ML20094E165
| ML20094E165 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 10/30/1995 |
| From: | Hill W NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737 GL-82-33, NUDOCS 9511070104 | |
| Download: ML20094E165 (2) | |
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Northem States Power Company R 3H Monticello Nuclear Generating Plant 2807 West Hwy 75 Monticello. Minnesota 553G2-9637 October 30,1995 US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 Notification of Two Containment isolation Valves in Non-Comoliance with Licensee Commitment This letter provides notification of a self identified non-compliance to a licensee commitment made in response to Generic Letter 82-33, " Supplement 1 to NUREG-0737 Requirements for Emergency Response Capability".
By [[letter::05000263/LER-1983-025-03, /03L-0:on 831202,RHR Svc Water Sys Pump Declared Inoperable Due to Failure of Check Valve to Seat Properly. Caused by Excessive Disk Stud Thread Wear.Weld Matl Added to Stud & New Threads Machined for Nut|letter dated December 30,1983]], with subject, "NUREG-0737 Supplement 1 - Generic Letter 82-33, Regulatory Guide 1.97 - Application to Emergency Response Facilities", Monticello provided commitments and exceptions for conformance to Regulatory Guide 1.97,
" Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident." By our [[letter::05000263/LER-1983-025-03, /03L-0:on 831202,RHR Svc Water Sys Pump Declared Inoperable Due to Failure of Check Valve to Seat Properly. Caused by Excessive Disk Stud Thread Wear.Weld Matl Added to Stud & New Threads Machined for Nut|December 30,1983 letter]], Monticello provided an exception, with justification, to the Regulatory Guide 1.97 positions for assuring primary containment isolation valve position indication. Monticello stated that Each pnmary containment isolation valve is equipped with a single channelposition indication scheme. However, there are two isolation valves in sedes at each pnmary containment penetration, either of which will accomplish the required isolation.
Therefore, the controlroom operatorcan venfyproperisolation by observing the indication for the redundant valve should the position indication on any valve fail.
Monticello's compliance with Regulatory Guide 1.97 conceming primary containment isolation valve position indication was accepted by the NRC staff by letter dated February 11,1985, with subject, " Emergency Response Capability - Conformance to Reg. Guide 1.97, Rev. 2."
On September 29,1995, as part of the Monticello design basis verification, Monticello Site personnel identified that contrary to the above stated licensee commitment, the power source for position indication for primary containment inboard and outboard isolation valves CV-2790 and CV-2791, Recirculation System Process Sampling, is from the same source. A single failure of the power source will cause a loss of the position indication for both valves. The Recirculation Process Sample containment isolation valves are air operated globe valves that are designed to fail closed on loss of air or electric power to the solenoid. These primary n
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Page 2 containment isolation valves are configured such that one valve is located inside containment and the other outside of containment.
Monticello has taken the following actions to address this commitment non-compliance:
1.
Due to potential industry interest in this non-compliance, Monticello has provided industry notification via the Institute for Nuclear Power Operations (INPO) Nuclear Network.
i 2.
Written instructions have been provided to the Main Control Room operators to -
determine Recirculation System Process Sample containment isolation valve position from the control room via a limit switch continuity test, should the position indication power supply fail.
3.
The Recirculation System Process Sample containment isolation valve position indication power supplies will be modified to establish compliance with our December 30,1983 commitment concaming primary containment isolation valve j
position indication.
1 This letter contains the following new NRC commitment:
The Recirculation System Process Sample containment isolation valve position indication power supplies will be modified to establish compliance with our December 30,1983 commitment stated herein.
Please contact Mary Engen, Sr Licensing Engineer, at (612) 295-1291 if you require further information.
h/'bity
//
William J Hill Plant Manager Monticello Nuclear Generating Plant c:
Regional Administrator-lil, NRC NRR Project Manager, NRC Sr Resident inspector, NRC State of Minnesota, Attn: Kris Sanda 10/30/95 NSP H:\\ DATA \\NRCCORR\\RG1-97CV. DOC