NL-26-0045, Request to Revise Unit 3 Implementation Schedule for Amendment 203
| ML26037A257 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 02/06/2026 |
| From: | Coleman J Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-26-0045 | |
| Download: ML26037A257 (0) | |
Text
Regulatory Affairs 3535 Colonnade Parkway Birmingham, AL 35243 205 992 5000 February 6, 2026 Docket Nos.: 52-025 NL-26-0045 10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Southern Nuclear Operating Company Vogtle Electric Generating Plant - Unit 3 License Amendment Request:
Request to Revise Unit 3 Implementation Schedule for Amendment 203 Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC) requests an amendment to the Combined License (COL) for Vogtle Electric Generating Plant (VEGP) Unit 3 (License Number NPF-91) to delay the implementation of Amendment No. 203 for one refueling cycle for implementation prior to startup from the Fall 2027 refueling outage.
By letter dated February 14, 2025 (ADAMS Accession No. ML25045A166), as supplemented by letters dated March 31, July 9, and July 16, 2025 (ML25090A283, ML25190A653, and ML25197A672, respectively), SNC submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request (LAR) that proposed to revise Technical Specifications (TS) 3.3.8, Engineered Safeguards Actuation System Instrumentation, Table 3.3.8-1, to add a new Function 11.b, Reactor Coolant System (RCS) Cold Leg Temperature (Tcold) - High. NRC issued the amendment on August 8, 2025 (ML25199A048) with implementation required prior to startup from the Spring 2026 refueling outage.
The Enclosure to this letter provides the description, technical evaluation, regulatory evaluation (including the Significant Hazards Consideration), and environmental considerations for the proposed change.
This letter contains no regulatory commitments. This letter has been reviewed and determined not to contain security-related information.
SNC requests NRC staff review and approval of this LAR by May 4, 2026, shortly prior to the anticipated startup from the Spring 2026 refueling outage currently required for implementation.
SNC expects to implement the proposed amendment immediately upon issuance. The requested approval schedule will ensure NRC approval prior to startup from the Spring 2026 Unit 3 refueling outage (3R02).
U. S. Nuclear Regulatory Commission NL-26-0045 Page 2 In accordance with 10 CFR 50.91, SNC is notifying the State of Georgia by transmitting a copy of this letter and its enclosure to the designated State Official.
If you have any questions, please contact Ryan Joyce at (205) 992-6468.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 6th of February, 2026.
Respectfully submitted, Jamie M. Coleman Director, Regulatory Affairs Southern Nuclear Operating Company
Enclosure:
Evaluation of Proposed Changes cc:
NRC Regional Administrator, Region ll NRR Project Manager - Vogtle 3 & 4 Senior Resident Inspector - Vogtle 3 & 4 Director, Environmental Protection Division - State of Georgia Document Services RTYPE: VND.LI.L00 Digitally signed by JAMIEMCO Date: 2026.02.06 11:42:57
-06'00'
Enclosure to NL-26-0045 Evaluation of Proposed Changes
- 1.
SUMMARY
DESCRIPTION
- 2.
DETAILED DESCRIPTION 2.1 Current Requirement 2.2 Reason for Proposed Change 2.3 Description of Proposed Change
- 3.
TECHNICAL EVALUATION
- 4.
REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 Significant Hazards Consideration 4.4 Conclusions
- 5.
ENVIRONMENTAL CONSIDERATION
- 6.
REFERENCES
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-1
- 1.
SUMMARY
DESCRIPTION Southern Nuclear Operating Company (SNC) requests an amendment to the Combined License (COL) for Vogtle Electric Generating Plant (VEGP) Unit 3 to delay the implementation of Amendment No. 203 for one refueling cycle.
By letter dated February 14, 2025 (ADAMS Accession No. ML25045A166), as supplemented by letters dated March 31, July 9, and July 16, 2025 (ML25090A283, ML25190A653, and ML25197A672, respectively), SNC submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request (LAR) that proposed to revise Technical Specifications (TS) 3.3.8, Engineered Safeguards Actuation System Instrumentation, Table 3.3.8-1, to add a new Function 11.b, Reactor Coolant System (RCS)
Cold Leg Temperature (Tcold) - High. NRC issued the amendment on August 8, 2025 (ML25199A048) with implementation required prior to startup from the Spring 2026 refueling outage.
- 2. DETAILED DESCRIPTION 2.1 Current Requirement Unit 3 Amendment No. 203 was issued with implementation required prior to startup from the Spring 2026 refueling outage.
2.2 Reason for Proposed Change The design change involves revisions to Protection and Safety Monitoring System (PMS) software for the actuation of the passive residual heat removal heat exchanger (PRHR HX).
Westinghouse Electric Company (WEC) is performing the PMS software modifications in accordance with their NRC-approved 10 CFR 50 Appendix B program with SNC conducting WEC vendor oversight. Implementation of the rigorous processes required for PMS software changes outlined in the previous SNC submittals supporting the amendment, has experienced delays in WEC completion and delivery. These vendor delivery delays are impacting downstream efforts to produce SNC internal change control packages, work planning, and post modification testing development. Furthermore, Westinghouse scheduled delivery of the corresponding simulator software changes does not support the requisite training of the plant operators prior to startup from the Spring 2026 refueling outage.
The project team and management team have been making best efforts to mitigate the risk of late deliverables from WEC but have reached a decision point that the added risk to full implementation is outweighing the benefit. The SNC commitment to providing the software, software implementation plan, post-modification testing and operations training with the appropriate level of quality dictates that we request implementation deferral until startup from the subsequent refueling outage (i.e., Fall 2027).
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-2 2.3 Description of Proposed Change The request is a change to the VEGP Unit 3 TS amendment implementation schedule, from prior to startup from the Spring 2026 refueling outage, to implementation prior to startup from the Fall 2027 refueling outage.
- 3. TECHNICAL EVALUATION The plant modifications approved in VEGP Unit 3 Amendment No 203 provide changes to minimize unnecessary PRHR HX actuations that could lead to unnecessary safeguards actuation. Currently the PRHR HX is actuated when one-out-of-two steam generators (SGs) are at Low-2 narrow range level for a preset time delay coincident with one-out-of-two SGs at Low-2 startup feedwater flow. The logic change requires SG Low-2 narrow range level and startup feedwater flow Low-2 in both SGs, which avoids PRHR HX actuation due to a loss of inventory from only one SG while the other SG remains available as a heat sink. The logic change also requires the coincidence of the new RCS Tcold - High function.
The Updated Final Safety Analysis Report (UFSAR) Subsection 15.1.6, Inadvertent Operation of the PRHR Heat Exchanger, is evaluated as a fault of moderate frequency.
Since a reactor trip is initiated as soon as the PRHR HX discharge valves are not fully closed, this event is essentially a reactor trip from the initial condition and requires no separate transient analysis. Inadvertent actuation of the PRHR HX does not result in violation of the core thermal design limits or reactor coolant system overpressure.
While an unnecessary Safeguards actuation is highly undesirable because of the stress it places on the plant and the significant recovery effort required, implementation of the modification is not required for safe operation of the facility or the protection of public health and safety.
The decision to defer implementation of the amendment until the subsequent refueling outage is based on judicious consideration for successful implementation without undue risk to the outage schedule due to continued delays in software delivery. Extending the implementation by one refueling outage will allow adequate time to plan for, and train on, the design change implementation.
4 REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 10 CFR 50.36(c)(2) require a Limiting Condition for Operation (LCO) for actuation signals that form part of the primary success path and which functions or actuates to mitigate a design basis accident. The existing PRHR HX actuation signals meet this criterion. Thus, the proposed implementation change is consistent with the requirements of 10 CFR 50.36.
10 CFR Part 50, Appendix A, General Design Criterion (GDC) 13 "Instrumentation and Control," requires that instrumentation be provided to monitor variables and systems over their anticipated ranges for normal operation, anticipated operational occurrences, and accident conditions to assure adequate safety. Appropriate controls must be provided to maintain variables and systems within prescribed operating ranges. The current PMS
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-3 design meets this criterion. Thus, the proposed implementation change is consistent with the requirements of 10 CFR 50, Appendix A, GDC 13.
10 CFR Part 50, Appendix A, GDC 20, "Protection System Functions," requires a protection system to sense accident conditions and initiate operation of systems important to safety to ensure that acceptable fuel design limits are not exceeded. The existing PMS design meets this criterion. Thus, the proposed implementation change is consistent with the requirements of 10 CFR 50, Appendix A, GDC 20.
10 CFR Part 50, Appendix A, GDC 34, Residual heat removal, requires a safety system to transfer fission product decay heat and other residual heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded. PRHR HX safety analyses show that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are met with the current design. Thus, the proposed implementation change is consistent with the requirements of 10 CFR 50, Appendix A, GDC 34.
4.2 Precedent Letter from Robert E. Martin (NRC) to Mark J. Ajluni (SNC), dated May 10, 2010, Joseph M.
Farley Nuclear Plant Issuance of Amendment Regarding Change of Implementation Date for Amendment No. 176 for Unit 2 (TAC No. ME3445) (ADAMS Accession No. ML101100668).
4.3 Significant Hazards Consideration Southern Nuclear Operating Company (SNC) requests an amendment to the Combined License (COL) for Vogtle Electric Generating Plant (VEGP) Unit 3 to delay the implementation of Amendment No. 203 for one refueling cycle.
By letter dated February 14, 2025 (ADAMS Accession No. ML25045A166), as supplemented by letters dated March 31, July 9, and July 16, 2025 (ML25090A283, ML25190A653, and ML25197A672, respectively), SNC submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request (LAR) that proposed to revise Technical Specifications (TS) 3.3.8, Engineered Safeguards Actuation System Instrumentation, Table 3.3.8-1, to add a new Function 11.b, Reactor Coolant System (RCS)
Cold Leg Temperature (Tcold) - High. NRC issued the amendment on August 8, 2025 (ML25199A048) with implementation required prior to startup from the Spring 2026 refueling outage.
An evaluation to determine whether or not a significant hazards consideration is involved with the proposed amendment was completed by focusing on the three standards set forth in 10 CFR 50.92(c), Issuance of amendment, as discussed below.
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-4
- 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed amendment implementation schedule extension is administrative in nature and does not require any physical plant modifications, physically affect any plant systems or components, or entail changes in plant operation. The proposed changes do not affect the previously evaluated accident probability because the UFSAR Chapter 15 initiating events for analyzed accidents does not change. The proposed change does not adversely affect accident initiators or precursors, and does not alter the design assumptions, conditions, or configuration of the plant or the manner in which the plant is operated or maintained. The proposed change continues to provide that the Engineered Safety Features Actuation System (ESFAS) functions will perform their design basis function.
Therefore, the proposed changes do not result in any increase in probability of an analyzed accident occurring.
The proposed change continues to be supported by the safety analyses described in the UFSAR. Thus, the consequences of the accidents previously evaluated are not adversely affected.
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 kind of accident from any accident previously evaluated?
Response: No The proposed amendment implementation schedule extension is administrative in nature and does not require any physical plant modifications, physically affect any plant systems or components, or entail changes in plant operation. The proposed changes do not involve the installation of any new or different type of equipment or a change to the methods governing normal plant operation. The proposed changes continue to provide the required functional capability, including single-failure protection, of the safety systems for previously evaluated accidents and anticipated operational occurrences. The proposed changes do not adversely impact the function of any related systems, and thus, the changes do not introduce a new failure mode, malfunction, or sequence of events that could adversely affect safety or safety-related equipment.
Therefore, the proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-5
- 3. Does the proposed change involve a significant reduction in a margin of safety?
Response: No.
The proposed amendment implementation schedule extension is administrative in nature and does not require any physical plant modifications, physically affect any plant systems or components, or entail changes in plant operation. The proposed change continues to provide the required functional capability of the safety systems for previously evaluated accidents and anticipated operational occurrences. The proposed change does not change the function of the related systems. The proposed change was evaluated and demonstrated that the safety analyses specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary continue to be met. Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, it is concluded that the proposed amendment does 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.
4.4 Conclusions 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 Commissions 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. Therefore, it is concluded that the requested amendment does 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.
5 ENVIRONMENTAL CONSIDERATION The proposed changes to the Technical Specifications (TS) are described in Section 2 of this Enclosure, which require a license amendment. SNC has evaluated this license amendment request against the criteria for identification of licensing and regulatory actions requiring environmental assessment in accordance with 10 CFR 51.21.
The requested amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9), in that the amendment would 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.
Enclosure to NL-26-0045 Evaluation of Proposed Changes E-6 Accordingly, the proposed amendment meets the eligibility criteria 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 REFERENCES None