ML24025A005
| ML24025A005 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/25/2024 |
| From: | Dennis Galvin Plant Licensing Branch IV |
| To: | Peters K Vistra Operations Company |
| Galvin D | |
| References | |
| EPID L-2023-LRO-0061 | |
| Download: ML24025A005 (1) | |
Text
January 25, 2024 Mr. Ken J. Peters Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Vistra Operations Company LLC Comanche Peak Nuclear Power Plant 6322 N FM 56 P.O. Box 1002 Glen Rose, TX 76043
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 2 - REVIEW OF THE SPRING 2023 STEAM GENERATOR TUBE INSPECTION REPORT (EPID L-2023-LRO-0061)
Dear Mr. Peters:
By letter dated August 17, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23229A598), Vistra Operations Company LLC (Vistra OpCo, the licensee) submitted information summarizing the results of the spring 2023 steam generator inspections performed at Comanche Peak Nuclear Power Plant, Unit No. 2 (Comanche Peak, Unit 2). The inspections were performed during refueling outage 20. The information was submitted in accordance with Comanche Peak Technical Specification (TS) 5.6.9, Steam Generator Tube Inspection Report.
The U.S. Nuclear Regulatory Commission (NRC) staff has completed its review of the information provided by Vistra OpCo and concludes that the licensee provided the information required by Comanche Peak TS 5.6.9 and that no follow-up is required at this time. A summary of the NRC staffs review is enclosed.
If you have any questions, please contact me at 301-415-6256 or via e-mail at Dennis.Galvin@nrc.gov.
Sincerely,
/RA/
Dennis J. Galvin, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-446
Enclosure:
Review of the Spring 2023 Steam Generator Tube Inspection Report cc: Listserv
Enclosure REVIEW OF THE SPRING 2023 STEAM GENERATOR TUBE INSPECTION REPORT COMANCHE PEAK POWER COMPANY LLC AND VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 2 DOCKET NO. 50-446 By letter dated August 17, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23229A598), Vistra Operations Company LLC (the licensee) submitted information summarizing the results of the spring 2023 steam generator (SG) inspections performed at Comanche Peak Nuclear Power Plant Unit No. 2 (Comanche Peak, Unit 2). The inspections were performed during refueling outage (RFO) 20. The information was submitted in accordance with Comanche Peak Technical Specification 5.6.9, Steam Generator Tube Inspection Report.
Comanche Peak, Unit 2 has four Westinghouse Model D5 SGs, each containing 4,570 thermally treated Alloy 600 tubes. Each tube has a nominal outside diameter of 0.750 inch and a nominal wall thickness of 0.043 inch. During SG fabrication, the tube ends were hydraulically expanded over the full depth of the tubesheet. The vertical sections of the tubes are supported on the hot-leg and cold-leg sides by horizonal stainless steel tube support plates with quatrefoil holes.
The cold-leg side also has a stainless steel flow distribution baffle and stainless steel preheater baffle plates, all with drilled holes. Some of the tubes in each SG were hydraulically expanded at selected preheater baffle plates to reduce tube vibration. Two sets of chrome-plated Alloy 600 anti-vibration bars support the U-bend section of the tubes.
The licensee provided the scope, extent, methods, and results of the SG tube inspections in the letter dated August 17, 2023. In addition, the licensee described corrective actions (e.g., tube plugging), if any were taken in response to the inspection findings.
Based on the review of the information provided, the U.S. Nuclear Regulatory Commission (NRC) staff has the following observations:
The licensee reported that no forms of stress corrosion cracking were detected in RFO 20.
Inspections for foreign objects were last performed during RFO 19 and the analysis of the inspection results concluded there was an acceptable operating period of greater than 4.5 effective full power years. Consequently, there was no foreign object inspection completed during RFO 20. The next scheduled foreign object inspection is during RFO 22, which is approximately 4.5 effective full power years after the RFO 19 inspection.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the Comanche Peak technical specifications. In addition, the NRC staff concludes that there are no technical issues that warrant additional follow-up action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation, and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
- by email OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA*
NRR/DNRL/NCSG/BC*
NAME DGalvin PBlechman SBloom DATE 1/25/2024 1/25/2024 1/18/2024 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME JRankin DGalvin DATE 1/25/2024 1/25/2024