ML18153D301
| ML18153D301 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 04/14/1993 |
| From: | Bowling M VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 93-208, NUDOCS 9304190307 | |
| Download: ML18153D301 (2) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND. VIRGINJ;A 23261 April 14, 1993 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 10 CFR 50.63 STATION BLACKOUT (SBO)
REVISED ALTERNATE AC DESIGN Serial No.
NL&P/GDM Docket Nos.
License Nos.93-208 RO 50-280 50-281 DPR-32 DPR-37 As part of our ongoing design review process, we have recently completed a reassessment of our NRC approved modifications to implement the station blackout rule at Surry Power Station. This reassessment was prompted by the receipt of additional design information associated with the two alternate AC diesels presently on order and completion of a thorough operational review of the station loads required to be powered by the emergency buses in the event of a SBO.
Based on this reevaluation, we have determined that a modified, less complicated design can be implemented to meet the SBO rule while still meeting the existing implementation schedule. The revised design would install only one alternate AC (AAC) diesel generator as opposed to the two AAC diesels currently approved by the NRC. The single diesel will be sized to power the required SBO loads for both units through tie-ins to the 'D' and 'E' transfer buses. This design obviates the need for a dual unit outage or Technical Specification relief since a tie-in to the 'F' transfer bus will no longer be necessary. In addition, we may be able to improve upon the implementation schedule.
The revised design will allow us to realize cost savings by the cancellation of the procurement of one AAC diesel and its associated support systems and mutual use of portions of the SBO diesel building design already being prepared for North Anna. A significant reduction in construction and future operation and maintenance costs would also be realized by this approach.
To ensure both the implementation schedule and the projected cost benefit of the change are maintained, acceptance of the proposed design by the NRC in a timely fashion is necessary. We would therefore like to discuss the modifications with the Staff. as soon as possible. Pursuant to recent discussions between Mr. M. L. Bowling
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of my staff and Mr. H. N. Berkow of the NRC, a meeting has been scheduled for April 21, 1993 to discuss the technical details of the revised design and to address any questions the Staff may have at this time.
If you have any questions or require additional information, please contact us.
Very truly yours,
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M. L. Bowling, Manager Nuclear Licensing and Programs cc:
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station