ML25209A518
| ML25209A518 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/04/2025 |
| From: | V Sreenivas Plant Licensing Branch 1 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Kim, J | |
| References | |
| EPID L-2024-LLR-0078 | |
| Download: ML25209A518 (9) | |
Text
August 4, 2025 Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Nuclear Constellation 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
R. E. GINNA NUCLEAR POWER PLANT - ALTERNATIVE REQUEST ASSOCIATED WITH INSERVICE TESTING OF LOOP B LETDOWN RELIEF VALVE - VR-04 (EPID: L-2024-LLR-0078)
Dear Mr. Rhoades:
By letter dated November 27, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24332A090), supplemented by email dated March 10, 2025 (ML25076A379), Constellation Energy Generation, LLC (the licensee) submitted proposed Alternative Request VR-04 to the U.S. Nuclear Regulatory Commission (NRC) for an alternative to specific inservice testing (IST) 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) for Loop B Letdown relief valve RV-203 at R. E. Ginna Nuclear Power Plant (Ginna).
Specifically, pursuant to subparagraph (2) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, to Title 10 of the Code of Federal Regulations (10 CFR), the licensee requested a one-time extension of the IST testing interval for the Loop B Letdown relief valve RV-203 at Ginna, on the basis that compliance with certain ASME OM Code requirements, at this time, would present an undue hardship without a compensating increase in the level of quality or safety.
The NRC staff has completed its review of the submittal and concludes that the licensee had adequately addressed all of the regulatory requirements set forth in 10 CFR50.55a(z)(2).
Therefore, the NRC staff authorizes a one-time extension of the IST testing interval for the RV-203 relief valve until repair and replacement parts are available, but no later than the Ginna refueling outage in the spring of 2026. The one-time extension of the IST test interval for the subject RV-203 relief valve is during the sixth 10-year IST Program.
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 me at 301-415-2597 or via email at V.Sreenivas@nrc.gov.
Sincerely,
/RA/
V. Sreenivas, Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-244
Enclosure:
Safety Evaluation cc: Listserv
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST VR-04 SIXTH 10-YEAR INSERVICE TESTING PROGRAM INTERVAL CONSTELLATION ENERGY GENERATION, LLC R. E. GINNA NUCLEAR POWER PLANT DOCKET NUMBER 50-244 EPID: L-2024-LLR-0078
1.0 INTRODUCTION
By letter dated November 27, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24332A090), supplemented by email dated March 10, 2025 (ML25076A379), Constellation Energy Generation, LLC (the licensee) submitted proposed Alternative Request VR-04 to the U.S. Nuclear Regulatory Commission (NRC) for an alternative to specific inservice testing (IST) 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) for Loop B Letdown relief valve RV-203 at R. E. Ginna Nuclear Power Plant (Ginna).
Specifically, pursuant to subparagraph (2) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, to Title 10 of the Code of Federal Regulations (10 CFR), the licensee requested a one-time extension of the IST testing interval for the Loop B Letdown relief valve RV-203 at Ginna, on the basis that compliance with certain ASME OM Code requirements, at this time, would present an undue hardship without a compensating increase in the level of quality or safety.
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 IST 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 10 CFR 50.55a(f)(2) and (3) and that are incorporated by reference in 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 that alternatives to the requirements of 10 CFR 50.55a(b) through (h) 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
3.1 Licensees Alternative Request Applicable Code Edition The applicable Code of Record for the Sixth 10-Year IST Program interval at Ginna is the 2012 Edition of ASME OM Code, as incorporated by reference in 10 CFR 50.55a.
The Sixth 10-Year IST Program interval at Ginna, began on January 1, 2020, and is scheduled to end on December 31, 2029.
ASME Code Components Affected Table 1 lists the Loop B Letdown relief valve at Ginna for which this alternative is being requested.
Table 1 Component ID Description ASME Code Class OM Category 203 Loop B Letdown to Non-Regenerative Heat Exchanger Relief Valve to Pressurizer Relief Tank 2
C Note 1: Category C: valves that are self-actuating in response to some system characteristic, such as pressure (relief valves) or flow direction (check valves) for fulfillment of the required function(s) (
Reference:
ASME OM Code, Subsection ISTC, subparagraph ISTC-1300(c)).
Applicable Code Requirements The IST requirements in the ASME OM Code, as incorporated by reference in 10 CFR 50.55a, related to this alternative request are as follows:
ASME OM Code, Division 1, Mandatory Appendix I, Inservice Testing of Pressure Relief Devices in Light-Water Rector Nuclear Power Plants, Paragraph I-1350, Test Frequency, Class 2 and 3 Pressure Relief Valves, states:
(a) 10-Yr Test Interval. Classes 2 and 3 pressure relief valves, with the exception of PWR main steam safety valves, shall be tested every 10 yr
[years], starting with initial electric power generation. No maximum limit is specified for the number of valves to be tested during any single plant operating cycle; however, a minimum of 20% of the valves from each valve group shall be tested within any 48-mo [month] interval. This 20% shall consist of valves that have not been tested during the current 10-yr test interval, if they exist.
The test interval for any installed valve shall not exceed 10 yr. The 10-yr test interval shall begin from the date of the as-left set pressure test for each valve.
PWR main steam safety valves shall be tested in accordance with para.
I-1320.
(b) Replacement With Pretested Valve states: The Owner may satisfy testing requirements by installing pretested valves to replace valves that have been in service, provided that (1) for replacement of a partial complement of valves, the valves removed from service shall be tested within 3 mo [months] of removal from the system or before resumption of electric power generation, whichever is later or (2) for replacement of a full complement of valves, the valves removed from service shall be tested within 12 mo [months] of removal from the system Licensees Proposed Alternative The licensee proposed Alternative Request VR-04 pursuant to 10 CFR 50.55a(z)(2) for a one-time extension to the current test interval to allow replacement of RV-203 with a rebuilt and a pre-tested spare valve installed during the spring 2026 refueling outage (G1R46).
Licensees Basis for Use A review back to 2009 of the currently installed valve RV-203, serial number 50998, indicates that all As-Found testing was satisfactory (SAT).
Date Serial Number of Valve RV-203 As-Found Test Result 2018 50998 SAT 2015 50998 SAT 2009 50998 SAT Licensees Reason for Request Pursuant to 10 CFR 50.55a(z)(2), the licensee proposed an alternative to the requirement of ASME OM CodeI-1350(a). The basis of the request is that compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
RV-203 is a group of 1 (i.e., the only relief valve in the group). Replacement of RV-203 requires the plant to be shutdown. Therefore, RV-203 is normally replaced with a pre-tested spare every 3 years to align with refueling outages and meet the ASME OM Code requirement in Mandatory Appendix I, Subparagraph I-1350(a), of 48 months. The currently installed relief valve, serial number 50998, had been installed during Ginnas 2021 refueling outage, and was scheduled for replacement during Ginnas 2024 refueling outage. However, the spare valve failed its pre-installation testing. The spare valve had tested satisfactory when removed from service in 2021 and was returned to inventory without in-body repairs. After failing the pre-installation test in 2024, parts for repair were obtained but were deemed insufficient. The reinstallation of the valve without these parts would have presented undue risks for boric acid leaks.
Further, the additional necessary parts for repairing the valve were not readily available and the associated delay would cause a significant impact to the duration of the refueling outage.
With no replacement valve readily available, the licensee evaluated the currently installed relief valve to determine if it could be left in service. Based on the valves consistent and satisfactory test history, the licensee left the currently installed relief valve in service.
This valve cannot be replaced on-line as RV-203 relieves to the Pressurizer Relief Tank (PRT). The Power Operated Relief Valves and Pressurizer Safety Valves also relieve the PRT making full energy isolation not achievable.
Based on the pre-service test date of September 22, 2021, for the currently installed relief valve, and using Code Case OMN-20, Inservice Test Frequency, which permits a 6-month grace period for test frequencies that are greater than or equal to 2 years, RV-203 will exceed the Mandatory Appendix I, paragraph I-1350, 48-month requirement on March 22, 2026, which is before the scheduled start of the spring 2026 Ginna refueling outage (G1R46). Compliance with Mandatory Appendix I, subparagraph I-1350(a) would cause a hardship or unusual difficulty without a compensating increase in the level of quality or safety due to the need to perform a mid-cycle shutdown in order to perform the required testing.
Duration of Proposed Alternative The duration of proposed Alternative Request VR-04 is until the end of the G1R46 refueling outage in March 2026. This would provide an adequate window of opportunity to obtain parts, rebuild the spare relief valve, and install the spare during Ginnas scheduled 2026 refueling outage.
3.2
NRC Staff Evaluation
ASME OM Code, Mandatory Appendix I, subparagraph I-1350(a), requires that that Class 2 and 3 relief valves shall be tested every 10 years. In addition, a minimum of 20 percent of the valves in a group shall be tested within any 48-month interval.
In Alternative Request VR-04, submitted on November 27, 2024, the licensee proposed a one-time extension of the IST interval of relief valve RV-203 from the refueling outage in 2024 to the refueling outage in the spring of 2026. The valve RV-203 is a Loop B letdown relief valve, which provides overpressure protection for the Class 2 Chemical Volume Control System (CVCS) letdown piping, the Residual Heat Removal (RHR) low head safety injection/shutdown cooling header, and the letdown line containment penetration at Ginna.
In the alternative request, the licensee stated that RV-203 is a group of one (i.e., the only relief valve in the group) and is normally replaced with a pre-tested spare valve every 3 years to align with the refueling outages to meet the requirements in subparagraph I-1350(a) of 48 months. Further, the licensee stated the replacement of RV-203 requires the plant to be shutdown. The current installed relief valve, serial number 50998, had been installed during Ginnas fall 2021 refueling outage and was scheduled for replacement during Ginnas fall 2024 refueling outage. However, the spare valve failed its pre-installation testing. Further, the additional necessary parts for repairing the valve were not readily available and the associated delay would have had a significant impact on the duration of the 2024 refueling outage at Ginna. Based on these factors, the licensee submitted the proposed alternative under the hardship provisions of 10 CFR 50.55a(z)(2).
The licensees submittals dated November 27, 2024, and March 10, 2025, summarized the history of the test results for the RV-203 valve from 2009 through 2018. No deficiencies or adverse trends were identified that might have reflected degraded performance of the RV-203 valve. Further, no maintenance work orders were open for the RV-203 valve.
Based on its review, the NRC staff has determined that there is reasonable assurance that the RV-203 valve will continue to be capable of performing its design function during the requested IST test interval extension. The NRC staff finds that compliance with the specified IST requirements for the RV-203 relief valve during the duration of the requested alternative would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Also, the test and performance history for the relief valve RV-203 provides reasonable assurance of its operational readiness during the time period of the alternative request. Therefore, the NRC staff finds that the proposed alternative meets the requirements of 10 CFR 50.55a(z)(2).
4.0 CONCLUSION
As set forth above, the NRC staff has determined that Alternative Request VR-04 submitted by the licensee on November 27, 2024, and supplemented by email on March 10, 2025, provides adequate justification that compliance with the applicable ASME OM Code test requirements for the RV-203 relief valve at Ginna at this time would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The NRC staff also finds that the testing and performance experience of the RV-203 relief valve described by the licensee in its request provides reasonable assurance that the RV-203 relief valve will be operationally ready to perform its safety function for the duration of the request. Accordingly, the NRC staff concludes that the licensee had adequately addressed all of the regulatory requirements set forth in 10 CFR50.55a(z)(2). Therefore, the NRC staff authorizes a one-time extension of the IST testing interval for the RV-203 relief valve until repair and replacement parts are available, but no later than the Ginna refueling outage in the spring of 2026. The NRC staff notes that the one-time extension of the IST test interval for the subject RV-203 relief valve is during the Sixth 10-Year IST Program.
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: G. Bedi T. Scarbrough Date: August 4, 2025
ML25209A518 *by memorandum dated 7/24/2025 **by eConcurrence OFFICE NRR/DORL/LPL1/PM**
NRR/DORL/LPL1/LA**
NRR/DEX/EMIB/BC*
NAME VSreenivas KEntz TScarbrough (A)
DATE 7/25/2025 7/30/2025 7/24/2025 OFFICE NRR/DORL/LPL1/BC**
NRR/DORL/LPL1/PM**
NAME HGonzález VSreenivas DATE 8/4/2025 8/4/2025