ML19350E618
| ML19350E618 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 06/17/1981 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 12765, GL-81-04, GL-81-4, NUDOCS 8106230355 | |
| Download: ML19350E618 (2) | |
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Jernes W Cooes 00 00)
Mce Presulent - Ivojects, Engsneenng
~N and Constructson coneest offkee: 1945 West ParnsH Road, Jackson, MI 49201
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D u a, i 2 e nN Mr Harold R Denton, Director s
Office of Nuclear
. actor Regulation kW h' r
US Nuclear Regulatory Commission Washington, DC 20555 G;,,
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MIDLAND PROJECT DOCKET NO 50-329, 50-330 EMERGENCY PROCEDURES AND TRAINING FOR STATION BLACK 0UT EVENTS (GENERIC LETTER 81-04)
FILE: 0926.3/0926.4 UFI: 06*10*01/22*0E*02/70*01*05 SERIAL:
12765 By letter dated February 25,1961 (%eric Letter 81-04), the i;RC requested a review of the Midland Plant's procedures and training pertinent to a station blackout event. Seven specific points were suggested for this review though the investigatioa was not to be limited to only them.
To avoid a misunderstanding our interpretation of a station blackout follows.
To get a true total loss of AC power at Midland, me.ltiple independent DC system failures would also have to occar since the instrument. and preferred AC buses are supplied from the batteries through inverters. Since DC system failures have been excluded from station blackout in the past, we do not believe that loss of the instrument and preferred AC buses simultaneous with loss of all other on-site and off-site AC power sources were intended by the staff. Therefore we have interpreted the tet,i " station blackout" to only include loss of all off-site AC poweg and the energency diesel generators.
In the event of a total loss of AC power which would result from the failures of off-site lines and/or breakers in conjuction with the simultaneous loss of all four emergency diesci generators the Midland Plant design provides the capability to remove decay heat for at least two hours without operator action. Decay heat can be removed through the main steam line relief valves with the Reactor Coolant System in natural circulation, supplying feedwater using the AFW System taking suction from the CST. Because preferred instrument AC and DC power would remain available, operators would retain normal indication of plant status and auxiliary feedwater controls.
Operating procedures will be written and operator training will be conducted to assure the operators are adequately prepared to act during a station blackout event which would include the seven points addressed in the generic 7
letter. A loss of off-site power due to effects external to the plant is beyond the direct control of the control room operators. They would work with oc0681-0067a131 f
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the Company area power controller and area operators for the restoration of grid power. An annual requalification including simulator training will be provided for the actions required to mitigate station blackout events.
Therefore, Consumers Power Company believes the intent of Generic Letter 81-04 has been met for the Midland Plant.
a w M. M L
JWC/WJH/cr CC RWHuston, P-24-624 RJCook, NRC Resident Inspector DBMiller, Midland Construction (3) l l
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