ML25268A108
| ML25268A108 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 09/26/2025 |
| From: | Markley M Plant Licensing Branch II |
| To: | Coleman J Southern Nuclear Operating Co |
| Kalathiveettil, D | |
| References | |
| EPID L-2025-LLR-0014 | |
| Download: ML25268A108 (8) | |
Text
September 26, 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 NO. 1 - AUTHORIZATION OF RELIEF REQUEST RR-V SIXTH INSERVICE TESTING INTERVAL (EPID L-2025-LLR-0014)
Dear Ms. Coleman:
By letter dated January 30, 2025, as supplemented by letter dated May 15, 2025, Southern Nuclear Operating Company (SNC, the licensee) submitted Relief Request RR-V-1 for the Sixth Inservice Testing (IST) interval at the Edwin I. Hatch Nuclear Plant (Hatch), Unit 1, which is scheduled to begin on January 1, 2026.
The licensee requested Relief Request RR-V-1 for Hatch, Unit 1, on the basis that granting relief is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. The U.S. Nuclear Regulatory Commission (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 (f)(6)(i) for the Code of Record Interval that implements 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). The proposed testing provides reasonable assurance that the valves listed in the attached safety evaluation are operationally ready.
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 No. 50-321
Enclosure:
Safety Evaluation cc: Listserv MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2025.09.26 20:13:46 -04'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION AUTHORIZATION OF VALVE RELIEF REQUEST RR-V-1 SIXTH INSERVICE TESTING INTERVAL SOUTHERN NUCLEAR OPERATING COMPANY EDWIN I. HATCH NUCLEAR PLANT, UNIT NO. 1 DOCKET NO. 50-321
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-1 to the U.S. Nuclear Regulatory Commission (NRC, the Commission) requesting relief 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), Unit 1.
The licensee submitted Relief Request RR-V-1 pursuant to 10 CFR 50.55a(f)(6)(i), Impractical IST requirements: Granting of relief, on the basis that compliance with the ASME OM Code requirements is impractical for 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:
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(f)(5)(iii), state:
IST program update: Notification of impractical IST Code requirements. If the licensee has determined that conformance with certain Code requirements is impractical for its facility, the licensee must notify the Commission and submit, as specified in § 50.4, information to support the determination.
The regulations in 10 CFR 55a(f)(6)(i), Impractical IST requirements: Granting of relief, state:
The Commission will evaluate determinations under paragraph (f)(5) of this section that code requirements are impractical. The Commission may grant relief and may impose such alternative requirements as it determines are authorized by law, will not endanger life or property or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the Commission to grant the relief requested by the licensee.
3.0 TECHNICAL EVALUATION
The applicable Code of Record for the Hatch Unit 1, Sixth IST interval is the 2022 Edition of the ASME OM Code. The Hatch, Unit 1, Sixth IST interval is scheduled to begin on January 1, 2026.
3.1 Licensees Relief Request RR-V-1 3.1.1 Applicable ASME OM Code Requirements The requirements in the ASME OM Code, Mandatory Appendix IV, Preservice and Inservice Testing of Active Pneumatically Operated Valve Assemblies in Nuclear Reactor Power Plants, as incorporated by reference in 10 CFR 50.55a, related to Relief Request RR-V-1 are as follows:
Paragraph IV-3420, Stroke Testing, states, in part, that:
b) Stroke testing includes stroke time measurement as follows:
- 1) The limiting value(s) of full-stroke time of each valve shall be specified by the Owner
- 2) The stroke time of all valves shall be measured to, at least, the nearest second.
- 3) Any abnormality or erratic action shall be recorded (see IV-9000), and an evaluation shall be made regarding a need for corrective action.
- 4) Where IV-3410(e) is used to validate valve function, a stroke test shall be performed quarterly c) Stroke testing should be performed prior to performance assessment testing when these tests are scheduled concurrently. This action ensures that the stroke test and its associated trendable parameters are performed under repeatable conditions to the extent practicable.
d) Valve obturator movement shall be determined in accordance with ISTC-3530 e) See IV-7100 for acceptance criteria 3.1.2 Components for Which Relief is Requested Component ID Description ASME Code Class ASME OM Code Category 1C11-F010A Scram Discharge Volume (SDV) Vent Valve 2
B 1C11-F010B SDV Vent Valve 2
B 1C11-F035A SDV Vent Valve 2
B 1C11-F035B SDV Vent Valve 2
B 3.1.3 Licensees Proposed Alternative and Basis In its letter dated January 30, 2025, the licensee states, in part, that:
Verifying that the scram time for each control rod to notch position 06 is 7 seconds provides reasonable assurance that the control rod will insert when required during a [design-basis accident] DBA or transient, thereby completing its shutdown function. This Technical Specifications Surveillance Requirement (SR 3.1.3.4) is performed in conjunction with the control rod scram time testing of SR 3.1.4.1, SR 3.1.4.2, SR 3.1.4.3, and SR 3.1.4.4. The LOGIC SYSTEM FUNTIONAL TEST in LCO 3.3.1.1, Reactor Protection System (RPS)
Instrumentation, and the functional testing of SDV vent and drain valves in
[limiting condition for operation] LCO 3.1.8, Scram Discharge Volume (SDV)
Vent and Drain Valves, overlap this Surveillance to provide complete testing of the assumed safety function. The associated Frequencies are acceptable, considering the more frequent testing performed to demonstrate other aspects of control rod OPERABILITY and operating experience, which shows scram times do not significantly change over an operating cycle.
The valves will be exercised quarterly but not timed. Additionally, the total valve sequence response time will be verified to be less than Technical Specification requirements during each refueling outage when a complete stroke time test is performed. The above proposed relief provides a reasonable assurance of operational readiness since the valves will be exercised quarterly and total valve response time will be tested each refueling outage to Technical Specification requirements. Based on the impracticality of performing testing in accordance with the Code requirements, and in consideration of the burden on SNC if the Code requirements were imposed, this proposed relief should be granted pursuant to 10 CFR 50.55a(f)(6)(i).
By letter dated December 30, 2015 (ML15310A406), a similar relief was granted for Hatch, Unit 1.
3.1.4 Licensees Reason for its Request In its letter dated January 30, 2025, submittal, the licensee states:
Pursuant to 10 CFR 50.55a(f)(6)(i), relief is requested from the requirements of the ASME OM Code, 2022 Edition, Mandatory Appendix IV Subsection IV-3420 which requires the establishment of limiting values of valve stroke time testing and measurement of individual valve stroke time per IV-3420.
This alternative request is a re-submittal of NRC approved 4th and 5th Interval(s)
Relief Request RR-V-1, previously submitted and approved for alternative testing required by ISTC-5131. ISTC-5130 for Pneumatically Operated Valves invokes Mandatory Appendix IV for Active AOVs [air-operated valves] testing requirements. This Relief Request is for relief from Appendix IV, Subsection IV-3420. The requirements of IV-3420 are similar to the original ISTC-5131 requirements in that stroke time testing is to be performed quarterly and the valve is to be timed to the nearest second. The previous NRC Safety Evaluation conclusions for previous IST Intervals for Plant Hatch should also apply to these Scram Discharge Volume Vent and Drain Valves. (See Precedents for SERs
[safety evaluation reports]).
A limiting value of stroke time cannot be specified for the air operated scram discharge volume vent and drain valves and they cannot be individually stroked and timed. In order to prevent water hammer induced damage to the system during a full CRD [control rod drive] scram, plant Technical Specifications require that system valve operation is adjusted so that the outboard vent and drain valves (F035A and B, F037) full close at least five seconds after each respective inboard vent and drain valve (F010A and B, F011). All valves must be fully closed in less than forty-five (45) seconds.
Additionally, the system is adjusted so that the inboard vent and drain valves (F010A and B, F011) start to open at least five seconds after each respective outboard vent and drain valves (F035A and B, F037) upon reset of a full core scram. The valves are not equipped with individual valve control switches and cannot be individually stroke timed. Because of the adjustable nature of the valve control system, individual valve stroke timing would not provide any meaningful information for monitoring valve degradation. System design prevents stroke timing these valves during normal operation without disabling the Reactor Protection System Scram Signal to the valves. Disabling this signal requires the installation of electrical jumpers and the opening of links in energized control circuits which increase the potential for a Reactor Scram.
3.2
NRC Staff Evaluation
The ASME OM Code, Mandatory Appendix IV, Paragraph IV-3420, requires, in part, a limiting value of full stroke time for each valve be specified by the Owner. Monitoring a valve stroke time trend is one of the key parameters for assessing valve condition and overall performance. The scram and discharge volume vent valves listed in this safety evaluation are not designed to be individually actuated.
In its supplemental letter dated May 15, 2025 (ML25135A409), the licensee confirmed that the table providing the list of components within the scope of Relief Request RR-V-1 contained a typographical error. The NRC staff confirmed the appropriate scope of components for the request as part of its review.
For Relief Request RR-V-1, the NRC staff has determined that requiring the applicable valves to be stroke timed individually is impractical and a burden on the licensee because of the extensive modifications that would be required to the system to meet the ASME OM Code requirements. The licensee has proposed to satisfy the technical specification (TS) quarterly surveillance requirement (SR) testing in lieu of meeting the ASME OM Code requirements. The valves are required by TS SR to close within 45 seconds upon receipt of a scram signal. If the TS SR quarterly test cannot meet the 45 second requirement, then an orderly shutdown shall be initiated. The TS SR quarterly surveillance test provides reasonable assurance of operational readiness because changes in valve stroke time will provide an indication of a valve or valve group in a degraded condition. Therefore, the NRC staff finds that the licensee has justified that Relief Request RR-V-1 for Hatch, Unit 1, may be granted in accordance with 10 CFR 50.55a(f)(6)(i).
Based on the above, the NRC staff has determined that Relief Request RR-V-1 may be granted in accordance with 10 CFR 50.55a(f)(6)(i).
The NRC staff notes that the applicable code of record for the Hatch Unit 1, Sixth IST interval, is the 2022 Edition of the ASME OM Code, as incorporated by reference in 10 CFR 50.55a. The Hatch, Unit 1, 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 granting relief request numbered RR-V-1 for Hatch, Unit 1, is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Accordingly, the NRC staff concludes that the licensee has adequately addressed all the regulatory requirements set forth in 10 CFR 50.55a(f)(6)(i). Therefore, pursuant to 10 CFR 50.55a(f)(6)(i), the NRC staff grants RR-V-1 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, Unit 1, 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 relief with other codes of record is not granted.
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.
Principal Contributors:
N. Hansing, NRR T. Scarbrough, NRR G. Bedi, NRR Date: September 26, 2025
- via eConcurrence OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DEX/EMIB/BC NAME DKalathiveettil KZeleznock SBailey DATE 09/24/2025 09/26/2025 07/14/2025 OFFICE NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME MMarkley DKalathiveettil DATE 09/26/2025 09/26/2025