ML25029A203
| ML25029A203 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/29/2025 |
| From: | Mclatchie H Plant Licensing Branch IV |
| To: | |
| Lee, Samson | |
| References | |
| EPID L-2024-LLR-0079 | |
| Download: ML25029A203 (3) | |
Text
PUBLIC MEETING DISCUSSION TOPICS COMANCHE PEAK 1 - RELIEF REQUEST RV-1A - 2ND EXTENSION REQUEST FOR THERMAL RELIEF VALVES (CP-202400460)
VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK, UNIT 1 DOCKET NO. 05000445
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Background===
On December 11, 2024, Vistra Operations Company, LLC, submitted Alternative Request RV-1A (Agencywide Documents Access and Management System (ADAMS) Accession No ML24346A143) to the U.S. Nuclear Regulatory Commission (NRC) for authorization to perform alternative inservice testing (IST) activities for certain valves at Comanche Peak Nuclear Power Plant, Unit 1, in lieu of specific IST requirements in the 2017 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 thermal relief valves 1SW-0442 and 1SW-0443 in the Station Service Water (SSW) system which provide overpressure protection for the SSW side of the Component Cooling Water Heat Exchangers in Comanche Peak, Unit 1, the licensee propose to extend the requirement to test or replace these two valves specified in ASME OM Code, Mandatory Appendix I, Inservice Testing of Pressure Relief Devices in Water-Cooled Reactor Nuclear Power Plants, paragraph I-1390, Test Frequency, Classes 2 and 3 Pressure Relief Devices That Are Used for Thermal Relief Application, due to a hardship without a compensating increase in quality and safety under 10 CFR 50.55a(z)(2). In that replacement parts or valves to support rework or replacement of these two valves cannot be procured at this time, the licensee proposes in Alternative Request RV-1A to rework/replace the two valves no later than Refueling Outage 1RF25 in the fall of 2026 for Comanche Peak, Unit 1.
Regulatory Basis 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.
Topic 1 Alternative Request RV-1A indicates that suitable replacement parts or valves to support rework or replacement of thermal relief valves 1SW-0442 and 1SW-0443 cannot be procured by Refueling Outage (RFO) 1RF24 (spring 2025) at Comanche Peak, Unit 1. Therefore, the licensee proposes to rework/replace these two thermal relief valves no later than RFO 1RF25 in the fall of 2026 at Comanche Peak, Unit 1. Until the valve rework/replacement, the licensee states that Shift Manager Caution Tags will be placed on the heat exchanger isolation valves and vent valves requiring the heat exchangers to be vented upon isolation and to remain vented until the heat exchanger is no longer isolated from the safe shutdown impoundment. The licensee is requested to discuss its plans for training to alert plant field personnel that the vent valve must be open when the heat exchanger is isolated in addition to the placement of caution tags.
Topic 2 In Alternative Request RV-1A, the licensee proposes to rework/replace the thermal relief valves 1SW-0442 and 1SW-0443 in Comanche Peak, Unit 1, no later than RFO 1RF25 in the fall of 2026. In Alternative Request RV-1A, the licensee states that replacement valves are scheduled to be delivered in January 2026. The licensee is requested to discuss its plans for replacement of these two thermal relief valves if a sufficient duration outage occurs prior to the fall 2026 RFO at Comanche Peak, Unit 1.
Topic 3 In a safety evaluation dated July 27, 2023 (ML23198A321), the NRC staff authorized Alternative Request RV-1 to extend the testing/replacement interval requirement in the ASME OM Code, Appendix I, paragraph I-1390, for several thermal relief valves at Comanche Peak, Units 1 and
- 2. The two thermal relief valves within the scope of Alternative Request RV-1A were also within the scope of Alternative Request RV-1. The licensee is requested to discuss the total duration of the extension of the ASME OM Code testing or replacement interval requirement for these two thermal relief valves, and the confidence in the capability of these valves to perform their safety function over the total duration of the interval extension.
Topic 4 In its submittal dated December 11, 2024, Section Description of Basis for Use, the licensee states in part:
In total, 54 relief valves were found to have been incorrectly excluded from the IST Program.
Many of the valves were tested or replaced within the OM Code required 10-year interval under the Preventative Maintenance Program. In the time since approval of RV-1 (EPID: L-2023-LLR-0019), 18 of the 20 valves which were not in compliance with I-1390 have been tested or replaced to restore code compliance. However, as of December 4, 2024, two valves are not in compliance with the OM Code interval plus the 6-months grace allowed by Code Case OMN-20 and are not expected to be restored to compliance by the expiration of RV-1 at the end of Spring 2025.
The licensee is requested to discuss whether the remaining of the total 54 thermal relief valves in the original request have been restored to compliance with the ASME OM Code as incorporated by reference in 10 CFR 50.55a.
In the above paragraph, the licensee states that Alternative Request RV-1 included 20 relief valves. However, it appears that Alternative Request RV-1 included 19 relief valves. The licensee is requested to clarify this difference.
Topic 5 In Alternative Request RV-1A, the licensee proposed an additional extension of the testing/replacement interval for thermal relief valves 1SW-0442 and 1SW-0443 to no later than the fall of 2026. The licensee is requested to discuss (1) any issue with or repair of these valves from April 2023 to until the present, and (2) the plan if these valves do not perform their required function during the requested extension until the fall of 2026.