ML23023A113
| ML23023A113 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/24/2023 |
| From: | Dennis Galvin Plant Licensing Branch IV |
| To: | Peters K Vistra Operations Company |
| Galvin D | |
| References | |
| EPID L-2022-LRO-0144 | |
| Download: ML23023A113 (4) | |
Text
January 24, 2023 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. 1 - REVIEW OF THE SPRING 2022 STEAM GENERATOR TUBE INSPECTION REPORT (EPID L-2022-LRO-0144)
Dear Mr. Peters:
By letter dated November 3, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22308A178), Vistra Operations Company LLC (Vistra OpCo, the licensee) submitted information summarizing the results of the spring 2022 steam generator inspections performed at Comanche Peak Nuclear Power Plant, Unit No. 1. The inspections were performed during refueling outage 22. 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. 50-445
Enclosure:
Review of the Spring 2022 Steam Generator Tube Inspection Report cc: Listserv
Enclosure REVIEW OF THE SPRING 2022 STEAM GENERATOR TUBE INSPECTION REPORT COMANCHE PEAK POWER COMPANY LLC AND VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-445 By letter dated November 3, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22308A178), Vistra Operations Company LLC (the licensee) submitted information summarizing the results of the spring 2022 steam generator (SG) inspections performed at Comanche Peak Nuclear Power Plant, Unit No 1 (Comanche Peak),.
The inspections were performed during refueling outage 22 (1RF22). The information was submitted in accordance with the Comanche Peak Technical Specification (TS) 5.6.9, Steam Generator Tube Inspection Report.
Comanche Peak, Unit 1, has four Westinghouse Model Delta 76 SGs, each containing 5,532 thermally treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.750 inch and a nominal wall thickness of 0.043 inch (except for rows 1 and 2). Rows 1 and 2 tubes have a nominal wall thickness of 0.044 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 ten horizonal stainless steel tube support plates (TSPs) with trefoil shaped holes. Four sets of chrome-plated stainless steel 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 document referenced above. 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 only detected tube degradation mechanisms during 1RF22 are tube wear at the TSPs and foreign object wear. The limiting flaw analyzed for conditioning monitoring was 12 percent through-wall (TW) for TSP wear and 9 percent TW for foreign object wear. The foreign object wear was first detected during refueling outage 19 (1RF19), has not changed, and eddy current inspection showed that there is no foreign object at this location.
Upper tube bundle visual inspection was performed in SG1. TSPs J, H, and K were inspected, and the deposit loading was found to be acceptable. The licensee stated that overall deposit loading appeared to be less than was observed in 1RF19.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the Comanche Peak TSs. 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 1/23/2023 1/23/2023 1/5/2023 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME JDixon-Herrity DGalvin DATE 1/24/2023 1/24/2023