the-art probabilistic fracture mechanics code jointly developed by the NRCs RES and EPRI. The code provides new quantitative capabilities to analyze the risks (e.g., leakage or rupture) associated with nuclear power plant piping systems subject to active degradation mechanisms.
EPRI representatives summarized the xLPR Analysis Cases and concluded that the results of the xLPR analysis demonstrate that there is sufficient time between detectable leakage and LBLOCA to shut down the reactor and prevent LBLOCA. The results further demonstrate the significant benefits of in-service inspection and leak rate detection. Finally, the final report will include applicability criteria for these conclusions.
ALS TR was developed to address FFRD which involves multiple phenomena potentially induced in high burnup (HBU) reactor fuel by LBLOCAs. The purpose of the ALS TR is to provide a generic methodology, consistent with established regulatory guidance to maximum extent possible and with risk insights, for licensees to reference to achieve timely and efficient preparation of license amendment requests to raise reactor fuel burnup limit to 75 GWd/MTU peak rod average.
Conclusion EPRI representatives stated that ALS is consistent with NRC precedents and guidance, but no existing regulations nor guidance specifically address FFRD.
Public Participation Themes:
No member of the public spoke during the open portion of the meeting and no member of the public was in attendance during the closed portion.
Action Items/Next Steps:
The NRC staff will prepare and issue a meeting summary.
Attachments:
Meeting description and agenda - ADAMS Accession No. ML23299A247 Vendor slide presentation for open meeting - ADAMS Accession No. ML23312A005 Vendor non-proprietary slide presentation for closed meeting - ADAMS Accession No. ML23312A016