ML24247A221
| ML24247A221 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/29/2024 |
| From: | Marshall T Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML24247A221 (1) | |
Text
Sequoyah Nuclear Plant, P.O. Box 2000, Soddy Daisy, Tennessee 37384 August 29, 2024 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Unit 2 Renewed Facility Operating License No. DPR-79 NRC Docket No. 50-328
Subject:
Notification of Deviation from Pressurized Water Reactor Owners Group (PWROG) Letter OG-21-160, "NEI 03-08 Needed Guidance: PWR Lower Radial Support Clevis Insert X-750 Bolt Inspection Requirements," September 1, 2021 In accordance with Appendix B, Section 8.1.c of Nuclear Energy Institute (NEI) 03-08, "Guideline for the Management of Materials Issues," Revision 4, the Tennessee Valley Authority (TVA) is notifying the U.S. Nuclear Regulatory Commission (NRC) that Sequoyah Nuclear Plant (SQN), Unit 2 has processed a deviation from "Needed" guidance in OG-21-160, PWR Lower Radial Support Clevis Insert X-750 Bolt Inspection Requirements. PWROG Letter OG-21-160 has a requirement for pressured water reactor (PWR) plants to perform one of three options: (1) Proactive replacement of clevis insert bolts, (2) Ultrasonic Testing (UT) of clevis insert bolts with contingency for bolt replacement, or (3) UT of clevis insert bolts with contingency operability assessment. The "Needed" guidance shall be implemented at Westinghouse-and Combustion Engineering-designed PWR units at the next scheduled core barrel pull after July 1, 2023, or prior to 55 calendar years of plant operation, whichever comes first. SQN Unit 2 has been operating approximately 42 years.
SQN Unit 2 is scheduled to perform a core barrel removal during the fall 2024 refueling outage, U2R26, to perform certain 10-year inservice inspection and Material Reliability Program (MRP-227) examinations. SQN also had planned to implement Option 3, UT of clevis insert bolts with contingency operability assessment during the outage. As a result of equipment issues and for business reasons, SQN has already entered the refueling outage 53 days in advance of the planned start. Moreover and the reason for this deviation, based on the Unit 1 spring 2024 refueling outage clevis insert bolt examination results, wherein 38 of 48 bolts had indications, and Unit 2 has similar operating conditions and operating time as Unit 1, SQN now believes Option 1 is more prudent. A replacement bolting pattern analysis (RBPA) developed by Westinghouse is intended to be used for the bolt replacement. The lead time to generate the RBPA and to procure the bolts is beyond the original U2R26 fall start date and the current schedule for replacement is Spring 2028.
U.S. Nuclear Regulatory Commission Page 2 August 29, 2024 Westinghouse has provided justification for continued operation and loose parts assessment for one cycle beyond the outage of discovery.
NEI 03-08 allows deviation from "Needed" elements with the appropriate justification and documentation. The deviation was documented in accordance with TVAs procedures and programs, and approved by the appropriate levels of TVA management.
This letter is being transmitted for information only and TVA SQN is not requesting any action from the NRC.
There are no new regulatory commitments associated with this submittal. Should you have any questions, please contact Rick Medina, Site Licensing Manager at (423) 843-8129 or rmedina4@tva.gov.
Respectfully, Thomas Marshall Site Vice President Sequoyah Nuclear Plant cc:
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant NRC Project Manager - Sequoyah Nuclear Plant NRC NRR Director Marshall, Thomas B.
Digitally signed by Marshall, Thomas B.
Date: 2024.08.29 11:53:21 -04'00'