ML21182A290

7/1/2021 E-mail - Request for Additional Information Alternative Frequency to Supplemental Valve Position Verification Testing Requirements

ML21182A290
Person / Time
Site:	Millstone
Issue date:	07/01/2021
From:	Richard Guzman NRC/NRR/DORL/LPL1
To:	Sinha S Dominion Energy Nuclear Connecticut
Guzman R
References
EPID L-2021-LLR-0018
Download: ML21182A290 (3)

Text

From: Guzman, Richard To: Shayan.Sinha@dominionenergy.com Cc: Danna, James

Subject:

Millstone Power Station, Unit 3 - REQUEST FOR ADDITIONAL INFORMATION Regarding Alternative Frequency to Supplemental Valve Position Verification Testing Requirements (EPID L-2021-LLR-0018)

Date: Thursday, July 01, 2021 11:33:31 AM Mr. Sinha, On June 21, 2021, the U.S. Nuclear Regulatory Commission (NRC) staff sent Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) the subject Request for Additional Information (RAI) as a draft e-mail. The RAI relates to the licensees alternative request dated March 24, 2021 (ADAMS Accession No. ML21084A239), for Millstone Power Station, Unit 3 (MPS3).

On June 29, 2021 the NRC staff and DENC held a conference call to discuss clarifications on the draft RAI. Updated below is the official (final) RAI. As we discussed, please respond to this RAI by August 2, 2021. A publicly available version of this message will be placed in the NRCs official recordkeeping system (ADAMS). Please contact me if you have any questions in regard to this request.

========================================================

REQUEST FOR ADDITIONAL INFORMATION SUPPLEMENTAL VALVE POSITION VERIFICATION TESTING ALTERNATIVE REQUEST DOMINION ENERGY NUCLEAR CONNECTICUT, INC MILLSTONE POWER STATION, UNIT 3 DOCKET NO. 50-423 EPID: L-2021-LLR-001 By letter dated March 24, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21084A239), Dominion Energy Nuclear Connecticut, Inc.

(DENC, the licensee) submitted an alternative request to the U.S. Nuclear Regulatory Commission (NRC) for the use of an alternative to specific requirements in the 2012 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) at Millstone Power Station, Unit 3 (MPS3) for the remainder of the Fourth 10-year Inservice Testing (IST)

Program interval, which ends on December 1, 2028. Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(1), the licensee requested to use the proposed alternative on the basis that the alternative provides an acceptable level of quality and safety.

Applicable Regulation and Guidance The regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, states, in part, that valves that are within the scope of the ASME OM Code must meet the IST requirements set forth in the ASME OM Code; and that valves that are within the scope of the ASME OM Code, but are not classified as ASME Boiler and

Pressure Vessel Code Class 1, 2, or 3, may be satisfied as part of an augmented IST program.

The regulations in 10 CFR 50.55a(z) state, in part, that alternatives to the requirements in paragraphs (b) through (h) of 10 CFR 50.55a may be authorized by the NRC if the licensee demonstrates that: (1) the proposed alternative provides an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. In order for the staff to determine if the proposed alternative may be authorized pursuant to 10 CFR 50.55a(z)(1), the staff requests the licensee provide the following additional information.

ASME OM Code, Subsection ISTC, Inservice Testing of Valves in Water-Cooled Reactor Nuclear Power Plants, paragraph ISTC-3700, Position Verification Testing, as incorporated by reference in 10 CFR 50.55a, states the following:

Valves with remote position indicators shall be observed locally at least once every 2 years to verify that valve operation is accurately indicated. Where practicable, this local observation should be supplemented by other indications such as use of flow meters or other suitable instrumentation to verify obturator position. These observations need not be concurrent.

Where local observation is not possible, other indications shall be used for verification of valve operation.

The NRC regulations in 10 CFR 50.55a(b)(3)(xi), OM Condition: Valve Position Indication, state:

When implementing paragraph ISTC-3700, Position Verification Testing, in the ASME OM Code, 2012 Edition through the latest edition and addenda of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) of this section, licensees shall verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation to provide assurance of proper obturator position for valves with remote position indication within the scope of Subsection ISTC including its mandatory appendices and their verification methods and frequencies.

RAI-1

In its March 24, 2021, submittal, the licensee states that for certain valves at MPS3, 10 CFR Part 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, Type C Local Leak Rate Testing (LLRT) is credited to meet the supplemental position verification closure testing portion of the requirements in ASME OM Code, Subsection ISTC, paragraph ISTC-3700, and 10 CFR 50.55a(b)(3)(xi). The licensee states that it adopted the 10 CFR Part 50, Appendix J, Performance-Based, Option B Program, consistent with Nuclear Energy Institute 94-01, Revision 3-A, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J, for MPS3.

The licensee notes that this program allows LLRT intervals to be extended up to 75 months for valves with a history of satisfactory testing. In its submittal, the licensee proposes an alternative to the ASME OM Code, Subsection ISTC, paragraph ISTC-3700 close position requirements, to perform the valve supplemental position verification at a frequency

consistent with 10 CFR Part 50, Appendix J, Type C testing (LLRT) for MPS3. The NRC staff requests that the licensee describe the activities that provide an accurate verification of the close positions of the applicable valves.