ML19211B728

Suppl to 790910 Deficiency Rept Re Design Inadequacy in Emergency Diesel Generator Fan Cooling Sys.Ambient Temp Ranges Exceed Capability of Fan Cooling Sys.Alternate Solutions Under Evaluation

ML19211B728
Person / Time
Site:	North Anna
Issue date:	09/14/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML19211B725	List: ML19211B728
References
REF-PT21-79-151-000 747, NUDOCS 8001030430
Download: ML19211B728 (1)

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. (W~ q, VIRGINI A ELECTRIC AND POWER COMP ANY, RICHMONO, VIRGINl A 232C1

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September 14, 1979 Mr. James P. O'Reilly, Director Serial No. 747 Office of Inspection & Enforcement PSE&C/SCJ:mac: wang U. S. Nuclear Regulatory Commission Region II Docket No. 50-339 101 Marietta Street, Suite 3100 Atienta, Georgia 30303

Dear Mr. O'Reilly:

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On September 10, 1979, a report was made under the provisions of 100FR50.55(e) concerning the Emergency Diesel Generator Fan Cooling System.

In accordance with the reporting requirements of 10CFR21, the following informatica is submitted:

A. Name and address of reporting individual:

Mr. E. A. Brum, Executive Manager Licensing and Quality Assurance Virginia Electric and Power Company P. O. Box 26666 Richmond, Virginia 23261 S. Facility, activity and/or component affected:

North Anna Power Station, Unit 2 Emergency Diesel Generator C. Name of firm constructing the facility or supplying the component, ,

activity or service:

Fairbanks Morse, Inc.

Power System Division - Colt Industries 701 Lawton Avenue -

Beloit, Wisconsin 53r11 ]g D. Description of def" t, deficiency, or failure to coaply:

The Emergency Diesel Generator Fan Cooling System for North Anna Unit 2 appears tc be inadequately designed. For any given fan blade pitch setting there is an associated ambient temperature range through which the Fan Cooling Sy:: tem can satisf actorily operate. Analysis of local meteorological data indicates that ambient temperature ranges exist which exceed the capability of the current Fan Cooling System.

For instance, if the fan blade is pitched for adequate cooling at high ambient temoeratures and low ambient temperatures occur, the fan drive system could be overloaded. Similarily, if the system is pitched for low ambient temperatures and iiigh ambient temperatures occur, the Diesel Engine will be inadequately cooled.

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8001030 Nd

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E. Date of determination of reportability:

Septsebe:- 10, 1979 F. Similar components, activities, or services: ,

florth Anna Unit 1 .

G. Corrective action which has been, is being or will 'be taken,- the individual responsible and the length of time to gomplete the action:

A meeting held September 11 & 12 between Colt Industries, Stone &

Webster, and Vepco representatives determined that various technical alternatives are available to solve the problem identified in Sectidn D. These alternatives are currently being evaluated to determine the

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most feasible solution.

H. Other information: ,

None Any informatica not available at this time will be submitted in a follow-up letter as a 30-day report.

Should you recuire further ir. formation, please contact this office.

Very truly yours, hrhll. %dhd6 A' j

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Sam C. Brown, Jr.

Senior Vice President - Power Station Engineering and Construction

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c: Director, Office of Inspection

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and Er.fcrcement (3) 2181 020