ML25049A044

Nonproprietary - Final RAIs for EPRI Report 3002028675(NP)/3002028674(P), LOCA Analysis of FFRD for W 2-Loop, 3-Loop and 4-Loop Plants - Proprietary, Evaluation of Cladding Rupture in High Burnup Fuel Rods Susceptible to Fine Fragmentation,

ML25049A044
Person / Time
Site:	Electric Power Research Institute
Issue date:	02/26/2025
From:	Licensing Processes Branch
To:
References
EPRI TR 3002028674, EPRI TR 3002028675, EPID L-2024-TOP-0015 pre-fee, EPID L-2024-NTR-0003 post-fee
Download: ML25049A044 (1)

Text

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 1

OFFICIAL USE ONLY - PROPRIETARY INFORMATION REQUESTS FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REVIEW OF EPRI REPORT NOS. 3002028674/5. LOCA [LOSS-OF-COOLANT ACCIDENT]

ANALYSIS OF FUEL FRAGMENTATION, RELOCATION, AND DISPERSAL [FFRD] FOR WESTINGHOUSE 2-LOOP, 3-LOOP AND 4-LOOP PLANTS - PROPRIETARY, EVALUATION OF CLADDING RUPTURE IN HIGH BURNUP FUEL RODS SUSCEPTIBLE TO FINE FRAGMENTATION, REVISION 0 ELECTRIC POWER RESEARCH INSTITUTE DOCKET NO. 99902021 ISSUE DATE: TBD

Background

By letter dated April 26, 2024 (Agencywide Documents Access and Management System Accession No. ML24121A203), Electric Power Research Institute (EPRI) submitted EPRI Report 3002028674 (P)/3002028675 (NP), "LOCA Analyses of Fuel Fragmentation, Relocation, and Dispersal for Westinghouse 2-Loop, 3-Loop, and 4-Loop Plants - Proprietary, Evaluation of Cladding Rupture in High Burnup Fuel Rods susceptible to Fine Fragmentation," (henceforth EPRI Report 3002028674/5) to the U.S. Nuclear Regulatory Commission (NRC) for review and approval. EPRI Report 3002028674/5 proposes to demonstrate acceptable performance for LOCA-induced FFRD phenomena in high burnup pressurized water reactor (PWR) fuel by developing bounding composite models and utilizing the cladding rupture methodology proposed in WCAP-18850-P/NP, Revision 0, "Adaptation of the FULL SPECTRUM LOCA (FSLOCA) Evaluation Methodology to Perform Analysis of Cladding Rupture for High Burnup Fuel." The NRC staff has reviewed EPRI Report 3002028674/5, conducted a regulatory audit, and determined that additional information is required to complete the review.

Regulatory Basis The NRC staff is reviewing EPRI Report 3002028674/5 to ensure compliance with the requirements associated with the postulated loss-of-coolant accident (LOCA), including Title 10 of the Code of Federal Regulations (CFR) Section 50.46 and General Design Criteria 35 of Part 50, Domestic licensing of production and utilization facilities, Appendix A, General Design Criteria for Nuclear Power Plants. The purpose of EPRI Report 3002028674/5 is to develop bounding composite PWR plant models to demonstrate acceptable performance with respect to LOCA-induced FFRD for high burnup fuel rods susceptible to fine fragmentation. Assuring acceptable margin to cladding rupture for high burnup fuel is a means of demonstrating compliance with existing requirements for the LOCA, including the requirement in 10 CFR 50.46(b)(4) to maintain a coolable geometry.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 3

OFFICIAL USE ONLY - PROPRIETARY INFORMATION

a. Justification that only high-ranked phenomena are necessary to build a bounding composite model for each plant class.

b. A description of the methodology used to build the base composite model for each plant class before any modifications are made to accommodate high-ranked phenomena.

c. The treatment of plant geometric and operating parameters associated with medium and low-ranked phenomena that are not already addressed by the treatment associated with high-ranked phenomena.

d. EPRI Report 3002028674/5 does not propose a ((

)), as it relates to the cold leg/safety injection process for the IBLOCA safety injection phase. This parameter should have some ((

)) in the composite models according to the proposed methodology, but is not addressed in the TR.