ML21252A537

Review of the Spring 2017 and Fall 2020 Steam Generator Tube Inspection Reports (Epids L-2021-LRO-0021 and L-2021-LRO-0028)

ML21252A537
Person / Time
Site:	Robinson
Issue date:	09/22/2021
From:	Klos L Plant Licensing Branch II
To:	Kapopoulos E Duke Energy Progress
Klos L
References
EPIDS L-2021-LRO-0021 AND L-2021-LRO-002
Download: ML21252A537 (4)

Text

September 22, 2021

Mr. Ernest J. Kapopoulos, Jr.

H. B. Robinson Steam Electric Plant Site Vice President Duke Energy Progress, LLC 3581 West Entrance Road, RNPA01 Hartsville, SC 29550

SUBJECT:

H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 - REVIEW OF THE SPRING 2017 AND FALL 2020 STEAM GENERATOR TUBE INSPECTION REPORTS (EPIDS L-2021-LRO-0021 AND L-2021-LRO-0028)

Dear Mr. Kapopoulos:

By letters dated September 18, 2017, and May 26, 2021 (Agencywide Documents Access and Management System Accession Nos. ML17262A059 and ML21147A263), Duke Energy Progress, LLC (the licensee, Duke Energy), submitted information summarizing the results of the spring 2017 and fall 2020 steam generator inspections performed at H. B. Robinson Steam Electric Plant, Unit 2. The inspections were performed during refueling outage (RFO) 30 (spring 2017) and RFO 32 (fall 2020).

The NRC staff has completed its review of Duke Energys submittals, as documented in the enclosed evaluation. The NRC staff concludes that Duke Energy has provided the information required by the technical specifications and that no additional follow-up is required at this time.

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

Sincerely,

/RA/

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

Docket No. 50-261

Enclosure:

Review of Spring 2017 and Fall 2020 Steam Generator Tube Inspection Reports

cc: Listserv REVIEW OF SPRING 2017 AND FALL 2020

STEAM GENERATOR TUBE INSPECTION REPORTS

DUKE ENERGY PROGRESS, LLC

H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2

DOCKET NO. 50-261

By letters dated September 18, 2017, and May 26, 2021 (Agencywide Documents Access and Management System Accession Nos. ML17262A059 and ML21147A263), Duke Energy Progress, LLC (the licensee, Duke Energy), submitted information summarizing the results of the spring 2017 and fall 2020 steam generator (SG) inspections performed at H. B. Robinson Steam Electric Plant, Unit 2 (Robinson Unit 2). The inspections were performed during refueling outage (RFO) 30 (spring 2017) and RFO 32 (fall 2020).

Robinson Unit 2 has three Westinghouse Electric Companys model 44F SGs, each containing 3,214 thermally treated Alloy 600 tubes. The tubes have a nominal outside diameter of 0.875 inches and a nominal wall thickness of 0.050 inches. The tubes are supported by stainless steel tube support plates with quatrefoil-shaped holes and V-shaped Alloy 600 anti-vibration bars.

The licensee provided the scope, extent, methods, and results of the SG tube inspections in the letters 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:

• During RFO 30, two circumferential primary water stress corrosion cracking (PWSCC) indications were identified in the hot-leg tube ends. The H* (H-star) alternate repair criteria allows those tubes to remain in service since these indications are more than 18.11 inches below the top of the tubesheet. No new circumferential PWSCC indications were identified in the tube ends during RFO 32.

• During RFO 32, the licensee dispositioned 26 historical foreign object (FO) wear indications as historical no change (HNC) based on confirming that the eddy current signal for the indications had not changed for three successive inspections. There were 11 in the A SG, 7 in the B SG, and 8 in the C SG reclassified from historical FO wear to HNC.

• A total of six tubes were plugged during RFO 30; one in the B SG was plugged due to wear at a tube support plate and, in the C SG, two were plugged due to FO wear and three were preventively plugged to bound a FO. Only one tube was plugged during RFO 32 and it was due to wear at a tube support plate in the C SG.

Enclosure

Based on a review of the information provi ded, the NRC staff concludes that the licensee provided the information required by their tec hnical 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.

ML21252A537 *by e-mail OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-2/LA NRR/DNRL/NCSG/BC NAME JKlos RButler SBloom*

DATE 9/9/2021 9/16/2021 8/30/2021 OFFICE NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-1/PM NAME DWrona JKlos DATE 9/17/2021 9/22/2021