ML20091L314
| ML20091L314 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/21/1995 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 95-329, NUDOCS 9508290127 | |
| Download: ML20091L314 (2) | |
Text
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VIltOINIA ELucTHIC AND Powan COMI%NY Ricunown,vinorwrA caes:
C August 21, 1995 U.S. Nuclear Regulatory Commission Serial No.95-329 Attention: Document Control Desk NL&P/EJW R0 l
Washington, D.C. 20555 Decket No.
50-338 50-339 License No.
NPF-4 NPF-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 1
STATION BLACKOUT DIESEL OPERABLE in response to your letter dated August 7,1992, notification is hereby provided that the North Anna Station Blackout (SBO) diesel has been ir.stalied, tested, and declared operational effective May 26,1995. Final tie-ins with the Unit 2 buses were completed during the recent Unit 2 refueling / steam generator replacement outage. The SBO diesel allows North Anna Power Station to withstand and recover from a station blackout for a four hour period as approved in the Supplemental Safety Evaluation dated June 8,1992.
Certain SBO-related tasks (i.e., procedure changes, equipment improvements identified during the installation / testing process, and training additional operators) still require completion.
However, these tasks neither affect the operability nor the reliability of the alternate AC power source (i.e., SBO diesel and its associated equipment).
i Additionally, particular features of the SBO diesel's design (an automatic load sequencing feature and a remote control feature) and associated procedural contingencies (procedural activities to open control room instrument doors) were reported as part of a preliminary design in our correspondence dated April 30,1991 (Serial Number 91-242).
Both the design features and associated procedural measures were revised during the design / testing process. An auto load sequencing feature, to load the SBO diesel when feeding the emergency bus, was rejected in favor of maintaining consistency with Westinghouse Owner's Group procedural guidance i
related to manually loading the SBO diesel. A remote control feature for the diesel's controls was not included in the final design in favor of more cost effective local SBO diesel controls. And, a procedural contingency to open control room safe shutdown instrumentation cabinets within 30 minutes in the event of having no ventilation available was rejected since SBO diesel test results have demonstrated adequate restoration of the Heating, Ventilation and Air Conditioning System. These design and procedural revisions in no way reduce the station's capability to cornply with NRC requirements.
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If yoU)1 ave any questions concoming this information, please contact us.
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Very truly yours, b6 tw chc 4-ames P. O'Hanlon Senior Vice President-Nuclear oc:
' U.S. Nuclear Regulatory Commission Region 11 l
101 Marietta Street, N.W.
. Suite 2900 Atlanta, Georgia 30323 Mr. R. D. McWhorter NRC Senior Resident inspector North Anna Power Station m
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