ML21028A508

Review of the Spring 2020 Steam Generator Tube Inspection Report

ML21028A508
Person / Time
Site:	Byron
Issue date:	02/03/2021
From:	Joel Wiebe Plant Licensing Branch III
To:	Rhoades D Exelon Generation Co
Wiebe J
References
EPID L-2020-LRO-0056
Download: ML21028A508 (3)

Text

February 3, 2021 Mr. David P. Rhoades Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)

Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

BYRON NUCLEAR POWER STATION, UNIT 1 - REVIEW OF THE SPRING 2020 STEAM GENERATOR TUBE INSPECTION REPORT (EPID L- 2020- LRO- 0056)

Dear Mr. Rhoades:

By letter dated September 10, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20253A042), Exelon Generation Company, LLC (the licensee),

submitted information summarizing the results of the spring 2020 steam generator (SG) inspections performed at Byron Nuclear Power Station, Unit 1. The inspections were performed during refueling outage 23. The SG tube inspection report was submitted in accordance with Technical Specification 5.6.9, Steam Generator (SG) 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 Technical Specification 5.6.9, and that no follow-up is required at this time. A summary of the NRC staff's review is enclosed.

If you have any questions, please contact me at 301-415-6606 or via e-mail at Joel.Wiebe@nrc.gov Sincerely,

/RA/

Joel S. Wiebe, Senior Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454

Enclosure:

Review of the Byron, Unit 1, Steam Generator Tube Inspection Report cc: Listserv

REVIEW OF THE SPRING 2020 STEAM GENERATOR TUBE INSPECTION REPORT EXELON GENERATION COMPANY, LLC BYRON STATION, UNIT NO. 1 DOCKET NO. STN 50-454 By letter dated September 10, 2020 (Agencywide Documents Access and Management System Accession No. ML20253A042), Exelon Generation Company, LLC (the licensee), submitted information summarizing the results of the spring 2020 steam generator (SG) inspections performed at Byron Nuclear Power Station, Unit 1 (Byron Unit 1). The inspections were performed during refueling outage (RFO) 23.

Byron Unit 1 has four replacement Babcock & Wilcox SGs. These replacement SGs were installed during RFO 8 in 1998. Each SG contains 6,633 tubes made from thermally treated Alloy 690 material. Each tube has a nominal outside diameter of 0.6875 inches and a nominal wall thickness of 0.040 inches. The tubes were hydraulically expanded at both ends for the full length of the tubesheet and are supported by a number of stainless steel lattice grid structures and fan bars.

The licensee provided the scope, extent, methods, and results, of the SG tube inspections in the letter 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 licensee reported some deposit accumulation at the lattice grids and on the tube surfaces on the hot-leg side at the uppermost (9th) support location in the 1D SG. The licensee reported that the corresponding cold leg lattice grids and tube surfaces were relatively free of deposit accumulation.

Based on a review of the information provided, the NRC 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

ML21028A508 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DNRL/NCSG NAME JWiebe SRohrer SBloom DATE 02/02/2021 02/01/2021 12/08/2020 OFFICE NRR/DORL/LPL3/BC NRR/DORL/LPL3/PM NAME NSalgado JWiebe DATE 02/03/2021 02/03/2021