ML23256A267

Review of the Fall 2022 Steam Generator Tube Inspection Report

ML23256A267
Person / Time
Site:	Surry
Issue date:	09/21/2023
From:	Klos L NRC/NRR/DORL/LPL2-1
To:	Carr E Virginia Electric & Power Co (VEPCO)
References
EPID: L-2023-LRO-0012
Download: ML23256A267 (1)

Text

September 21, 2023

Mr. Eric S. Carr President - Nuclear Operations and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

SURRY POWER STATION, UNIT 1 - REVIEW OF THE FALL 2022 STEAM GENERATOR TUBE INSPECTION REPORT (EPID: L-2023-LRO-0012)

Dear Mr. Carr:

By letter dated March 24, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23086B917), Virginia E lectric and Power Company (the licensee),

submitted information summarizing the results of the fall 2022 steam generator inspections performed at Surry Power Station, Unit 1, during the refueling outage.

The U.S. Nuclear Regulatory Commission (NRC) staff has completed its review of the report and concludes that the licensee provided the information required by their technical specifications and that no follow-up is required at this time. The enclosure documents the NRC staffs review of the submittal.

If you have any questions, please contact me at (301) 415-5136, or via email at John.Klos@nrc.gov.

Sincerely,

/RA/

L. John Klos, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket Nos. 50-280

Enclosure:

Review of the Steam Generator Tube Inspection Report

cc: Listserv REVIEW OF THE FALL 2022 STEAM GENERATOR

TUBE INSPECTION REPORT

VIRGINIA ELECTRIC AND POWER COMPANY

SURRY POWER STATION, UNIT NO. 1

DOCKET NOS. 50-280

By letter dated March 24, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23086B917), Virginia Electric and Power Company (the licensee),

submitted information summarizing the results of the fall 2022 steam generator inspections performed at Surry Power Station, Unit 1, performed during its 31st refueling outage (RFO31).

The three replacement steam generators (SGs) at Surry, Unit 1, were installed in 1981.

Westinghouse fabricated the replacement SGs, and each SG contains 3,342 thermally treated Alloy 600 tubes that have a nominal outside diameter of 0.875 inches and a nominal wall thickness of 0.050 inches. The tubes were hydraulically expanded at both ends for the full length of the tubesheet and are supported by stainless steel tube support plates. The U-bends of the tubes installed in rows 1 through 8 were thermally stress relieved after bending. The moisture separators were upgraded in 1995 and the feedrings were replaced in 2010.

In its letter dated March 24, 2023, the licensee provided the scope, extent, methods, and results of their SG tube inspections in the document referenced above. 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:

Improper heat treatment in high-row tubes (-2 sigma tubes) were identified in 19, 22, and 3 tubes of SGs A, B, and C, respectively. One of the 19 tubes in SG A was subsequently plugged. These tubes in SGs A, B and C were examined full length with an array probe.

The licensee reported that there are no low-row tubes with indications of improper heat treatment.

Dent and ding inspections performed during RFO31 included 100 percent of all dents and dings 2 volts in the hot leg straight section and 100 percent of all dents and dings 5 volts in the U-bend and cold-leg sections of the tubes.

The licensee reported that no corrosion related degradation, such as stress corrosion cracking, was detected.

Based on a review of the information provided, the staff concludes that the licensee provided the information required by their technical specifications.

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.

Enclosure

ML23256A267 NRR-106 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DNRL/NCSG/BC NAME JKlos KGoldstein SBloom DATE 9/13/2023 9/14/2023 9/7/2023 OFFICE NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME MMarkley JKlos DATE 9/21/2023 9/21/2023