Text

Authorization of Alternative Request RR-V-3 - Sixth Inservice Testing Interval
	ML25268A190
Person / Time
Site:	Hatch
Issue date:	09/30/2025
From:	Markley M; Plant Licensing Branch II
To:	Coleman J; Southern Nuclear Operating Co
	Kalathiveettil, D
References
	EPID L-2025-LLR-0016
	Download: ML25268A190 (0)
	v • d • e

September 30, 2025 Ms. Jamie M. Coleman Regulatory Affairs Director Southern Nuclear Operating Co., Inc.

3535 Colonnade Parkway Birmingham, AL 35243

SUBJECT:

EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 - AUTHORIZATION OF ALTERNATIVE REQUEST RR-V SIXTH INSERVICE TESTING INTERVAL (EPID L-2025-LLR-0016)

Dear Ms. Coleman:

By letter dated January 30, 2025, Southern Nuclear Operating Company (SNC, the licensee) submitted Alternative Request RR-V-3 for the Sixth Inservice Testing (IST) interval at the Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2, which is scheduled to begin on January 1, 2026.

The licensee requested Alternative Request RR-V-3 for Hatch, Units 1 and 2, on the basis that the proposed alternative provides an acceptable level of quality and safety for the IST activities for the American Society of Mechanical Engineers (ASME) valves affected. The NRC staff has completed its review and concludes that SNC has adequately addressed the regulatory requirements set forth in Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, Codes and standards, paragraph (z)(1) for this alternative. Therefore, pursuant to 10 CFR 50.55a(z)(1), the NRC staff authorizes the use of this alternative to the 2022 Edition of the ASME Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), as incorporated by reference in 10 CFR 50.55a, for the Code of Record interval, as defined in 10 CFR 50.55a(y), Definitions, that implements the 2022 Edition of the ASME OM Code, for Hatch, Units 1 and 2. Use of this alternative with other Codes of Record is not authorized.

All other ASME OM Code requirements as incorporated by reference in 10 CFR 50.55a for which relief or an alternative was not specifically requested, and granted or authorized (as appropriate), in the subject request remain applicable.

If you have any questions, please contact the Project Manager, Dawnmathews Kalathiveettil at Dawnmathews.Kalathiveettil@nrc.gov or 301-415-5905.

Sincerely, Michael Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-321 and 50-366

Enclosure:

Safety Evaluation cc: Listserv MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2025.09.30 19:31:38 -04'00'

Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION AUTHORIZATION OF VALVE ALTERNATIVE REQUEST RR-V-3 SIXTH INSERVICE TESTING INTERVAL SOUTHERN NUCLEAR OPERATING COMPANY EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-321 AND 50-366

1.0 INTRODUCTION

By letter dated January 30, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25030A363), and supplemented by letter dated May 15, 2025 (ML25135A409), Southern Nuclear Operating Company (SNC, the licensee) submitted RR-V-3 to the U.S. Nuclear Regulatory Commission (NRC) requesting authorization for a proposed alternative for specific affected valves in lieu of certain inservice testing (IST) requirements of the 2022 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), as incorporated by reference in Title 10 of the Code of Federal Regulations (10 CFR),

Section 50.55a, Codes and standards, for the Sixth Inservice Testing (IST) interval at the Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2.

The licensee submitted Alternative Request RR-V-3 pursuant to 10 CFR 50.55a(z)(1),

Acceptable level of quality and safety, on the basis that the proposed alternative will provide an acceptable level of quality and safety for IST activities applied to the specific affected valves within the scope of this request.

2.0 REGULATORY EVALUATION

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 ASME 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 (f)(2) and (3) of this section

[10 CFR 50.55a] and that are incorporated by reference in paragraph (a)(1)(iv) of this section [10 CFR 50.55a], to the extent practical within the limitations of design, geometry, and materials of construction of the components.

The regulations in 10 CFR 50.55a(z), Alternative to codes and standards requirements, state, in part, that alternatives to the requirements of paragraphs (b) through (h) of 10 CFR 50.55a 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.

3.0 TECHNICAL EVALUATION

The applicable Code of Record for the Hatch Units 1 and 2, Sixth IST interval is the 2022 Edition of the ASME OM Code. The Hatch, Units 1 and 2, Sixth IST interval is scheduled to begin on January 1, 2026.

3.1 Licensees Alternative Request RR-V-3 3.1.1 Applicable ASME OM Code Requirements The requirements in the ASME OM Code, Subsection ISTC, Inservice Testing of Valves in Light-Water Reactor Nuclear Power Plants, as incorporated by reference in 10 CFR 50.55a, related to Alternative Request RR-V-3 are as follows:

Paragraph ISTC-3522, Category C Check Valves, states, in part, that:

(a) During operation at power, each check valve shall be exercised or examined in a manner that verifies obturator travel by using the methods in ISTC-5221.

(c) If exercising is not practicable during operation at power and cold shutdown outages, it shall be performed during refueling outages.

Paragraph ISTC-3700, Position Verification Testing, states:

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. Position verification for active MOVs [motor-operated valves] shall be tested in accordance with Division 1, Mandatory Appendix III.

10 CFR 50.55a(b)(3)(xi), OM Condition: Valve Position Indication states, in part:

When implementing paragraph ISTC-3700, Position Verification Testing, in the ASME OM Code, 2012 Edition through the latest edition of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) of this section, licensees must 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.

3.1.2 Components for Which Alternative is Requested The alternative was proposed for the following components:

Component ID Valve Description ASME Code Class ASME OM Code Category 1B21-F015A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015E Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015F Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015G Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015H Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015J Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015K Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015L Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015M Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015N Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015P Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015R Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F015S Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F041 Unit 1 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 1B21-F043A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F043B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F045A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F045B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F047A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F047B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F049A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F049B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F051A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F051B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F051C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F051D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F053A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F053B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F053C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F053D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F055 Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F057 Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059E Unit 1 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 1B21-F059F Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059G Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059H Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059L Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059M Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059N Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059P Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059R Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059S Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059T Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F059U Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B21-F061 Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F003A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F003B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F004A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F004B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F009A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F009B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F009C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F009D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F010A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F010B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F010C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 1B31-F010D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F011A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F011B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F011C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F011D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F012A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F012B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F012C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F012D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F040A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F040B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F040C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1B31-F040D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E21-F018A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E21-F018B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E21-F018C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E41-F024A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E41-F024B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E41-F024C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E41-F024D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E51-F044A Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E51-F044B Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 1E51-F044C Unit 1 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 1E51-F044D Unit 1 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F041 Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F043A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F043B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F045A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F045B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F047A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F047B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F049A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F049B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F051A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F051B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F051C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F051D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F053A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F053B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F053C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F053D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F055 Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F057 Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 2B21-F059D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059E Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059F Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059G Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059H Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059L Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059M Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059N Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059P Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059R Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059S Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059T Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F059U Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F061 Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F070A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F070B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F070C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F070D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F071A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F071B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F071C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F071D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F072A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 2B21-F072B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F072C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F072D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F073A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F073B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F073C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B21-F073D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F003A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F003B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F004A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F004B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F009A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F009B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F009C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F009D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F010A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F010B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F010C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F010D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F011A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F011B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F011C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F011D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C Component ID Valve Description ASME Code Class ASME OM Code Category 2B31-F012A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F012B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F012C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F012D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F040A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F040B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F040C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2B31-F040D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E21-F018A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E21-F018B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E21-F018C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E41-F024A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E41-F024B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E41-F024C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E41-F024D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E51-F044A Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E51-F044B Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E51-F044C Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 2E51-F044D Unit 2 Instrumentation Excess Flow Check Valve 1

A/C 3.1.3 Licensees Proposed Alternative and Basis In its submittal dated January 30, 2025, as supplemented by a letter dated May 15, 2025 (ML25135A409), the licensee states, in part:

Functional testing with verification that flow is checked will be performed per Technical Specification 3.6.1.3.8 during refueling outages. Surveillance Requirement [3.6.1.3.8] allows a representative sample of EFCVs [excessive flow check valves] to be tested every refueling outage, such that each EFCV will be individually tested approximately every ten years. The sample groups are representative of the various plant configurations, models, sizes, and operating environments.

The EFCVs have position indication in the control room. Check valve remote position is excluded from Regulatory Guide 1.97 as a required parameter for evaluating containment isolation. However, the NRC has imposed NRC Condition (b)(3)(xi) for any valves equipped with remote position indication, requiring supplemental position indication. The remote position indication will be verified accurate at the same frequency as the functional test prescribed in Technical Specification Surveillance Requirement 3.6.1.3.8. Although inadvertent actuation of an EFCV during operation is highly unlikely due to the spring poppet design, Plant Hatch monitors the EFCVs indications on a daily basis as part of the Operations routine. Corrective Action documents are initiated for any EFCVs with abnormal position indication displays and repairs are scheduled for the next refueling outage.

Excess flow check valves are provided in each instrument process line that is part of the reactor coolant pressure boundary. The excess flow check valve is designed so that it will not close accidentally during normal power operation, but will close if a rupture of the instrument line occurs downstream of the valve, and can be reopened, when appropriate, after the closure.

As detailed in Unit 1 FSAR Section 5.2.2.5.4 and Unit 2 FSAR Section 6.2.5.3.3, Plant Hatch has incorporated into the design of each instrument source line a 0.25-inch restricting orifice as close to the RPV [reactor pressure vessel] as possible. This is a redundant design feature which, along with the EFCV, will limit leakage to a level where the integrity and functional performance of the secondary containment and its associated air treatment systems (e.g., filters and standby gas treatment system) are maintained. The coolant loss is well within the capabilities of the reactor coolant makeup system, and the potential offsite exposure is substantially below the guidelines of 10 CFR 100.

Additionally, the design and installation of the excess flow check valves at Plant Hatch follow the guidance of Regulatory Guide 1.11.

Testing the subject valves quarterly or during cold shutdown is not practicable, based on plant conditions. These valves have been successfully tested throughout the life of Plant Hatch and they have shown no degradation or other signs of aging.

The technology for testing these valves is simple and has been demonstrated effectively during the operating history of Plant Hatch. The basis for this alternative is that testing a sample of EFCVs each refueling outage provides a level of safety and quality equivalent to that of the Code-required testing.

Excess flow check valves are required to be tested in accordance with ISTC-3522, which requires exercising the check valves nominally every three months to the positions required to perform their safety functions.

ISTC-3522(c) permits deferral of this requirement to every reactor refueling outage. Excess flow check valves are also required to be tested in accordance with ISTC-3700, which requires remote position indication verification at least once every 2 years. The NRC has also imposed NRC Condition 10 CFR 50.55a(b)(3)(xi) on ISTC-3700 requiring supplemental position indication for these valves also.

10 CFR 50 Appendix J testing is only applicable to EFCVs if they perform a containment isolation function. [EFCSs] are not required to close in response to a containment isolation signal and not required to operate under post-LOCA [loss of coolant accident] conditions. As discussed in Reference 2, the functioning of EFCVs is not necessary to remain within 10 CFR 100 limits. Consequently, for purpose of 10 CFR 50 Appendix J, CIV [Containment Isolation Valve] testing, EFCVs do not provide containment isolation function and are exempt from consideration under Appendix J. However, a leak test is performed to verify the closed safety function for these valves.

The testing described above requires removal of the associated instrument or instruments from service. Since these instruments are in use during plant operation, removal of any of these instruments from service may cause a spurious signal, which could result in a plant trip or an unnecessary challenge to safety systems. Additionally, process liquid will be contaminated to some degree, requiring special measures to collect flow from the vented instrument side and also will contribute to an increase in personnel radiation exposure.

Testing on a cold shutdown frequency is impractical considering the large number of valves to be tested and the locations which the test fixtures must be located. Considering the number of valves to be tested and the conditions required for testing, it is also a hardship to test all of these valves during a refueling outage. Improvements in refueling outage schedules have minimized the time that is planned for refueling and testing activities during the outages.

The excess flow check valve is a simple and reliable device. The major components are a poppet and a spring. The spring holds the poppet open under static conditions. The valve will close upon sufficient differential pressure across the poppet.

Functional testing of the valve is accomplished by venting the instrument side of the valve. The resultant increase in flow imposes a differential pressure across the poppet, which compresses the spring and decreases flow through the valve.

Industry experience as documented in GE Nuclear Energy topical report NEDO-32977-A, Excess Flow Check Valve Testing Relaxation, indicates the EFCVs have a very low failure rate. The report indicates similarly that many reported test failures at other plants were related to test methodologies and not actual EFCV failures. In addition, the SER [safety evaluation report] for the report assumed a 5-fold increase in failure rate to account for any potential aging influence and the resultant failure potential over 10 years was still found to not be significant. Test history at Plant Hatch shows very low failure rate and no evidence of common mode failure, which is consistent with the findings of the NEDO report. The EFCVs at Plant Hatch, consistent with the industry, have exhibited a high degree of reliability, availability, and provide an acceptable level of quality and safety.

Plant Hatch Technical Specifications detail what frequency is required to maintain a high degree of reliability and availability and as an alternative will provide an acceptable level of quality and safety. Therefore, Southern Nuclear Co. requests relief pursuant to 10 CFR 50.55a(z)(1) to test excess flow check valves on a representative sample basis at the frequency specified in Plant Hatch Technical Specification Surveillance Requirements (SR) 3.6.1.3.8.

By letter dated December 30, 2015 (ML15310A406), a similar alternative request was authorized for Hatch, Units 1 and 2.

3.1.4 Licensees Reason for its Request In its submittal dated January 30, 2025, submittal, the licensee states, in part, that:

Pursuant to 10 CFR 50.55a(z)(1), relief is requested from the requirements of the ASME OM Code, 2022 Edition, ISTC-3522(a), ISTC-3522(c), ISTC-3700 and NRC Condition 10 CFR 50.55a(b)(3)(xi) for Supplemental Position Indication.

This alternative request is a re-submittal of NRC approved 4th and 5th Interval(s)

Relief Request RR-V-9, previously submitted and approved for testing of Excess Flow Check Valves (EFCV) at Plant Hatch per Technical Specifications. There have been no substantive changes to this alternative or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions for previous IST Intervals for Plant Hatch. (See Precedents for SERs).

3.2

NRC Staff Evaluation

At nuclear power plants, EFCVs are installed on instrument lines to limit the release of fluid in the event of an instrument line break. Examples of EFCV installations include reactor pressure vessel level and pressure instrumentation, main steam line flow instrumentation, recirculation pump suction pressure, and reactor core isolation cooling (RCIC) steam line flow instrumentation. EFCVs are not required to close in response to a containment isolation signal and are not required to operate under post-LOCA conditions.

The ASME OM Code as incorporated by reference in 10 CFR 50.55a requires EFCVs to be tested in accordance with Subsection ISTC, paragraph ISTC-3510, which states in part that Active Category A, Category B, and Category C check valves shall be exercised nominally every 3 months. The ASME OM Code recognizes that some valves cannot be tested at this frequency. Deferral of this requirement is allowed by paragraph ISTC-3522(c), which states If exercising is not practical during operation at power and cold shutdowns, it shall be performed during refueling outages.

The EFCVs listed in this safety evaluation cannot be exercised during normal operation because closing these valves would isolate instrumentation required for power operation. These valves can only be tested during a refueling outage. The licensee has proposed an alternative to the ASME OM Code required test interval. The proposed alternative revises the surveillance frequency by allowing a representative sample of EFCVs to be tested every refueling outage.

The representative sample is based on an approximately equal number of EFCVs being tested each refueling outage such that each individual valve is tested approximately every 10 years.

As noted in the licensees Technical Specifications (TS) Surveillance Requirements, the TS surveillance frequency is governed by the Surveillance Frequency Control Program (SFCP).

Changes to the frequencies in the SFCP shall be made in accordance with NEI 04-10, Risk Informed Method for Control of Surveillance Frequencies, Revision 1. The NRC staff reviewed NEI 04-10 (Revision 1) and issued its evaluation on September 19, 2007 (ML072570267). In its evaluation, the NRC staff found that the methodology is acceptable, with conditions, for licensees to amend their TS to establish an SFCP. In a letter dated May 15, 2025 (ML25135A409), the licensee confirmed that a representative sample of EFCVs on a 24-month frequency in response to an NRC staff request for additional information.

The licensees justification for Alternative Request RR-V-3 is based on GE Topical Report NEDO-32977-A, Excess Flow Check Valve Testing Relaxation, dated June 2000. The topical report provided (1) an estimate of steam release frequency (into the reactor building) due to a break in an instrument line concurrent with an EFCV failure to close, and (2) an assessment of the radiological consequences of such a release. The NRC staff reviewed the GE topical report and issued its evaluation on March 14, 2000 (ML003691722). In its evaluation, the NRC staff concluded that the test interval could be extended up to a maximum of 10 years. In conjunction with this conclusion, the NRC staff noted that each licensee that adopts the relaxed test interval program for EFCVs must have a failure feedback mechanism and corrective action program (CAP) to ensure EFCV performance continues to be bounded by the topical report results. Also, each licensee is required to perform a plant-specific radiological dose assessment, EFCV failure analysis, and release frequency analysis to confirm that they are bounded by the generic analyses of the topical report.

In response to an NRC staff request for additional information, the licensee provided additional information regarding the elements required to continue to be bounded by the GE Topical Report results by letter dated May 15, 2025 (ML25135A409). Specifically, the licensee discussed the SFCP basis document, which provides a failure feedback mechanism that evaluates failures to determine if additional testing is needed to ensure overall reliability. EFCV failures are documented in the CAP as surveillance test failures, and evaluated and corrected as part of the mechanism. In the same letter, the licensee confirmed a typo on page 10 of its submittal and the erroneous omission of four EFCVs from the table. The NRC staffs review reflects these corrections. Additionally, an orifice is installed upstream of the EFCVs to limit reactor water leakage in the event of rupture. The orifice limits leakage to a level where the integrity and functional performance of secondary containment and associated air treatment systems are maintained.

In summary, the NRC staff reviewed the licensees proposal in Alternative Request RR-V-3 for its applicability to GE Topical Report NEDO-32977-A and conformance with the NRC staffs guidance regarding radiological dose assessment, EFCV failure rate and release frequency, and the proposed failure feedback mechanism and CAP at Hatch. Based on its evaluation, the NRC staff has determined that the radiological consequences of an EFCV failure are sufficiently low and acceptable, and that the alternative testing in conjunction with the CAP and the SFCP provides a high degree of valve reliability and operability. Based on the above, the NRC staff has determined that Alternative Request RR-V-3 may be authorized pursuant to 10 CFR 50.55a(z)(1) on the basis that the proposed alternative provides an acceptable level of quality and safety for the EFCVs within the scope of the request at Hatch.

The NRC staff notes that the applicable code of record for the Hatch Units 1 and 2, Sixth IST interval, is the 2022 Edition of the ASME OM Code, as incorporated by reference in 10 CFR 50.55a. The Hatch Units 1 and 2, Sixth IST interval, is scheduled to begin on January 1, 2026.

The ASME OM Code (2022 Edition), Subsection ISTA, General Requirements, paragraph ISTA-3120, Inservice Examination and Test Interval, as incorporated by reference in 10 CFR 50.55a, requires that licensees implement 10-year intervals for their IST programs. Although not requested, the NRC regulations in 10 CFR 50.55a allow licensees to implement the same ASME OM Code as their Code of Record for two consecutive IST program intervals.

4.0 CONCLUSION

As set forth above, the NRC staff determined that proposed alternative numbered RR-V-3 for Hatch, Units 1 and 2, provides an acceptable level of quality and safety for IST activities for the specific affected valves within the scope of the request. Accordingly, the NRC staff concludes that the licensee has adequately addressed all the regulatory requirements set forth in 10 CFR 50.55a(z)(1) for this proposed alternative. Therefore, pursuant to 10 CFR 50.55a(z)(1), the NRC staff authorizes RR-V-3 for the Sixth IST Interval for the specified valves within the scope of the request in lieu of the applicable IST requirements in the 2022 Edition of the ASME OM Code, as incorporated by reference in 10 CFR 50.55a, for Hatch, Units 1 and 2, for the Code of Record interval, as defined in 10 CFR 50.55a(y), Definitions, that implements the 2022 Edition of the ASME OM Code. Use of this alternative with other codes of record is not authorized.