ML18297A069

Review of the Fall 2017 Steam Generator Tube Inspection Report

ML18297A069
Person / Time
Site:	Comanche Peak
Issue date:	10/24/2018
From:	O'Banion M Plant Licensing Branch IV
To:	Peters K Vistra Operations Company
Watford M, 301-415-1233
References
EPID L-2018-LRO-0019
Download: ML18297A069 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 24, 2018 Mr. Ken J. Peters Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Vistra Operations Company LLC Comanche Peak Nuclear Power Plant 6322 N FM 56 P.O. Box 1002 Glen Rose, TX 76043

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 1 - REVIEW OF THE FALL 2017 STEAM GENERATOR TUBE INSPECTION REPORT (EPID L-2018-LR0-0019)

Dear Mr. Peters:

By letter dated April 19, 2018 (Agencywide Documents Access and Management System Accession No. ML18128A191 ), Vistra Operations Company LLC (the licensee) submitted information to the U.S. Nuclear Regulatory Commission (NRC) summarizing the results of the fall 2017 steam generator (SG) tube inspections performed at the Comanche Peak Nuclear Power Plant (CPNPP), Unit No. 1, during Unit 1 Refueling Outage 19. The SG tube inspection report was submitted in accordance with CPNPP Technical Specification (TS) 5.6.9, "Unit 1 Model D76 and Unit 2 Model D5 Steam Generator Tube Inspection Report."

Based on its review, the NRC staff concludes that the licensee provided the information required by CPNPP TS 5.6.9, and that no followup is required at this time. A summary of the NRC staff's review is enclosed. If you have any questions, please call me at 301-415-1233 or via e-mail at Margaret.O'Banion@nrc.gov.

Sincerely, Margaret W. O'Banion, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-445

Enclosure:

Review of SG Tube Inspection Report cc: Listserv

REVIEW OF THE FALL 2017 REFUELING OUTAGE 19 STEAM GENERATOR TUBE INSPECTION REPORT VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-445 By letter dated April 19, 2018 (Agencywide Documents Access and Management System Accession No. ML18128A191 ), Vistra Operations Company LLC (the licensee) submitted information summarizing the results of the fall 2017 steam generator (SG) tube inspections performed at the Comanche Peak Nuclear Power Plant (CPNPP), Unit No. 1, during Unit 1 Refueling Outage 19 (1RF19). The SG tube inspection report has been submitted in accordance with CPNPP Technical Specification (TS) 5.6.9, "Unit 1 Model D76 and Unit 2 Model D5 Steam Generator Tube Inspection Report."

CPNPP, Unit No. 1, has four Westinghouse model Delta 76 SGs that were installed during the 121h refueling outage (1RF12). Each SG has 5,532 thermally treated Alloy 690 tubes, which have a nominal outside diameter of 0. 750 inches and a nominal wall thickness of 0.043 inches (except tubes in Rows 1 and 2, which have a nominal wall thickness of 0.044 inches). The tubes have a triangular pitch of 1.030 inches and were hydraulically expanded at each end for the full depth of the 24.315-inch thick tubesheet (including the 0.25-inch cladding at the bottom of the tubesheet). The tubes are supported by ten Type 405 stainless steel tube support plates.

The licensee provided the scope, extent, methods, and results of its SG tube inspections in the letter dated April 19, 2018. After reviewing the information provided by the licensee, the NRC staff has the following observation:

• During 1RF19, the licensee performed visual inspections of the channel heads in each SG. At several locations, reddish surface deposits were observed at an elevation consistent with the nozzle drain plug elevation and at an elevation just below the Z-seam weld. No visible degradation of the cladding was observed. The licensee suspects that the deposits are an artifact of the reactor coolant system water levels within the SG during various hold points as the reactor coolant system was drained down to mid-loop.

Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by CPNPP TS 5.6.9. In addition, the staff concludes that there are no technical issues that warrant followup action at this time because ( 1) the inspections appear to be consistent with the objective of detecting potential SG tube degradation and (2) the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.

Enclosure

ML18297A069 *memo dated October 22, 2018 OFFICE NRR/D0RL/LPL4/PM NRR/D0RL/LPL4/LA NRR/DMLR/MCCB/BC* NRR/D0RL/LPL4/BC NRR/D0RL/LPL4/PM NAME MO'Banion PBlechman SBloom RPascarelli MO'Banion DATE 10/24/2018 10/24/2018 10/22/2018 10/24/2018 10/24/2018