ML25100A045
| ML25100A045 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/10/2025 |
| From: | Scott Wall Plant Licensing Branch III |
| To: | Rhoades D Constellation Energy Generation |
| Wall, S | |
| References | |
| EPID L-2024-LLA-0072 | |
| Download: ML25100A045 (1) | |
Text
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION April 10, 2025 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 - REQUEST FOR ADDITIONAL INFORMATION IN SUPPORT OF REVIEW OF LICENSE AMENDMENT REQUEST TO TRANSITION TO FRAMATOME GAIA FUEL (EPID L-2024-LLA-0072)
Dear David Rhoades:
By letter dated May 28, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24149A126), 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.
The NRC staff has reviewed the submittal and determined that additional information is needed to complete its review. The specific question is found in the enclosed request for additional information (RAI). On April 9, 2025, the CEG staff indicated that a response to the RAIs would be provided by May 9, 2025.
to this letter contains Proprietary information. When separated from Enclosure 1, this document is DECONTROLLED.
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION If you have any questions, please contact me by telephone at 301-415-2855 or via email 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 50-456 and STN 50-457 STN 50-454 and STN 50-455
Enclosures:
- 1. Request for Additional Information (Proprietary)
- 2. Request for Additional Information (Non-Proprietary) cc: Listserv
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION ENCLOSURE 2 REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TRANSITION TO FRAMATOME GAIA FUEL CONSTELLATION ENERGY GENERATION, LLC.
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 DOCKET NOS. STN 50-454, STN 50-455, STN 50-456, AND STN 50-457 (NON-PROPRIETARY)
Proprietary information pursuant to Section 2.390 of Title 10 of the Code of Federal Regulations has been redacted from this document.
Redacted Proprietary information is identified by empty double brackets.
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TRANSITION TO FRAMATOME GAIA FUEL CONSTELLATION ENERGY GENERATION, LLC.
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 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) 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 determined that the following information is needed to complete its review.
Nuclear Methods and & Fuel Analysis Branch (SFNB) Questions Regulatory Basis Appendix A to Title 10 of the Code of Federal Regulations, Part 50 (10 CFR 50), General Design Criterion (GDC) 10, Reactor Design, requires that the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to ensure that Specified Acceptable Fuel Design Limits (SAFDLs) are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences. The NRC reviews and approves analysis methods to ensure that they provide a realistic or conservative result, such as determining margin to SAFDLs, and that they adhere to applicable regulatory requirements. These methods frequently contain Limitations and Conditions that a licensee must demonstrate adherence to in order to have assurance realistic or conservative results are obtained.
SFNB-RAI-1 In audit meetings that took place from 2/24/2025 to 3/21/2025, the NRC staff discussed with the licensee several points regarding the method of adherence to ARITA Limitation and Condition 6, which requires, in the absence of pertinent plant-specific data or information, licensees [
]
With regard to this Limitation and Condition and the discussions that took place, please confirm the NRC staffs understanding of the following items:
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION For the GAIA fuel transition, the [
]
In response to this, [
]
The relevant [
] was not significant.
SFNB-RAI-2 The justification provided in ANP-4087, Revision 1, regarding adherence to ARITA Limitation and Condition 8 discusses the [
] with respect to the coupled and static evaluation model variants.
However, regarding the zero-dimensional evaluation model variant, [
] In audit meetings that took place from 2/24/2025 to 3/21/2025, the NRC staff discussed with the licensee several points regarding the method of adherence to Limitation and Condition 8.
Please confirm the NRC staffs understanding of the following items:
For the GAIA fuel transition does, [
]
For future analyses that [
]
SFNB-RAI-3 The justification provided in ANP-4087, Revision 1, regarding adherence to ARITA Limitation and Condition 9 discusses how [
]
Please provide a brief discussion of the analysis that was performed for the GAIA fuel transition LAR for demonstrating adherence to this Limitation and Condition. In this discussion, please include the magnitudes of [
]
SFNB-RAI-4 The justification provided in ANP-4087, Revision 1, regarding adherence to ARITA Limitation and Condition 11 discusses [
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION
]
This same comparison was provided in the ARITA topical report, ANP-10339P-A. While the results provided ANP-10339P-A demonstrate [
] which is conservative for a main steam line break event, the NRC staff has concerns with regard to the scaling applicability of the test facility to full-size [
] and the assurance that [
] will be conservatively predicted in future analyses for all relevant reactor designs. In particular, the scaling analysis report for the test facility indicates there are differences in the design of the [
]
In light of this, please provide a discussion on the scaling applicability of the [
] for the main steam line break event. In particular, please discuss [
]
SFNB-RAI-5 The justifications provided in ANP-4087, Revision 1, regarding adherence to ARITA Limitation and Conditions 12 and 13 discuss the establishment of [
] In audit meetings that took place from 2/24/2025 to 3/21/2025, Framatome indicated that [
]
Please provide a brief description of the generation of [
] the applicable lower pressure range, and the mean, standard deviation, and type of distribution.
Additionally, please [
]
SFNB-RAI-6 The justification provided in ANP-4087, Revision 1, regarding adherence to ARITA Limitation and Condition 15 discusses how justification will be established for the [
] for any event that exhibits a prompt critical
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION response. Please indicate the events that have been identified for the GAIA fuel transition LAR to exhibit a prompt critical response and provide a brief discussion of the analysis approach that was performed for these events. In this discussion, please include the magnitudes of [
] and identify the impact on pertinent figures of merit.
SFNB-RAI-7 In audit meetings that took place from 2/24/2025 to 3/21/2025, the NRC staff noted several items regarding the basis for item 7 under Section 2.1.2, Methodology Departures of ANP-4087P. Please confirm the following items regarding Methodology Departure Item 7, which discusses evaluating [
]
[
]
The evaluation demonstrated that, [
]
SFNB-RAI-8 (Audit Question 87)
Regarding Methodology Clarification 1a for ARITA in Section 2.1.3 of ANP-4087P, Revision 1, the charging and letdown system modeling, please further discuss [
]