ML19209D185
| ML19209D185 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/10/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| References | |
| 747A, NUDOCS 7910190510 | |
| Download: ML19209D185 (1) | |
Text
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- 20 October 10, 1979 Mr. James P. O'Reilly, Director Serial No. 747A Office of Inspection & Enforcement PSE&C/SCJ:mac: wang U. S. Nuclear R,egulatory Conrnission Region II Docket No. 50-339 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
On September 10, 1979, a report was made under the provisions of 10CFR50.55(e) concerning the Emergency Diesel Generator Fan Cooling System.
During a review of equipment specifications and the subsequent analysis of local meteorological data, it was discovered that ambient temperature ranges exist which exceed the original design limits of the Fan Cooling System. This necessitates that seasonal blade pitch angle changes be made to insure that the fan drive shaft coupling horsepower limit of 180 H.P. is not exceeded.
However, the Emergency Diesel Generator must be in a secured mode to make the manual blade pitch changes.
To eliminate this time consunrning procedure and the subsequent unavailability of the Emergency Diesel Generators, the manufacturer (Fairbanks Morse) has engineered a modification to the current fan drive shaft coupling that will increase the fan drive shaft torsional load carrying capability from 180 to 230 H.P.
This will allow the Emergency Diesel Generator to operate throughout the year at a fixed blade pitch angle without overloading the fan drive shaft. The modification involves the addition of two bolts to the current four bolt coupling design.
This letter is an interim 30-day report on this subject and a final report will be submitted when the corrective action is complete.
If additional information is required for your review, please notify us.
Very tr y yours,
- [
Sam C.
own, Jr.
Senior Vice Pre dent - Power Station Engineering and Construction cc: Mr. Victor Stello Director Office of Inspec on & Enforcement Mr. Harold R. Denton, Director jjJi}} ob Office of Nuclear Reactor Regulation O
- 7910190 N O??TCrAL Cmv}}