RS-25-123, Supplement Related to License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, to Transition to Framatome Gaia Fuel and Exemptions to 10 CFR 50.46
| ML25225A150 | |
| Person / Time | |
|---|---|
| Site: | Braidwood, Byron  |
| Issue date: | 08/06/2025 |
| From: | Steinman R Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML25225A165 | List: |
| References | |
| RS-25-123, CAW-25-041 | |
| Download: ML25225A150 (1) | |
Text
4300 Winfield Road Warrenville, IL 60555 630 657 2000 Office RS-25-123 10 CFR 50.90 August 6, 2025 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and 50-457 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and 50-455
Subject:
Supplement Related to License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, to Transition to Framatome GAIA Fuel and Exemptions to 10 CFR 50.46
References:
- 1. CEG Letter RS-24-044, "License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, to transition to Framatome GAIA fuel and exemptions to 10 CFR 50.46 and 10 CFR 50 Appendix K," Dated May 28, 2024 (ADAMS Accession No. ML24149A125)
- 2. CEG Letter RS-25-088, Response to Request for Additional Information Related to License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, to Transition to Framatome GAIA Fuel and Exemptions to 10 CFR 50.46, Dated April 21, 2025 (ADAMS Accession No. ML25111A258)
Constellation Energy Generation, LLC (CEG) is submitting this supplement related to License Amendment Request (LAR) to transition to Framatome GAIA fuel at Braidwood Station, Units 1 and 2 (Braidwood), and Byron Station, Units 1 and 2 (Byron). This supplement provides updated information regarding the proposed revision of the Technical Specifications (TS) to allow the use of Framatome GAIA fuel at Braidwood and Byron in Reference 1 and the response to request for additional information (RAI) in Reference 2.
During the Braidwood 2025 NRC Comprehensive Engineering Team Inspection (CETI),
engineering identified an issue related to the emergency core cooling system (ECCS) recirculation phase of a loss of coolant accident (LOCA). The issue is related to the scenario when one (1) component cooling (CC) pump supplies cooling water to the residual heat removal (RHR) heat exchanger, and the flow path to the non-essential CC loads (spent fuel pool cooling Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure
August 6, 2025 U.S. Nuclear Regulatory Commission Page 2 heat exchanger, letdown heat exchanger, reactor coolant pumps, waste gas compressor, radwaste evaporators) is not isolated. In this line-up, the CC flow to the RHR heat exchanger is below the required value of 5,000 gpm (controlled by site procedures) that is credited in the containment integrity analysis.
Westinghouse has performed a sensitivity analysis using the model from the containment analysis of record. The sensitivity analysis determined the impact of the lower CC flow to the RHR heat exchanger for the entire duration of the ECCS recirculation phase. The results of the analysis summarized in Table 1 show small increases in the containment temperature, pressure and sump water temperature in the ECCS recirculation phase following a LOCA.
Table 1 - ECCS Recirculation Phase Parameters Increase Parameter Unit 1 Unit 2 Containment Steam Temperature (°F) 0.14 0.13 Containment Pressure (psi) 0.32 0.26 Sump Water Temperature (°F) 0.23 0.15 The lower CC flow does not have any impact on the post-LOCA maximum calculated containment temperature and pressure values because the peak values occur during the ECCS injection phase.
The containment temperature and pressure during the ECCS recirculation phase remain below the peak values calculated during the ECCS injection phase. There is a small increase in the recirculation sump water temperature from what is reported in Table 3.5.3-1 of the LAR (Reference 1). This small increase does not have an adverse impact on the RHR and containment spray pumps taking suction from the recirculation sump.
The results of the Westinghouse sensitivity analysis will be documented in a formal revision to the containment integrity analysis of record.
On April 21, 2025, CEG responded to a RAI related to the LAR to transition Braidwood and Byron to Framatome GAIA fuel as documented in Reference 2.
CEG responded to question SNSB-RAI-1 by providing the numerical power peaking factor (F+)
to be used on VANTAGE+ fuel during the transition cycles to GAIA fuel at Byron and Braidwood. CEG is notifying the NRC that recent calculation refinements have identified a revision to the second transition cycle F+ penalty previously provided. In updating the F+
penalty, it was further identified the corresponding Core Operating Limits Report (COLR) limits were incorrect. For the second transition cycle, the [
]a,c previously reported. The first transition cycle's penalty corresponds to a Westinghouse [
]a,c, and the second transition cycle's [
]a,c corresponds to an [
]a,c. All other aspects of the original CEG response to SNSB-RAI-1 remain valid. The F+ penalty value utilized in the core design will be provided as part of the Core Operating Limits Report.
Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure
August 6, 2025 U.S. Nuclear Regulatory Commission Page 3 CEG also provided rod control system speed control speed limits in response to SNSB-RAI-3.
CEG would like to clarify the previous response. Specifically, Framatome evaluations consider and evaluate both rod withdrawal and insertion speeds up to 72 steps per minute. Although the Framatome evaluations consider withdrawal speed up to 72 steps per minute, CEG is setting a rod withdrawal speed limit of 8 steps per minute. All other aspects of the original CEG response to SNSB-RAI-3 remain valid.
CEG has reviewed the information supporting the finding of no significant hazards consideration and the environmental consideration that were previously provided to the NRC in Reference 1.
The revised information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"
paragraph (b), CEG is notifying the State of Illinois of this supplement to the application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.
There are no regulatory commitments contained in this letter. Should you have any questions concerning this letter, please contact Brian Seawright at (779) 231-6151.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 6th day of August 2025.
Respectfully, Rebecca L. Steinman Senior Manager - Licensing Constellation Energy Generation, LLC
Attachment:
NRR Project Manager - Braidwood / Byron NRC Regional Administrator, Region III NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station Illinois Emergency Management Agency - Division of Nuclear Safety
- Steinman, Rebecca Lee Digitally signed by Steinman, Rebecca Lee Date: 2025.08.06 07:55:32 -05'00' Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure Non-Proprietary Version - Proprietary Information Withheld from Public Disclosure
ATTACHMENT Affidavit Westinghouse
Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-041 Page 1 of 3 Commonwealth of Pennsylvania:
County of Butler:
(1)
I, Jerrod Ewing, Manager, Operating Plants Licensing; Cranberry Township, PA, have been specifically delegated and authorized to apply for withholding and execute this Affidavit on behalf of Westinghouse Electric Company LLC (Westinghouse).
(2)
I am requesting the proprietary portions of RS-25-123, Revision 0 be withheld from public disclosure under 10 CFR 2.390.
(3)
I have personal knowledge of the criteria and procedures utilized by Westinghouse in designating information as a trade secret, privileged, or as confidential commercial or financial information.
(4)
Pursuant to 10 CFR 2.390, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld.
(i)
The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse and is not customarily disclosed to the public.
(ii)
The information sought to be withheld is being transmitted to the Commission in confidence and, to Westinghouses knowledge, is not available in public sources.
(iii)
Westinghouse notes that a showing of substantial harm is no longer an applicable criterion for analyzing whether a document should be withheld from public disclosure. Nevertheless, public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar technical evaluation justifications and licensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.
- This record was final approved on 08/05/2025 14:01:58. (This statement was added by the PRIME system upon its validation)
Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-041 Page 2 of 3 (5)
Westinghouse has policies in place to identify proprietary information. Under that system, information is held in confidence if it falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:
(a)
The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.
(b)
It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage (e.g., by optimization or improved marketability).
(c)
Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.
(d)
It reveals cost or price information, production capacities, budget levels, or commercial strategies of Westinghouse, its customers or suppliers.
(e)
It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs of potential commercial value to Westinghouse.
(f)
It contains patentable ideas, for which patent protection may be desirable.
(6)
The attached documents are bracketed and marked to indicate the bases for withholding. The justification for withholding is indicated in both versions by means of lower-case letters (a) through (f) located as a superscript immediately following the brackets enclosing each item of information being identified as proprietary or in the margin opposite such information. These lower-case letters refer to the types of information Westinghouse customarily holds in confidence identified in Sections (5)(a) through (f) of this Affidavit.
- This record was final approved on 08/05/2025 14:01:58. (This statement was added by the PRIME system upon its validation)
Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-041 Page 3 of 3 I declare that the averments of fact set forth in this Affidavit are true and correct to the best of my knowledge, information, and belief. I declare under penalty of perjury that the foregoing is true and correct.
Executed on: 8/4/2025 Signed electronically by Jerrod Ewing
- This record was final approved on 08/05/2025 14:01:58. (This statement was added by the PRIME system upon its validation)