ML20043F710
| ML20043F710 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/06/1990 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9006180032 | |
| Download: ML20043F710 (2) | |
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BALTIMORE 1
OAS AND ELECTRIC CHARLES CENTER
- P. O. BOX 1476. BALTIMORE, MARYLAND 21203 GroRot C, CattL
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Vict Patsictwt eductsam tNamov (300 aeo-eats June 6,1990 U. S. Nuclear Regulatory Commission Washington, DC 20$$5 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. I & 2; Docket Nos. 50-317 & 50-318 Suonlemental Station Blackout Submittal
REFERENCE:
(a) Letter from Mr. G. C. Creel (BG&E) to NRC Document Control Desk, dated March 30, 1990, same subject l
1 Gentlemen:
This letter provides additional information on the general approach described in the referenced letter. In response to the station blackout rule (10 CFR 50.63), we performed an evaluation as described in Reference (a) that established the coping duration for Calvert Cliffs, as presently ' configured, as eight hours for both units.
As a result of this determination, a decision was made to add two Class IE diesel generators to reduce the required coping duration. The resulting configuration has two diesel generators dedicated to each unit, with the fifth diesel generator acting as a spare.
The fifth diesel generator is a
fully qualified Class IE
- diesel, capable of substituting for any one of the dedicated diesel generators. With all four diesel generators in their normal configuration, the spare diesel generator can act as an alternate AC source. Although the spare diesel can be started in the control room, action must be taken outside the control room to connect it to a safety-related bus.
With this configuration, the required coping duration is one hour for one unit. The other unit does not experience a blackout.
When one of the four dedicated diesels must be removed from service for repair or maintenance, the spare diesel would be removed from service as an alternate AC source I
and connected to the affected safety-related bus, in this configuration, the required coping duration is four_ hours for one unit. The other unit does not experience a blackout. This is the most limiting configuration for the proposed diesel arrangement,
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but is necessary to allow operational flexibility. Accordingly, analyses have been completed to support a coping duration of four hours for either unit.
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9006180032 900606
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Doe: ment Contr:;l Desk J:ne 6,1990 1%ge 2 In addition, since we contemplate that the coping duration requirements will alternate between one and four hours, depending on the status of the spare diesel, our emergency operating procedures will be revised to require difftrent actions based on whether the spare diesel is aligned for alternate AC duty or is dedicated to a single unit as a replacement diesel.
We trust the information provided above has clarified the description of the general approach to stat!on blackout described in the referenced letter. Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours,
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GCC/ PSF / dim cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A.Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC L. E. Nicholson, NRC R.1. McLean, DNR 4