RS-25-079, Supplement No. 5 - Changes to the Clinton Power Station, Unit 1, License Renewal Application
| ML25100A083 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/10/2025 |
| From: | Wilson C Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RS-25-079 | |
| Download: ML25100A083 (1) | |
Text
200 Energy Way Kennett Square, PA 19348 www.ConstellationEnergy.com RS-25-079 10 CFR 50 10 CFR 51 10 CFR 54 April 10, 2025 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
Subject:
Supplement No. 5 - Changes to the Clinton Power Station, Unit 1, License Renewal Application
References:
- 1. Letter from Christopher D. Wilson (Constellation Energy Generation, LLC) to U.S. NRC, Application for Renewed Operating License, dated February 14, 2024 (ML24045A023)
- 2. Letter from Christopher D. Wilson (Constellation Energy Generation, LLC) to U.S. NRC, Supplement No. 1 - Changes to the Clinton Power Station, Unit 1, License Renewal Application, dated November 27, 2024 (ML24332A050)
- 3. Letter from Christopher D. Wilson (Constellation Energy Generation, LLC) to U.S. NRC, Supplement No. 2 - Changes to the Clinton Power Station, Unit 1, License Renewal Application, dated December 20, 2024 (ML24355A050)
- 4. Letter from Christopher D. Wilson (Constellation Energy Generation, LLC) to U.S. NRC, Supplement No. 3 - Changes to the Clinton Power Station, Unit 1, License Renewal Application, dated January 30, 2025 (ML25030A182)
- 5. Letter from Christopher D. Wilson (Constellation Energy Generation, LLC) to U.S. NRC, Supplement No. 4 - Changes to the Clinton Power Station, Unit 1, License Renewal Application, dated March 25, 2025 (ML25084A044)
In Reference 1, Constellation Energy Generation, LLC (CEG) submitted a License Renewal Application (LRA) for Clinton Power Station, Unit 1 (CPS). In References 2, 3, 4, and 5, CEG submitted Supplement Nos. 1, 2, 3, and 4, respectively to the LRA for CPS. The purpose of this letter is to provide Supplement No. 5 to the LRA for CPS. Supplement No. 5 includes one
April 10, 2025 U.S. Nuclear Regulatory Commission Page 2 change to the LRA which revises the description for the Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements program in Appendix B.
Enclosure A to this letter provides a description of the change, and corresponding mark-ups to affected portions of the LRA, thereby supplementing the CPS LRA.
There are no new regulatory commitments contained in this letter.
This submittal has been discussed with the NRC License Renewal Project Manager for the CPS License Renewal project.
Should you have any questions regarding this submittal, please contact Ms. Lydia S.
Dworakowski, Licensing Lead, CPS License Renewal Project, by email at Lydia.Dworakowski@constellation.com.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 10th day of April 2025.
Respectfully, Christopher D. Wilson License Renewal Director Constellation Energy Generation, LLC
Enclosure:
A. Changes to the Clinton Power Station, Unit 1, License Renewal Application cc:
NRC Regional Administrator, Region III NRC Senior Resident Inspector - Clinton Power Station NRC Project Manager (Safety Review), NRR-DNRL NRC Project Manager (Environmental Review), NRR-DNRL NRC Project Manager, NRR-DORL - Clinton Power Station Illinois Emergency Management Agency - Division of Nuclear Safety Wilson, Christopher D Digitally signed by Wilson, Christopher D Date: 2025.04.10 10:31:42 -04'00'
April 10, 2025 Enclosure A Page 1 of 4 Enclosure A Changes to the Clinton Power Station, Unit 1, License Renewal Application Introduction This enclosure contains one change that is being made to the License Renewal Application (LRA) that was identified after submittal of the LRA. The change is described and the affected page number(s) and portion(s) of the LRA are provided. For clarity, entire sentences or paragraphs from the LRA are provided. Previously submitted information is shown in normal font. Additions due to this submittal are highlighted with bolded italics for inserted text, and strikethroughs for deleted text.
April 10, 2025 Enclosure A Page 2 of 4 Change #1 - Revise the Population of Nonsafety-Related Solar-Powered Manholes Affected LRA Section: Appendix B, Section B.2.1.39 LRA Page Numbers: B-166 and B-167 Description of Change:
The population of nonsafety-related manholes equipped with solar-powered level monitoring, indication and dewatering hardware is being revised to remove four manholes, i.e., 1MESVC1, 1MESVC2, 1MESVC3 and 1MESVC4, from the scope of the Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements program. These four manholes contain cabling associated with the Emergency Reserve Auxiliary Transformer (ERAT) on-load tap changer power supply from the ERAT Mechanically Switched Capacitors (MSC). Detailed review of additional design information and station operating procedure guidance demonstrate that the ERAT (RAT B) on-load tap changers are not required to be energized for Station Blackout recovery.
Accordingly, LRA Appendix B, Section B.2.1.39 is revised.
April 10, 2025 Enclosure A Page 3 of 4 LRA Appendix B, Section B.2.1.39, Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements, pages B-166 and B-167 are revised as shown below. The LRA markup includes changes submitted in Supplement 1, dated November 27, 2004, which clarified the annual inspection frequency for the nonsafety-related manholes/cable vaults via Change #25 and is duplicated here as an aid to the reviewer.
B.2.1.39 Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Program Description The Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements aging management program is a new condition monitoring program that will be used to manage the effects of reduced insulation resistance of non-EQ, in scope, inaccessible power cables. For this program, power is defined as greater than or equal to 400 volts (V).
These inaccessible power cables may at times be exposed to significant moisture. Power cable exposure to significant moisture may cause reduced insulation resistance that can potentially lead to failure of the cable's insulation system.
Periodic actions will be taken to prevent inaccessible cables from being exposed to significant moisture. Significant moisture is defined as periodic exposure to moisture that lasts more than a few days (e.g., cable wetting or submergence in water). Periodic exposures that last less than a few days (e.g., normal rain and drain) are not significant. This aging management program will implement actions that can prevent cable exposure to significant moisture by inspecting manholes / cable vaults for the non EQ, in scope, inaccessible power cables for water collection and subsequent draining or other corrective action, as needed.
Prior to the period of extended operation, the frequency for inspections for accumulated water will be established and adjusted based on plant specific operating experience with cable wetting or submergence. The inspections are performed periodically based on water accumulation over time.
Manholes / cable vaults equipped with solar powered monitoring and alarms will be inspected at least once annually.
Manholes / cable vaults equipped with 120 VAC powered level monitoring and alarms that result in consistent, subsequent pump out of accumulated water prior to wetting or submergence of cables will be inspected at least once every five years.
Clinton has 13 17 manholes / cable vaults containing License Renewal in scope cables, of which 10 are safety-related and three seven are nonsafety-related. All 10 safety-related manholes / cable vaults are equipped with SmartVault and SmartCover monitoring, level indication and dewatering hardware supplied by 120 VAC. The 10 safety-related manholes / cable
April 10, 2025 Enclosure A Page 4 of 4 vaults equipped with SmartVault and SmartCover monitoring, will be inspected on a five-year frequency. The first inspections for license renewal will be completed prior to the period of extended operation.
The three seven nonsafety-related manholes / cable vaults are equipped with solar powered level monitoring, indication and dewatering hardware. The three seven nonsafety-related manholes / cable vaults will be inspected on an annual inspection frequency.
The first inspections for license renewal will be completed prior to the period of extended operation.
Inspections for water accumulation will also be performed after event driven occurrences such as heavy rain or flooding. Plant specific parameters are established for the initiation of an event-driven inspection.
The three seven manholes / cable vaults equipped with solar powered monitoring and alarms will be inspected following event driven occurrences, such as heavy rain or flooding.
The 10 manholes / cable vaults equipped with 120 VAC powered level monitoring and alarms, will be inspected following event driven occurrences, such as heavy rain or flooding, when level monitoring indicates water is accumulating.
The cables within the scope of this program will be tested using one or more proven tests for detecting reduced insulation resistance of the cables insulation system due to wetting or submergence, such as dielectric loss (dissipation factor or power factor), AC voltage withstand, partial discharge, step voltage, time domain reflectometry, insulation resistance and polarization index, line resonance analysis, or other testing that is state of the art at the time the test is performed. The cables will be tested at least once every six years. More frequent testing may occur based on test results and operating experience.