ML25125A263
| ML25125A263 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 05/16/2025 |
| From: | Scott Wall NRC/NRR/DORL/LPL3 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Wall, S | |
| References | |
| EPID L-2024-LLA-0072 | |
| Download: ML25125A263 (1) | |
Text
May 16, 2025 Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 - AUDIT
SUMMARY
FOR LICENSE AMENDMENT REQUEST TO TRANSITION TO FRAMATOME GAIA FUEL (EPID L-2024-LLA-0072)
Dear Mr. Rhoades:
By letter dated May 28, 2024 (Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML24149A125), Constellation Energy Generation, LLC (Constellation, the licensee), submitted a license amendment request (LAR) for Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2, to the U.S. Nuclear Regulatory Commission (NRC). Specifically, the proposed LAR would make several technical specification changes to allow transition to Framatome GAIA fuel.
To support its review, by letter dated November 25, 2024 (ML24299A255), the NRC staff notified the licensee that they would conduct a regulatory audit through an online portal (also known as electronic portal, ePortal, electronic reading room) established by the licensee. The regulatory audit summary is enclosed with this letter.
If you have any questions, please contact me at (301) 415-2855, or by e-mail at Scott.Wall@nrc.gov.
Sincerely,
/RA/
Scott P. Wall, Senior Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454, STN 50-455, STN 50-456, and STN 50-457
Enclosure:
Regulatory Audit Summary cc: Listserv
Enclosure REGULATORY AUDIT
SUMMARY
REGARDING LICENSE AMENDMENT REQUEST TO TRANSITION TO FRAMATOME GAIA FUEL BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 CONSTELLATION ENERGY GENERATION, LLC.
DOCKET NOS. STN 50-454, STN 50-455, STN 50-456, AND STN 50-457
1.0 BACKGROUND
By application dated May 28, 2024 (Agencywide Documents Access and Management System(ADAMS) Package Accession No. ML24149A125), Constellation Energy Generation, LLC (CEG, the licensee) submitted a license amendment request (LAR) for Braidwood Station, Units 1 and 2 (Braidwood), and Byron Station, Units 1 and 2 (Byron). The proposed amendments would revise technical specifications to allow the use of Framatome GAIA fuel at Braidwood and Byron.
The U.S. Nuclear Regulatory Commission (NRC) staff performed a preliminary review of the LAR and determined that a regulatory audit would assist in the timely completion of the review.
An audit plan was provided to the licensee on November 25, 2024 (ML24299A255), which provided the list of requested documents and other details pertaining to the audit. The purpose of the audit was to gain an understanding of the information needed to support the NRC staffs licensing decision regarding the LAR and to develop requests for additional information (RAIs),
if necessary. The information submitted in support of the LAR is under final review, and any additional information needed to support the LAR review will be formally requested by the NRC staff using the RAI process in accordance with Office of Nuclear Reactor Regulation (NRR)
Office Instruction LIC-101, Revision 6, License Amendment Review Procedures (ML19248C539).
The regulatory audit is a planned license or regulation-related activity that includes the examination and evaluation of primarily non-docketed information. The regulatory audit is conducted with the intent to gain understanding, to verify information, and/or to identify information, that will require docketing to support the basis of a licensing or regulatory decision.
Performing a regulatory audit of the licensees information is expected to assist the NRC staff in efficiently conducting its review or gain insights on the licensees processes or procedures.
Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. However, the NRC staff may review supporting information retained as records under Title 10 of the Code of Federal Regulations (10 CFR) section 50.71, Maintenance of records, making of reports, and/or 10 CFR 54.37, Additional records and recordkeeping requirements, which, although not required to be submitted as part of the licensing action,
would help the NRC staff better understand the licensees submitted information.
2.0 SCOPE By letter dated November 25, 2024, the NRC staff issued an audit plan. To support discussions, the NRC staff provided audit questions with items for CEG to clarify. CEG posted answers to these questions to the online portal. The NRC staff held clarification discussions with the CEG staff via Microsoft Teams. All audit questions were discussed. Technical discussions were focused on information supporting the licensees request to transition to Framatome GAIA fuel at Braidwood and Byron.
3.0 AUDIT TEAM The NRC audit team included the following:
Joel Wiebe, Plant Licensing Branch III (LPL3)
Scott Wall, LPL3 Jo Ambrosini, Nuclear Systems Performance Branch (SNSB)
Robert Beaton, SNSB Jack Vande Polder, SNSB Charley Peabody, SNSB Logan Gaul, Nuclear Methods and & Fuel Analysis Branch (SFNB)
Kevin Heller, SFNB John Lehning, SFNB Richard Fu, SFNB Matthew Hamm, Technical Specifications Branch (STSB)
Ravi Grover, STSB David Nold, Containment and Plant Systems Branch (SCPB)
Hanry Wagage, SCPB Sean Meighan, Radiation Protection and Consequence Branch (ARCB)
Mike Mazaika, External Hazards Branch (EXHB) 4.0 DOCUMENT AND FILES REVIEWED The NRC staff reviewed the following documents:
Exelon Analysis No. CN-LIS-01-155, Revision 0, Byron / Braidwood Units 1 and 2 Hot Leg Switchover and Long-Term Core Cooling (LTCC), September 30, 2024.
Framatome Calculation FS10068721, Revision 1.0, Byron/Braidwood Fuel Transition -
Turbine Trip ARITA Analysis, April 16, 2024.
Framatome Calculation FS10068728, Revision 1.0, Braidwood/Byron Uncontrolled Bank Withdrawal at Power, April 18, 2024.
Framatome Calculation FS10027800, Revision 4.0, Rod Worth Uncertainties for ARITA, October 1, 2024.
Framatome Calculation FS10028795, Revision 5.0, ARITA Peaking Sampling Uncertainty, October 2, 2024.
Framatome Calculation FS10048992, Revision 1.0, Subscale Head Loss Test Program Report - GAIA (for US Market), March 20, 2020.
Framatome Calculation FS10063842, Revision 3.0, Byron-Braidwood GAIA Transition Core Analysis, July 22, 2024.
Framatome Calculation FS10064620, Revision 1.0, Byron / Braidwood Unit 1 Cycle 26 RLBLOCA Uncertainty Analysis, February 2, 2024.
Framatome Calculation FS10064625, Revision 1.0, Byron / Braidwood Unit 1 Transient Analysis for SBLOCA, February 9, 2024.
Framatome Calculation FS10064966, Revision 3.0, Byron and Braidwood Units 1 and 2 Analytical Input Summary of Generic Input Parameters for ARITA, December 14, 2023.
Framatome Calculation FS10064966, Revision 6.0, Byron and Braidwood Units 1 and 2 Analytical Input Summary of Generic Input Parameters for ARITA, October 9, 2024.
Framatome Calculation FS10065505, Revision 3.0, Byron/Braidwood GAIA Fuel Transition - UFSAR 15.1 Non-LOCA Analytical Input Summary, August 13, 2024.
Framatome Calculation FS10065826, Revision 2.0, Byron/Braidwood GAIA Fuel Transition - UFSAR 15.6 Non-LOCA Analytical Input Summary, February 22, 2024.
Framatome Calculation FS10065952, Revision 2.0, Byron/Braidwood GAIA Fuel Transition - UFSAR 15.3 Non-LOCA Analytical Input Summary, February 22, 2024.
Framatome Calculation FS10066067, Revision 6.0, Byron/Braidwood GAIA Fuel Transition - UFSAR 15.4 Non-LOCA Analytical Input Summary, October 10, 2024.
Framatome Calculation FS10066539, Revision 3.0, Byron/Braidwood GAIA Fuel Transition - UFSAR 15.2 Non-LOCA Analytical Input Summary, June 13, 2024.
Framatome Calculation FS10067349, Revision 2.0, Byron and Braidwood: AREA Range of Key Parameters, April 16, 2024.
Framatome Calculation FS10068715, Revision 1.0, Byron/Braidwood Fuel Transition -
FSAR 15.1.2 - Increase in Feedwater Flow, October 17, 2024.
Framatome Calculation FS10068716, Revision 1.0, Byron/Braidwood Fuel Transition -
Excessive Increase in Secondary Steam Flow ARITA Analysis, April 16, 2024.
Framatome Calculation FS10068717, Revision 1.0, Byron/Braidwood Fuel Transition -
Post-Scram Steam System Piping Failure with Offsite Power Available ARITA Analysis, September 30, 2024.
Framatome Calculation FS10068725, Revision 1.0, Byron/Braidwood Fuel Transition -
Reactor Coolant Pump Shaft Seizure (Locked Rotor) ARITA Analysis, April 16, 2024.
Framatome Calculation FS10068728, Revision 2.0, Braidwood/Byron Uncontrolled Bank Withdrawal at Power, October 25, 2024.
Framatome Calculation FS10068729, Revision 1.0, Byron/Braidwood Fuel Transition -
Dropped RCCA/Dropped RCCA Bank, October 11, 2024.
Framatome Calculation FS10068734, Revision 1.0, Byron/Braidwood Fuel Transition -
Inadvertent Opening of a Pressurizer Safety or Relief Valve ARITA Analysis, April 17, 2024.
Framatome Calculation FS10068743, Revision 1.0, Byron/Braidwood Fuel Transition -
FSAR 15.1.2 - Increase in Feedwater Flow - Mode 1 FCM/TCS, October 30, 2024.
Framatome Calculation FS10070187, Revision 2.0, ARITA - Limitation and Condition #13 - Boiler Region Void Uncertainty at Lower Pressures - FRIGG-2, FRIGG-3, KATHY, and RBHT Benchmarks, April 9, 2024.
Framatome Calculation FS10070253, Revision 3.0, Byron and Braidwood Non-LOCA Summary Report with ARITA Methodology, May 10, 2024.
Framatome Calculation FS10070806, Revision 2.0, ARITA MB-2 MSLB Benchmark, March 26, 2024.
Framatome Calculation FS10070957, Revision 1.0, Byron/Braidwood Fuel Transition -
FSAR 15.1.2 - Increase in Feedwater Flow Mode 2, November 16, 2024.
Framatome Calculation FS10071068, Revision 1.0, ARITA-Limitation and Condition #18 - Comparison to Measured and Predicted Data, April 4, 2024.
Framatome Calculation FS10074274, Revision 1.0, Byron Unit 1 LPFA [Lower Plenum Flow Anomaly] DNB Penalty Analysis, November 1, 2024.
Framatome Licensing Report ANP4115P, Revision 0, Byron/Braidwood Unit 2 Small Break LOCA Analysis, November 2024.
Framatome Licensing Report ANP4116P, Revision 0, Byron/Braidwood Unit 2 Large Break LOCA Analysis, November 2024.
TS Bases Change Packages for the following TS o
2.1.1, Reactor Core SLs [Safety Limits]
o 3.2.1, Heat Flux Hot Channel Factor (FQ(Z))
o 3.2.3, Axial Flux Difference (AFD) o 3.5.1, Accumulators o
3.5.4, Refueling Water Storage Tank (RWST)
Westinghouse document WCAP-16676-NP, Analysis Update for the Inadvertent Loading Event, March 2009.
Westinghouse Document, CE-24-252, Attachment 1, Byron and Braidwood DNB Mixed Core Analysis Report, August 20, 2024.
In addition to the documents listed above, the licensee response to the various audit questions was also included on the portal for NRC staff review.
5.0 RESULTS OF THE AUDIT As a result of the audit, the NRC staff gained a better understanding of the licensees analyses and calculations that provide the technical support for the LAR. Several RAIs were issued to the licensee on March 26, 2025 (ML25085A297), and April 10, 2025 (ML25100A045). The licensee provided a response to the RAIs on April 21, 2025 (ML25111A257), and May 1, 2025 (ML25121A230).
ML25125A263 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DSS/SNFB/BC NAME SWall SLent SKrepel DATE 05/05/2025 5/6/25 05/06/2025 OFFICE NRR/DSS/SCPB/BC NRR/DSS/STSB/BC NRR/DRA/ARCB NAME MValentin SMehta KHsueh DATE 05/06/2025 05/06/2025 05/16/2025 OFFICE NRR/DSS/SNSB NRR/DEX/EXHB/BC NRR/DORL/LPL3/BC(A)
NAME DMurdock BHayes IBerrios 05/06/2025 05/15/2025 05/16/2025 OFFICE NRR/DORL/LPL3/PM NAME SWall DATE 05/16/2025