ML24075A187

NRR E-mail Capture - Draft RAIs for Alternative Request RR-5-V2 (L-2023-LLR-0068)

ML24075A187
Person / Time
Site:	Summer
Issue date:	03/15/2024
From:	Ed Miller Plant Licensing Branch II
To:	Gao Y Dominion Energy South Carolina
References
L-2023-LLR-0068
Download: ML24075A187 (4)

Text

From: Ed Miller Sent: Friday, March 15, 2024 10:42 AM To: Yan.Gao@dominionenergy.com

Subject:

Draft RAIs for RR-5-V2 (L-2023-LLR-0068)

Attachments: Summer RR-5-V2 DRAI R2.docx

Mr. Gao, Attached is the NRC staffs draft RAI for the subject request. The questions are being transmitted to you to determine 1) If the questions clearly convey the NRC information needs, 2)

Whether the regulatory basis for the questions are clear, and 3) If the information has already been provided in existing docketed correspondence. Additionally, review of the draft question will allow you to determine what response time you can support. After youve had a chance to review, please let me know if you would like to have a clarification call or public meeting to discuss. Thank you.

Ed Miller (301) 415-2481 Hearing Identifier: NRR_DRMA Email Number: 2431

Mail Envelope Properties (SA1PR09MB74874ECC9F5042BDDAC2CB28E9282)

Subject:

Draft RAIs for RR-5-V2 (L-2023-LLR-0068)

Sent Date: 3/15/2024 10:42:10 AM Received Date: 3/15/2024 10:42:00 AM From: Ed Miller

Created By: Ed.Miller@nrc.gov

Recipients:

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

Tracking Status: None

Post Office: SA1PR09MB7487.namprd09.prod.outlook.com

Files Size Date & Time MESSAGE 637 3/15/2024 10:42:00 AM Summer RR-5-V2 DRAI R2.docx 23816

Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

DRAFT REQUEST FOR ADDITIONAL INFORMATION ALTERNATIVE REQUEST RR-5-V2 VIRGIL C. SUMMER NUCLEAR STATION UNIT 1 DOMINION ENERGY SOUTH CAROLINA, INC.

DOCKET NO. 50-395 EPID L-2023-LLR-0068

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Background===

In a letter dated December 21, 2023 (Agencywide Documents Access and Management System Accession No. ML23361A104), Dominion Energy South Carolina, Inc. (DESC, licensee) submitted requests related to the Fifth Interval Inservice Testing (IST) Program at the Virgil C. Summer Nuclear Station (VCSNS) Unit 1. In Alternative Request RR-5-V2, the licensee proposes to perform testing of specific valves at VCSNS Unit 1 at intervals ranging from every refueling outage to every fourth refueling outage. The licensee submitted Alternative Request RR-5-V2 pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 55a, Codes and standards, paragraph (z)(1), on the basis that the proposed alternative would provide an acceptable level of quality and safety.

Regulatory Requirements The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part, that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) must meet the inservice test requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in paragraphs 10 CFR 50.55a(f)(2) and (3) and that are incorporated by reference in paragraph 10 CFR 50.55a(a)(1)(iv), to the extent practical within the limitations of design, geometry, and materials of construction of the components.

The NRC regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state:

Alternatives to the requirements of paragraphs (b) through (h) of this section or portions thereof may be used when authorized by the Director, Office of Nuclear Reactor Regulation.

A proposed alternative must be submitted and authorized prior to implementation. The applicant or licensee must demonstrate that:

(1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or

(2) Hardship without a compensating increase in quality and safety. Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Request for Additional Information VCSNS Unit 1 Alternative Request RR-5-V2 specifies that the specified interval for each valve would be a function of its performance and would be established in a manner consistent with the containment isolation valve extended test eligibility process guidance under 10 CFR Part 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, Option B. The leakage data provided in Alternative Request RR-5-V2 for the applicable valves show a wide variation in the measured leakage rates over many years. The NRC staff requests the licensee to describe the representative sampling of the subject valves (e.g., plans to obtain test data during outages to support an extended test interval program) within the scope of the request during each refueling outage for leakage testing when implementing Alternative Request RR V2. Please clarify how the historical data of the leakage rates will be used to determine an initial and successive sampling program to ensure that valves with increasing trends do not exceed their leakage limits before their next scheduled test.