ML19242D149

Submits Deficiency on 790802:when Process Cards,Types Nmd, Nll,Nvp & Ncb Are Inserted Into Card Slots,Heat Sinks on Transistors Could Become Grounded.Caused by Faulty Component Layout

ML19242D149
Person / Time
Site:	North Anna
Issue date:	08/03/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
G38, NUDOCS 7908140553
Download: ML19242D149 (3)

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VIRCNA ELECTA!C AP.3 PC R COMPAN cc August 3, 1979 N

c.n Mr. James P. O'Reilly, Director Serial No. 638 ,

Office of Inspection & Enforcement PSE&C/GLP:adw:me U. S. Nuclear Regulatory Commission Region II Dc'cket No. 50-339 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

On August 2,1979, a report was made under the provisions of 10CFR50.55(e) concerning the grounding of components in the Westinghouse 7300 Series Process Control System.

In accordance with the reporting requirements of 10CFR21, the following in-formation is submitted:

A. Name and address of reporting individual:

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

North Anna Power Station, Unit 2 Westinghouse 7300 Series Process Control System C. Name of firm constructing the facility or supplying the component, activity or service:

Westinghoust Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230

' sot 9 o stI 6L331 790.77f,

, 7908140 6 3, UMician copy

Mr. James P. O'Reilly 2 D. Description of defect, deficiency, or failure to comply:

When process card types NMD, NLL, NVP and NCB are inserted into their card slots, due to the component layout on the cards, the heat sinks on transistors could becone grounded by coming in contact with the card frame guide slots. When this happens operation of the card is affected. The ef t'cces of this grounding cannot always be predicted to be in the safe direction therefore errors in safety circuits could occur which are detrimental to the operation of these circuits.

E. Date of determination of reportability:

August 2, 1979 F. Similar components, activities, or services:

North Anna Unit 1 G. Corrective action which has been, is being or will be taken, the individual responsible and the length of time to ccmplete the action:

Westinghouse is reviewing the design of the aforementioned cards to eliminate the grounding problem. The site per-sonnel are working with Westinghcuse to resolve this problem, this effort is underway and will continue until all of the cards of concern have been corrected.

H. Other information:

No additional information.

Any informaticn not available at this time will be submitted in a follow-up letter as a 30-day report.

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Mr. James P. O'Reilly 3 Should you require further information, please contact this office.

.u yo ll' 'g /

C. Br wn, Jr.

Senior ice President- ove Statio Engineering an C struction cc: Director, Office of Inspection and Enforcement

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