ML25226A007
| ML25226A007 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 08/20/2025 |
| From: | Samson Lee Plant Licensing Branch IV |
| To: | Reasoner C Wolf Creek |
| Lee S, 301-415-3168 | |
| References | |
| EPID L-2025-LRO-0009 | |
| Download: ML25226A007 (1) | |
Text
August 20, 2025 Mr. Cleveland Reasoner Chief Executive Officer and Chief Nuclear Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839
SUBJECT:
WOLF CREEK GENERATING STATION, UNIT 1 - REVIEW OF SPRING 2024 REFUELING OUTAGE 26 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (EPID L-2025-LRO-0009)
Dear Mr. Reasoner:
By letter dated November 1, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24306A219), as supplemented by letter dated June 24, 2025 (ML25175A120), Wolf Creek Nuclear Operating Corporation (the licensee) submitted a summary of the results of the spring 2024 steam generator (SG) inspections performed at Wolf Creek Generating Station, Unit 1. The inspections were performed during Refueling Outage 26.
The SG tube inspection report was submitted in accordance with Technical Specification (TS) 5.6.10, Steam Generator Tube Inspection Report.
Based on its review, the U.S. Nuclear Regulatory Commission (NRC) staff concludes that the licensee has provided the information required by TS 5.6.10, 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 301-415-3168 or via email at Samson.Lee@nrc.gov.
Sincerely,
/RA/
Samson S. Lee, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482
Enclosure:
Review of the Steam Generator Tube Inspection Report cc: Listserv
Enclosure REVIEW OF SPRING 2024 REFUELING OUTAGE 26 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482 By letter dated November 1, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24306A219), as supplemented by letter dated June 24, 2025 (ML25175A120), Wolf Creek Nuclear Operating Corporation (the licensee), submitted information summarizing the results of the spring 2024 steam generator (SG) inspections at Wolf Creek Generating Station, Unit 1 (Wolf Creek). These inspections were performed during refueling outage 26. The licensee provided additional information about the inspections in its letter dated June 24, 2025.
Wolf Creek has four Westinghouse Model F SGs. Each SG contains 5,626 thermally treated Alloy 600 tubes. Each tube has a nominal outside diameter of 0.688 inches and a nominal wall thickness of 0.040 inches. The tubes are supported by stainless steel tube supports with quatrefoil-shaped holes and V-shaped chrome-plated Alloy 600 anti-vibration bars. The tubes are hydraulically expanded for the full depth of the tubesheet at each end.
The licensee provided the scope, extent, methods, and results of the SG tube inspections in its letter dated November 1, 2024, as supplemented. In addition, the licensee described corrective actions, such as tube plugging, taken in response to the inspection findings.
Based on the review of the information provided by the licensee, the U.S. Nuclear Regulatory Commission (NRC) staff has the following observations:
A single axial indication of outside diameter stress corrosion cracking (ODSCC) was found in a tube in SG A. This was the first detection of axial ODSCC at a tube support plate (TSP) with a dent/ding. The indication was in the tube in row 55 column 46 and located at the 7th cold-leg TSP. The tube was removed from service by plugging.
The area of channel head wastage from a cladding breach in SG A was visually inspected and found similar to previous inspections, so the licensee concluded it remained bounded by the previous analysis and was acceptable for continued operation.
Visual inspections of the three backing rings associated with welds within the feedring in SG B were performed. The inspection results were acceptable; however, some erosion was present. The licensee stated that this area will continue to be monitored in future outages, in accordance with visual inspection plans.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by Wolf Creek Technical Specification 5.6.10, Steam Generator Tube Inspection Report. In addition, the NRC staff concludes there are no technical issues that warrant additional follow-up action currently, 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.
- eConcurrence
- by email NRR-106 OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DNRL/NCSG/BC**
NAME SLee PBlechman SBloom DATE 08/14/2025 08/18/2025 07/07/2025 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME TNakanishi SLee DATE 08/19/2025 08/20/2025