ML25357A045
| ML25357A045 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 01/07/2026 |
| From: | William Orders Plant Licensing Branch IV |
| To: | Heflin A Arizona Public Service Co |
| Orders, William | |
| References | |
| EPID L-2025-LRO-0053 | |
| Download: ML25357A045 (0) | |
Text
January 7, 2026 Mr. Adam Heflin Executive Vice President/
Chief Nuclear Officer Mail Station 7605 Arizona Public Service Company P.O. Box 52034 Phoenix, AZ 85072-2034
SUBJECT:
PALO VERDE NUCLEAR GENERATING STATION, UNIT 1 - REVIEW OF THE SPRING 2025 STEAM GENERATOR TUBE INSPECTION REPORT (EPID L-2025-LRO-0053)
Dear Mr. Heflin:
By letter dated September 18, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25261A357), Arizona Public Service Company (the licensee) submitted information summarizing the results of the spring 2025 steam generator (SG) inspections performed at Palo Verde Nuclear Generating Station, Unit 1. These inspections were performed during refueling outage 25. The SG tube inspection report was submitted in accordance with Technical Specification (TS) 5.6.8, Steam Generator Tube Inspection Report.
The U.S. Nuclear Regulatory Commission (NRC) staff has completed its review of the submittal and concludes that the licensee provided the information required by Palo Verde, Unit 1, TS 5.6.8. The staff concludes that there are no technical issues that warrant follow-up actions at this time. The staffs review summary is enclosed.
If you have any questions, please contact me at (301) 415-3329 or via email at William.Orders@nrc.gov.
Sincerely,
/RA/
William Orders, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-528
Enclosure:
Review of the SG Tube Inspection Report cc: Listserv
Enclosure REVIEW OF THE SPRING 2025 STEAM GENERATOR TUBE INSPECTION REPORT ARIZONA PUBLIC SERVICE COMPANY PALO VERDE NUCLEAR GENERATING STATION, UNIT 1 DOCKET NO. STN 50-528 By letter dated September 18, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25261A357), Arizona Public Service Company (the licensee) submitted information summarizing the results of the spring 2025 steam generator (SG) inspections performed at Palo Verde Nuclear Generating Station (Palo Verde), Unit 1. These inspections were performed during refueling outage 25 (U1R25). Palo Verde, Unit 1,Technical Specification (TS) 5.6.8, Steam Generator Tube Inspection Report, requires that a report be submitted within 180 days after the initial entry into hot shutdown (MODE 4) following completion of an inspection of the SGs in accordance with TS 5.5.9, Steam Generator (SG)
Program.
Palo Verde, Unit 1, has two replacement SGs designed by Combustion Engineering and manufactured by Asea Brown Boveri Ltd (ABB)/Ansaldo. Each SG contains 12,580 thermally treated Alloy 690 tubes with an outside diameter of 0.750 inches and a wall thickness of 0.042 inches. Ferritic stainless steel eggcrate tube supports, diagonal bars, and vertical straps support the tubes at various locations.
The licensee provided the scope, extent, methods, and results of the SG tube inspections in the letter dated September 18, 2025. In addition, the licensee described corrective actions (e.g.,
tube plugging) 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:
A total of 20 tubes were plugged (7 in SG 11 and 13 in SG 12) due to tube support wear, possible loose parts (PLPs), and preventatively.
Table 2 states that no tubes were plugged in SG 11 due to PLPs; however, the table of PLPs and PLIs (possible loose part with indication) in Appendix D identifies the tube at Row 32 Column 79 (R32C79) as a tube TBP (to be plugged). Appendix F states that this tube was plugged; therefore, there is no tube integrity concern.
Table 2 states that there were two tubes in SG 12 with vertical strap wear indications greater than or equal to 40 percent through wall (TW); however, Appendix C includes three tubes in SG 12 with vertical strap wear indications greater than 40 percent TW (tubes R111C164, R140C71, and R120C63). Appendix F states that these three tubes were all plugged; therefore, there is no tube integrity concern.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by its TS. In addition, the staff concludes that there are no technical issues that warrant 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.
ML25357A045 NRR-106 OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DNRL/NCSG/BC NAME Worders PBlechman SBloom DATE 12/29/2025 12/23/2025 12/31/2025 OFFICE NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME TNakanishi WOrders DATE 01/05/2026 01/07/2026