ML25318B208
| ML25318B208 | |
| Person / Time | |
|---|---|
| Site: | Braidwood, Byron  |
| Issue date: | 11/12/2025 |
| From: | Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML25318B206 | List: |
| References | |
| RS-25-152 | |
| Download: ML25318B208 (1) | |
Text
Attachment 2 Evaluation of Proposed Changes (Non-Proprietary)
Page 1 of 7
Subject:
License Amendment Request for Proposed Change to Limitations and Conditions on Non-LOCA Transient/Accident Methodology 1.0
SUMMARY
DESCRIPTION 2.0 DETAILED DESCRIPTION
3.0 TECHNICAL EVALUATION
4.0 REGULATORY EVALUATION
5.0 ENVIRONMENTAL CONSIDERATION 6.0 REFERENCES Evaluation of Proposed Changes (Non-Proprietary)
Page 2 of 7 1.0
SUMMARY
DESCRIPTION In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit or early site permit," and 10 CFR 50.59, "Changes, tests, and experiments," Constellation Energy Generation, LLC, (CEG) requests approval for a change to the Limitations and Conditions (L&C) #3, and #10 from the U.S. Nuclear Regulatory Commission's (NRC) Safety Evaluation Table 3.7.3 (Reference 3). The proposed change is applicable to Renewed Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2 (Braidwood) and Renewed Facility Operating License Nos. NPF-37 and NPF-66 for Byron Station, Units 1 and 2 (Byron).
The proposed change requests NRC approval to update ((
)) that was used and approved for Braidwood and Byron transition to GAIA fuel (Reference 3).
Specifically, to modify the L&C #10 ((
)) The proposed change to L&C #10 would ((
)) in all applicable safety analyses.
Additionally, this application proposes to revise the ARITA methodology to ((
)) The proposed change is to provide ((
))
2.0 DETAILED DESCRIPTION CEG is proposing to revise and update two L&C associated with the approved Non-LOCA Transient/Accident Methodology described in Reference 3. Specifically, CEG is proposing changes to L&C #10 regarding the sampling range ((
)) and to L&C #3 regarding Byron and Braidwood key parameter sampling strategy.
2.1 Sampling Range for ((
))
Historically, ((
))
In previously approved license amendments for Byron and Braidwood (Reference 3), ((
))
Evaluation of Proposed Changes (Non-Proprietary)
Page 3 of 7 The proposed change fixes ((
)) in ARITA-based analyses ((
)) This proposed change applies to all transients evaluated using the ARITA methodology ((
)) including those supporting Departure from Nucleate Boiling (DNB), Fuel Centerline Melt (FCM), and Transient Cladding Strain (TCS) evaluations. ((
))
2.2 Key Parameter Sampling Strategy The proposed changes are to provide an alternative method for ((
)) The alternative method is consistent with L&C #3 of Reference 1 and the approach described in Section 2.1.4 of Reference 2, with the following modifications:
- 1. ((
))
- 2. ((
))
The definition of key and non-key parameters are consistent with Section 2.1.4 of Reference 2.
This proposed changes only focus on how the ranges are selected. These changes represent a departure from the previous approach, ((
)) Analyses which ((
)) using the previously approved methods remains valid.
((
)) the ARITA methodology (Reference 1) and approved in Reference 3.
3.0 TECHNICAL EVALUATION
3.1 Sampling Range for ((
))
The impact ((
)) ARITA-based transient analyses was determined by assessing its influence on three key figures of merit: DNB, FCM, and TCS. The analysis used results from previously completed simulations supporting the Byron and Braidwood fuel transition.
Evaluation of Proposed Changes (Non-Proprietary)
Page 4 of 7
((
))
((
))
Across all three figures of merit, ((
)) do not significantly influence the calculated safety margins:
((
))
((
)) these did not correspond to any observable impact on margin behavior.
These findings support the conclusion ((
)) does not enhance the accuracy or conservatism of ARITA-based safety analyses.
Therefore, it is technically justified ((
)) This change simplifies the analysis process while maintaining alignment with the approved methodology.
3.2 Key Parameter Sampling Strategy The proposed changes clarify the existing process while continuing to meet L&C #3 of Reference 1 and the approach previously approved in Reference 3. The structured approach
((
)) while maintaining flexibility for future methodological improvements.
The proposed changes maintain the key characteristics of the ARITA methodology as presented within Reference 2 while ((
)) It does not alter the acceptance criteria, analytical methods, or conclusions of the safety analyses previously submitted and approved as the alternative method is consistent with L&C #3 of Reference 1.
Evaluation of Proposed Changes (Non-Proprietary)
Page 5 of 7
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements / Criteria The following applicable regulations and regulatory requirements were reviewed in development of this submittal:
10 CFR 50, Appendix A, " General Design Criteria for Nuclear Power Plants," Criterion 10, "Reactor design," requires that the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.
10 CFR 50.36, "Technical specifications." In accordance with 10 CFR 50.36, TS are required to include (1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls. The Core Operating Limits Report (COLR) is part of the administrative controls which is included in Braidwood and Byron TS in accordance with 10 CFR 50.36.
4.2 Precedents Byron Amendment 240 and Braidwood Amendment 242 (Reference 3) has imposed L&C that have differed from the L&C associated with ANP-10339P-A (Reference 1). Specifically, L&C #10 from Reference 3 was a change from ANP-10339P-A parameter SEC-2b.
4.3 No Significant Hazards Consideration In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit or early site permit," and 10 CFR 50.59, "Changes, tests, and experiments," Constellation Energy Generation, LLC, (CEG) requests approval for a change to Limitations and Conditions (L&C) in Amendments 242 to Renewed Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2 and in Amendments 240 to Renewed Facility Operating License Nos. NPF-37 and NPF-66 for Byron Station, Units 1 and 2.
According to 10 CFR 50.92, "Issuance of amendment," paragraph (c), a proposed amendment to an operating license involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:
(1) Involve a significant increase in the probability or consequences of any accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
Evaluation of Proposed Changes (Non-Proprietary)
Page 6 of 7 CEG has evaluated the proposed changes, using the criteria in 10 CFR 50.92, and has determined that the proposed changes do not involve a significant hazards consideration. The following information is provided to support a finding of no significant hazards consideration.
- 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No.
The proposed changes impact a sampling range parameter and provide an alternative method for plant-specific implementation of the ARITA methodology at Byron and Braidwood. The change to the sampling range parameter does not enhance the accuracy or conservatism of the ARITA-based safety analysis, and the proposed alternative method does not alter the acceptance criteria, analytical methods or conclusions of the safety analyses. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Does the proposed change create the possibility of a new or different accident from any accident previously evaluated?
Response: No.
The proposed changes do not change the design, configuration, or method of operation of the plant. The proposed changes do not involve a physical alteration of the plant (i.e., no new or different kinds of equipment will be installed). There are no changes to the required limits set forth in Braidwood and Byron TS and the reactor will continue to be operated within its analyzed operating and design envelope.
Therefore, the proposed changes do not create the possibility of a new or different accident from any accident previously evaluated.
- 3. Does the proposed change involve a significant reduction in a margin of safety?
Response: No.
The margin of safety is established through equipment design, operating parameters, and the setpoints at which automatic actions are initiated. Approved methodologies will be used to ensure the plant continues to meet applicable design criteria and safety analysis acceptance criteria. The proposed changes have been analyzed and results in no significant influence on the calculated safety margins. There are no changes to the required limits set forth in Braidwood and Byron TS. The reactor will continue to be operated within its analyzed operating and design envelope.
Therefore, the proposed changes do not involve a significant reduction in a margin of safety.
Based on the above evaluation, CEG concludes that the proposed changes do not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of "no significant hazards consideration" is justified.
Evaluation of Proposed Changes (Non-Proprietary)
Page 7 of 7 4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
5.0 ENVIRONMENTAL CONSIDERATION CEG has evaluated the proposed amendment and has determined that the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
6.0 REFERENCES
- 1. ANP-10339P-A, Revision 0, ARITA - ARTEMIS/RELAP Integrated Transient Analysis Methodology Topical Report, October 2023 (ADAMS Accession No. ML24040A182).
- 2. ANP-4087P, Revision 2, Byron and Braidwood Non-LOCA Summary Report with ARITA Methodology, August 2025 (Attachment 17 to RS-24-044 in ADAMS Accession No. ML24149A125).
- 3. NRC Safety Evaluation Report, Braidwood Station, Units 1 and 2; and Byron Station, Units 1, and 2 - Issuance of Amendments to Revise Technical Specifications to use Framatome GAIA Fuel (EPID L-2024-LLA-0072), dated August 21, 2025 (ADAMS Accession No. ML25148A202).