ML25178B389
| ML25178B389 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/02/2025 |
| From: | Kimberly Green NRC/NRR/DORL/LPL2-2 |
| To: | |
| Shared Package | |
| ML25178B363 | List: |
| References | |
| EPID L2025-LRM-0067 | |
| Download: ML25178B389 (1) | |
Text
July 2, 2025 LICENSEE:
Tennessee Valley Authority FACILITY:
Sequoyah Nuclear Plant, Units 1 and 2
SUBJECT:
SUMMARY
OF JUNE 12, 2025, PUBLIC TELECONFERENCE WITH TENNESSEE VALLEY AUTHORITY TO DISCUSS A PROPOSED ALTERNATIVE REQUEST REGARDING THERMAL RELIEF VALVES (EPID L-2025-LRM-0067)
On June 12, 2025, the U.S. Nuclear Regulatory Commission (NRC) staff held a public meeting via teleconference with representatives of the Tennessee Valley Authority (TVA) to discuss a proposed alternative request for Sequoyah Nuclear Plant (Sequoyah), Units 1 and 2. The meeting notice and agenda for this meeting, dated June 2, 2025, are available at Agencywide Documents Access and Management System (ADAMS) Accession No. ML25153A013. The licensees slides for the meeting are available at ADAMS Accession No. ML25160A193. A list of the meeting attendees is enclosed.
TVA stated that it plans to submit an alternative request for Sequoyah, Units 1 and 2, in accordance with paragraph 50.55a(z)(2) of Title 10 of the Code of Federal Regulations. The request would apply to four alternatives for Unit 1, one alternative for Unit 2, and one common thermal relief valve (TRV). The duration of the proposed alternative would be for remainder of the Sequoyah, Unit 2, fourth 10-year inservice test (IST) interval or until successful testing is completed in accordance with the American Society of Mechanical Engineers (ASME)
Operation and Maintenance (OM) Code Mandatory Appendix I, I-1390, Test Frequency, Classes 2 and 3 Pressure Relief Devices that are Used for Thermal Relief Application, whichever is sooner. The current due dates for the testing of the six valves are in September 2025.
TVA explained that it needs the alternative request due to the limited availability of replacement valve TRV repair parts to support the IST by the scheduled due dates. Two valves are scheduled to be tested during the Sequoyah, Unit 1, outage in October 2025, but this is past the due date in September 2025, but they cannot be tested online. TVA stated that if a forced outage occurs prior to the Unit 1 outage in October 2025, it will evaluate the ability to install the two replacement valves based on plant conditions, outage scope, and duration. TVA is awaiting replacement parts or valves and an opportunity to perform the testing for the other four valves.
Until the required testing is completed, TVA said that it has issued a Standing Order to update clearance software to add a note to all the relevant valves to ensure a vent path is established.
TVA elaborated on the basis for the proposed alternative, explaining that due to a design change (due to obsolescence) back in 2015, a large number of valves reached the end of the 10-year testing interval at the same time, however, TVA stocking levels and manufacturing lead times prohibit the option to use a pre-tested spare in accordance with the ASME OM Code. TVA explained that it has one spare valve in stock but it is under a Quality Assurance (QA) hold. This QA hold renders the valve unusable until the valve can be appropriately refurbished. TVA stated that instead of shipping these valves back to the vendor, it has chosen to order replacement parts and perform the refurbishment in house. This will enable faster refurbishment and the creation of an available spare for set point testing until the ordered spares arrive.
TVA briefly covered the maintenance history of the six TRVs and noted that five of the six valves had been replaced in 2015 and there has been no identification of leakage since the installation, and there has been no leakage identified in the sixth valve.
TVA plans to request that the duration of the alternative be through the remainder of the Sequoyah, Unit 2, fourth 10-year IST interval or until the successful testing is completed in accordance with Mandatory Appendix I, I-1390 for each of the valves that are subject to the alternative request, whichever is sooner. TVA noted that if it is able to complete the testing of any of the subject valves prior to the NRCs approval of the request, it will supplement the alternative request accordingly. The Sequoyah, Unit 2, fourth 10-year IST interval is currently scheduled to end on June 30, 2026, but TVA noted that it may be extended in accordance with the ASME OM Code, Section ISTA-2130(c).
The NRC staff suggested that TVA clarify in the alternative request that it applies to both Sequoyah, Units 1 and 2, since the expiration date of the IST interval mentioned is only for Unit 2. The staff also suggested that TVA include in the request that there has been no other maintenance or leakage history for the subject valves. In reference to the end of the IST interval date and the potential to extend it, the staff suggested that it might be helpful if TVA noted the extension date in number of days or the end date. Lastly, the staff referred TVA to the summaries of the two public meetings held by the NRC staff concerning similar alternative requests for Comanche Peak. This will allow TVA to gather any useful insights to support its own request.
TVA plans to submit the alternative request by June 30, 2025.
No regulatory decisions were made at this meeting.
No comments or public meeting feedback forms were received.
Please direct any inquiries to me at 301-415-1627 or Kimberly.Green@nrc.gov.
/RA/
Kimberly J. Green, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosure:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES JUNE 12, 2025, TELECONFERENCE WITH TENNESSEE VALLEY AUTHORITY PROPOSED ALTERNATIVE REQUEST REGARDING THERMAL RELIEF VALVES SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 Name Organization Kim Green U.S. Nuclear Regulatory Commission (NRC)
Tom Scarbrough NRC Robert Hsu NRC Gurjendra Bedi NRC Nick Hansing NRC Stewart Bailey NRC Evan Robinson NRC Russ Wells Tennessee Valley Authority (TVA)
Jesse Baron TVA Paul Parashak TVA Shad Wright TVA Mark Gowin TVA Andy McNeil TVA Channing Mitchell TVA
ML25178B363 (Package)
ML25160A193 (Slides)
ML25153A013 (Meeting Notice)
ML25178B389 (Meeting Summary)
- via eConcurrence NRC-001 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME KGreen ABaxter DWrona KGreen DATE 6/27/2025 7/1/2025 7/1/2025 7/2/2025