ML20101R122
| ML20101R122 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/08/1992 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEIN-92-018, IEIN-92-18, NSD920730, NUDOCS 9207150233 | |
| Download: ML20101R122 (2) | |
Text
{{#Wiki_filter:- _ _ _ GENE W OUICE P O BOK 4M. COLUMBUS. NEBRASKA (#t044W Nebraska Public Power District "an&"#C**
- -==uum m em m e m m m m = w, m m r we m. m m m m. m m m.y-mm NSD920730 July 8, 1992 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Subject' Notification of Plans to Restore Alternate Shutdown Capability Cooper Nuclear Station NRC Docket No. 50-298, DPR 46 Gentlemen:
This letter is being submitted pursuant to the requirements of Cooper Nuclear Station (CNS) Technical Specification 3.2.I,2. The Limiting Condition for Operation for this specification was entered when the Altertiate Shutdown (ASD) capability f or CNS was declared inoperable on June 11, 1992, following a review -of NRC Information Notice 92-18, " Potential for les of Remote Shutdown capability During a Control Roorn Fire." The review discovered that the possibility caints, in certain fire scenarios, for control circuit faults to occur in 19 motor operated valves p" lor to the transfer of their control to the ASD panel. These control circuit faults could cause the bypass of the inetor operator position limi and torque cutout switches and, because of the absence of thermal overload protection, could permit possible damage to the rnotr r operated valve thereby tendering the ASD capability inoperable. CNS Technical Specification 3.2,1.2 does not require a plant shutdown upon loss of ASD capability but rather restoration of the equipment to operable status within 30 days or notification of the NRC providing the District's plans to restere the ASD capability. The District is currently reviewing the various corrective measures that will provide permanent resolution of this ASD deficiency, The District is committed to complete any necessary valve circuit modifications or other permanent corrective actions prior to startup from the Spring 1993 refueling outage presently scheduled to begin in March 1993, I In the interim, the District has initiaced several compensatory measures that include: Briefing of appropriate plant and control room personnel on the potential failure mechanisms and mitigating actions. Implementing temporary procedure changes to expedite implementation of mitigating actions and corre nive measures to prevent damage to motor operated valve circuits. ~The District plans to continua plant operation with these interim measures ir place until the Spring 1993 refueling outage during 'shich final corrective actions will be completed. Those interim measures, in conjunction with the plant's existing fire deteccion and suppression capabilities required by -{f / h J 9207150233 920708 PDR ADDOK 05000298 p PDR i Nb NNbb bb f h,bhk h b kh[h,h h - = _ 1 z my 7 m
k. s NSD920730 Page 2 of 2 ) Technical Specit?. cations und the extremely low probability of a fire occurrin6 in those areas that would cause a loss of ASD capability, will maintain the required level of safety for continued operation of CNS through March 1993. If yots have any questions, please call. Sing / rely W. llorn - Nu ear Power Group Manager / dis cc: U.S. Nuclear Regulatory; Commission Region IV Arlington. Texas iAC Senior Resident Inspector Cooper-Nuclear Station I. - _, = f k L ._,...}}