ML23094A272

April 6, 2023 Presubmittal Meeting Presentation - Extension Request for Thermal Relief Valves (EPID: L?2023?LRM-0023)

ML23094A272
Person / Time
Site:	Comanche Peak
Issue date:	04/06/2023
From:	Peters K Vistra Operations Company
To:	Dennis Galvin NRC/NRR/DORL/LPL4
References
EPID L?2023?LRM-0023
Download: ML23094A272 (1)

Text

Pre-Submittal Meeting for:

COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NOS. 50-445 AND 50-446 April 6, 2023 Extension Request for Thermal Relief Valves

Participants

• Comanche Peak

• NRC

• Andrea Lemons, Manager

• Programs and Tactical Engineering *

• Jim Barnette, CPNPP Licensing *

• Tom Crippes, Interim

• Manager Programs

• Engineering

• Neil Jones, IST Engineer

• Eric Lessmann, Design Engineer

• Brian Turnipseed, Valve Team Supervisor

AGENDA

• Description of Thermal Relief Valves and their History

• Current ASME OM Code Requirement and Reason for Extension Request

• Efforts to Obtain Replacement Parts/Valves

• Proposed Alternative

• Questions?

Description of Thermal Relief Valves and Their History

• Ten Thermal Relief Valves which Protect the SSW side of the Unit 1&2 Train A&B CCW/SSW Heat Exchangers and Various ECCS Pump Lube Oil Coolers

• Relief Valve Design Function and Safety Function

• Originally Excluded as Skid-Mounted and Recently Added to IST Program During IST Program Interval Update Project

• No Maintenance or Testing History Since Licensed Plant Operation for HX Relief Valves

• Overdue Testing (20 years since previous test) for Lube Oil Cooler Relief Valves

Current ASME OM Code Requirement and Reason for Extension Request

• ASME OM Code 2004/2006 and 2017 Editions/Addenda Mandatory Appendix I, I-1390 requires testing or replacement of thermal relief valves every 10 years

• Relief Valves installed for 20+ years without actuation could be stuck closed at worst and are likely to leak after actuation at best - requiring rework and potential parts replacements.

• Lonergan Model LCT-11 RVs are obsolete, and we have insufficient critical spare parts to support rework such that testing could result in an extended shutdown.

• Crosby JMAK Model RVs - currently have no spare spindles in stock and we are awaiting Emersons reply to our RFQ.

Efforts to Obtain Replacement Parts/Valves

• Lonergan LCT-11 relief valves are obsolete. Only parts in stock are the base, gasket, and spring. Critical parts including the disk, guide and spindle are not in stock.

• Since the Lonergan valves were vendor specified, they were not included in and do not meet the CPNPP current design specification for relief valves. So, replacement valves could not easily be specified for a vendor to request a quote from; complicating procurement and RAPIDS search for alternate RVs.

• Emerson assisted by locating original Lonergan valve specifications in November 2022 supporting CPNPP to develop valve specifications.

• CPNPP submitted official RFQ in March 2023. Official quote from Emerson expected in June 2023. Valves have 30+ week lead time ARO such that new replacement valves are not expected until January 2024 at best.

Efforts to Obtain Replacement Parts/Valves

• RAPIDS search for alternates for the Lonergan valves identified 4 valves from DC Cook as potential candidates, some require conversion to our set pressure.

• DC Cooks valves lack required N stamp and/or Seismic &

Stress Qualification Design Reports

• Emerson evaluating whether they can make the design reports applicable to the available valves.

• CPNPP evaluating whether we can approve a deviation from our design specification accepting the valves without an N stamp.

• Unless Emerson can confirm applicability of their Design Reports to the available valves, these valves will not be acceptable.

Proposed Alternative

• Overpressure protection is not needed during system operation to support a system safety function. SSW is an open system that is only isolated to remove the system from service.

• As an alternative that provides an acceptable level of quality and safety until replacement valves are installed, ensure heat exchangers/coolers are vented to prevent overpressure when the system is isolated (Shift Manager Clearance - Caution Tag).

• Request approval to extend test/replacement interval until first cold shutdown outage after acceptable replacement relief valves are available.

Questions?