ML20321A211

NRR E-mail Capture - Summer, Unit 1 - Final RAIs for the SG Tube Inspection Report Review

ML20321A211
Person / Time
Site:	Summer
Issue date:	11/16/2020
From:	Vaughn Thomas NRC/NRR/DORL/LPL2-1
To:	Gao Y Dominion Energy South Carolina
References
Download: ML20321A211 (4)

Text

From: Thomas, Vaughn Sent: Monday, November 16, 2020 8:46 AM To: Yan.Gao@dominionenergy.com

Subject:

Summer, Unit 1 - Final RAIs for the SG Tube Inspection Report Review Attachments: Summer U1_ Final SG TIR_RAI 57.doc Good Morning Yan, The attached file constitutes the staffs issuance of the final RAIs for the review of the Summer Fall 2018 SG Tube Inspection Report. The licensee is requested to provide its response to the staff RAIs within 30 days from todays date, November 16, 2020 (due December 15, 2020).

Thank you, Vaughn Thomas, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Vaughn.Thomas@nrc.gov 301-415-5897

Hearing Identifier: NRR_DRMA Email Number: 889 Mail Envelope Properties (BLAPR09MB69009287A1733EA1E54E9B79F4E30)

Subject:

Summer, Unit 1 - Final RAIs for the SG Tube Inspection Report Review Sent Date: 11/16/2020 8:46:22 AM Received Date: 11/16/2020 8:46:22 AM From: Thomas, Vaughn Created By: Vaughn.Thomas@nrc.gov Recipients:

"Yan.Gao@dominionenergy.com" <Yan.Gao@dominionenergy.com>

Tracking Status: None Post Office: BLAPR09MB6900.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 538 11/16/2020 8:46:22 AM Summer U1_ Final SG TIR_RAI 57.doc 58748 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION OFFICE OF NUCLEAR REACTOR REGULATION Issue Date: November 16, 2020 Steam Generator Tube Inspection Report, Fall 2018 South Carolina Electric & Gas Dockets: 05000395-PWR-Summer EPIDS: L-2019-LRO-0105 Questions Question Number: 77 By letter dated May 14, 2019 (Agencywide Documents Access and Management System Accession No. ML19134A372), Dominion Energy South Carolina, Inc., submitted information summarizing the results of the fall 2018 steam generator (SG) inspections performed at Virgil C. Summer Nuclear Station (VCSNS), Unit 1. The inspections were performed during refueling outage (RFO) 24.

In Appendix A of Part 50 of Title 10 of the Code of Federal Regulations (10 CFR), General Design Criteria (GDC) 14, 15, 30, 31, and 32, define requirements for the structural and leakage integrity of the RCPB. As part of the RCPB, the SG tubes must also meet the requirements of 10 CFR 50.55a with respect to inspection and repair requirements of the ASME Code. All pressurized water reactors have Technical Specifications (TS) according to 10 CFR 50.36 that include a SG Program with specific criteria for the structural and leakage integrity, repair, and inspection of SG tubes. VCSNS, Unit 1 TS Section 6.9.1.12 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 performed in accordance with TS Section 6.8.4.k, which requires that a SG Program be established and implemented to ensure SG tube integrity is maintained.

To complete its review of the inspection, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following additional information;

1. Please discuss if there were any anomalies noted during the primary side visual inspections performed on each SG.

Question Number: 78 By letter dated May 14, 2019 (Agencywide Documents Access and Management System Accession No. ML19134A372), Dominion Energy South Carolina, Inc., submitted information summarizing the results of the fall 2018 steam generator (SG) inspections performed at Virgil C. Summer Nuclear Station (VCSNS), Unit 1. The inspections were performed during refueling outage (RFO) 24.

In Appendix A of Part 50 of Title 10 of the Code of Federal Regulations (10 CFR), General Design Criteria (GDC) 14, 15, 30, 31, and 32, define requirements for the structural and leakage integrity of the RCPB. As part of the RCPB, the SG tubes must also meet the requirements of 10 CFR 50.55a with respect to inspection and repair requirements of the ASME Code. All pressurized water reactors have Technical Specifications (TS) according to 11/9/2020 10:57:49 AM

10 CFR 50.36 that include a SG Program with specific criteria for the structural and leakage integrity, repair, and inspection of SG tubes. VCSNS, Unit 1 TS Section 6.9.1.12 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 performed in accordance with TS Section 6.8.4.k, which requires that a SG Program be established and implemented to ensure SG tube integrity is maintained.

To complete its review of the inspection, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following additional information;

1. The NRC staff has the following questions regarding the secondary side inspections performed on each SG;

a. Please discuss if there were any anomalies noted during the secondary side inspections performed on each SG.

b. Section 3.4, "Foreign Object Wear," of the fall 2018 SG tube inspection report states that two foreign object wear indications were identified in tubes Row 25, Column 72 (R25C72) and R110C77 in SG A, and two foreign object wear indications were identified in tubes R91C88 and R92C87 in SG B. Please discuss whether the foreign objects were still present at the time of the inspection and if they were removed from the SGs.

c. Section 6.0, "Tubes Plugged during the Inspection Outage," of the fall 2018 SG tube inspection report states that a total of 10 tubes were plugged; 3 plugged due to foreign object wear and 7 plugged due to possible loose parts (PLPs). Please confirm whether the PLPs were newly identified during RFO24, how many total PLPs there were in the seven tubes, and describe any additional actions taken to further evaluate these PLPs.

11/9/2020 10:57:49 AM