ML20031F932
| ML20031F932 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/16/1981 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8110200568 | |
| Download: ML20031F932 (2) | |
Text
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haclear loanung.Alontntstrator C0mpany General oHices: 1945 West PareaH Road, Jackson, MI 49201 * (517) 788 1606 October 16, 1981 8
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Director, Nuclear Reactor Regulation i
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Att Mr Dennis M Crutchfield, Chief
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Operating Reactors Branch No 5
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US Nuclear Regulatory Commission
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Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POLNT PLANT - SCHEDULE FOR MODIFICATIONS PROPOSED BY PRA Consumers Power Company has initiated efforts to implement modifications proposed in the Big Rock Point Plant Probabilistic Risk Assessment (PRA) transmittal letter dated March 31, 1981. Although final NRC review of the Big Rock Point Plant PRA will not be completed until early 1982 the follcwing activities are in progress:
1.
Emergency Condensor Makeup Modification Make fire water supply valve (VEC-1) to the emergency condensor a DC operated valve actuated by the operator from the control room.
2.
Reactor Depressurization System (RDS) Reliability Podification Implement a procedure change to permit high-pressure recircu-lation using the main feedwater system.
3.
Post Incident System (PIS) Reliability Modification Implement necessary modifications to eight manual valves in the PIS (VFP-1 through VFP-8) such that the valves can only be locked in the correct position.
4.
Primary Coolant System (PCS) Isolation Valve Modification Install a second isolation valve or flange on PCS interfaces which only have a single isolation valve.
5.
Fire Protection Medification Install the alternate shutdown panel.
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PDR oc1081-0010a142
1 Dennis M Crutchfield, Chief 2
Big Rock Point Plant October 16, 1981 6.
Secondary System Instabilities Modifications Improve reliability of main feedwater pumps during load rejections.
(The load rejection modification is estimated to be only marginally cost effective from the point of view of plant risk reduction, but should be extremely cost effective from the plant availiability viewpoint.)
Items 1 through 4 are tentatively scheduled to be completed during the 1982 refueling outage and Items 5 and 6 are schedaled for the 1983 refueling outage. These activities will be carried out as normal facility changes with all appropriate safety reviews (10CFR50.59) completed.
In addition, one other PRA proposed modification has been completed:
1.
Early Enclosure Spray Modification Elimination of 15 minute time delay for containment spray actuation.
Consumers Power intends to continue to make use of the Big Rock Point Plant PRA where appropriate and we are anxious to respond to the formal NRC review of our PRA report.
David P Hoffman Nuclear Licensing Administrator CC Director, Region III, USNRC NRC Resident Inspector-Big Rock Point i
l oc1081-0010a142
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