ML18153D402
| ML18153D402 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/28/1993 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 93-292A, NUDOCS 9308050230 | |
| Download: ML18153D402 (2) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 July 28, 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 STATION BLACKOUT (10 CFR 50.63)
CONTROL OF THE AAC POWER SOURCE Serial No.
NL&P/GDM Docket Nos.
License Nos.
93-292A R1 50-280 50-281 DPR-32 DPR-37 Virginia Electric and Power Company has reviewed the NRC staff's supplemental safety evaluation (SSE) provided in your letter dated June 25, 1993.
The SSE approved our May 10, 1993 proposal (Serial No.92-292) to meet the requirements of the station blackout rule with one alternate AC (AAC) diesel generator in lieu of the two AAC diesels previously approved. Although we are in agreement with the conclusions of the Staff's evaluation, we would like to clarify a statement made in Section 2.2, Alternate AC Power Source, of the SSE and note a minor change in design from that previously proposed.
Section 2.2 of the SSE states that, "The AAC power source can be manually started from the control room and also from the AAC building." In clarification, the AAC source can be started from the AAC building, but it cannot be started from the control room.
The AAC diesel generator will auto-start on loss of reserve power and will power AAC auxiliary equipment until aligned by the control room operator to transfer buses "D" and "E" as required. The design now requires the operator to energize the transfer buses manually from the control room.
This design feature was incorporated to provide additional assurance that the AAC diesel will not be automatically aligned to an already energized bus. Operator actions within the control room are then required to restore power to one emergency bus in each unit and to operate selected SBO loads for each unit after energizing the appropriate transfer bus(es).
If you have any questions or require additional information, please contact us.
J~
W. L. Stewart Senior Vice President - Nuclear
-~ ID
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