ML25112A226
| ML25112A226 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/30/2025 |
| From: | Scott Wall Plant Licensing Branch III |
| To: | |
| Wall, S | |
| References | |
| EPID L-2025-LRM-0019 | |
| Download: ML25112A226 (4) | |
Text
April 30, 2025 LICENSEE:
Constellation Energy Generation, LLC FACILITIES: Braidwood Station, Units 1 and 2; and Byron Station, Unit Nos. 1 and 2
SUBJECT:
SUMMARY
OF APRIL 3, 2025, MEETING WITH CONSTELLATION ENERGY GENERATION, LLC REGARDING APPLICABILITY OF GENERIC LETTER 83-11 (EPID L-2025-LRM-0019)
On April 3, 2025, an observation meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Constellation Energy Generation, LLC (CEG, the licensee) via webinar. The purpose of this meeting was for CEG to discuss the applicability of Generic Letter (GL) 83-11, Licensee Qualification for Performing Safety Analyses in Support of Licensing Actions, at Braidwood Station, Units 1 and 2 (Braidwood), and Byron Station, Units 1 and 2 (Byron). The meeting notice and agenda dated January 2, 2025, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML25090A056, and CEGs meeting handout is available at ML25087A197. A list of attendees is enclosed.
The licensee indicated that as part of the Braidwood and Byron transition away from Westinghouses Best Estimate Analyzer for Core Operations Nuclear (BEACON) Power Distribution Monitoring System core monitoring system, the licensee plans to use the Studsviks GARDEL core monitoring system. The underlying code for the GARDEL system is the SIMULATE5 code from the Studsvik Generic pressurized water reactor (PWR) topical (ML17236A419). GARDEL will be used to monitor and surveille Core Operating Limits Report (COLR) parameters like peaking factors but does not alter any COLR items. For the transitions, cores containing both Westinghouse and Framatome fuel, the licensee will continue to use the Westinghouse safety analysis methodologies. Once the licensee is using only Framatome fuel, they will transition to using Framatome methods as described in fuel transition license amendment request (ML24352A075).
The licensee indicated that during the transition core phase of the project, the CEG fuel group will need to use SIMULATE5 to perform comparison calculations to validate that the calculated measurement uncertainty parameters of GARDEL remain below the current COLR defined measurement uncertainty values used in the Westinghouse fuel safety evaluation. This way, Byron and Braidwood do not need to alter any of uncertainties parameters used as inputs to their Safety Evaluations methods in Technical Specification (TS) 5.6.5.b.
The licensee indicated that there have been discussions that using SIMULATE5s measurement uncertainties to perform this validation even though the licensee will continue to use the measurement uncertainties defined by the Westinghouse methods to support the sites safety evaluations falls into the scope of GL 83-11. Since SIMULATE5 has been reviewed and approved by the NRC (Studsvik Generic PWR Topical) but is not currently part of TS 5.6.5.b (because it is not used for the Safety Evaluation itself), the licensee is unclear if this proposed usage falls within the scope of GL 83-11. For additional details on the licensees presentation, please refer to the CEGs meeting handout referenced.
The NRC staff provided feedback on the following topic:
Potential need to update lists of methods:
The staff asked if any new methods will be added to the list of methods in the COLR.
The staff asked if output from SIMULATE5 will be used to calculate COLR limits or used to confirm that parameters remain within COLR limits. The staff stated that it is not clear that GL 83-11 can, by itself, justify not adding a new method to the COLR because GL 83-11 was created prior to the concept of a COLR (GL 88-16). The staff stated that a clear, detailed justification for not needing to add any new methods to the COLR would aid the staff in assessing the application of GL 83-11 to the licensees intended purpose.
No members of the public had questions during the meeting. No regulatory decisions were made at this meeting. Please direct any inquiries to me at 301-415-2855, or 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 50-456, STN 50-457, STN 50-454 and STN 50-455
Enclosure:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES APRIL 3, 2025, PUBLIC MEETING WITH CONSTELLATION ENERGY GENERATION, LLC REGARDING APPLICABILITY OF GENERIC LETTER 83-11 Name Organization Scott Wall U.S. Nuclear Regulatory Commission (NRC)
Ilka Berrios NRC David Garmon NRC Jeremy Dean NRC Ahsan Sallman NRC Matthew Hamm NRC Brian Seawright Constellation Energy Generation, LLC (CEG)
Rebecca Steinman CEG Lisa Zurawski CEG Rosanne Carmean CEG Neil Huizenga CEG Nicholas Domenico CEG Efaz Haque CEG John Massari CEG Kanaga Sahadewan CEG Boyan Ivanov CEG Jason Ruzic CEG Phil Sharpe N/A Stephen O'Hearn Dominion Energy Mary Miller Dominion Energy
ML25112A226 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DORL/LPL3/BC NRR/DORL/LPL3/PM NAME SWall SRohrer IBerrios SWall DATE 04/22/2025 04/24/2025 04/30/2025 04/30/2025