ML19095A446

Response to IE Bulletin Nos. 77-05,77-05A, & NRC Letter of 11/18/1977, Enclosed Study Results Regarding Environmental Qualifications of Electrical Connectors

ML19095A446
Person / Time
Site:	Surry
Issue date:	12/07/1977
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	O'Reilly J NRC/RGN-II
References
IEB-77-005, IEB-77-005A, Serial No. 529/111877
Download: ML19095A446 (2)

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e VIRGINIA ELECTRIC AND PowER COMPANY RIOHMOND,VJ:RGINIA 23261 December 7, 1977 Mr. James_P. O'Reilly, Director Serial No. 529/111877 Office of Inspection and Enforcement LQA/JEE:jal

U.:S. Nuclear Regulatory Commission Region II Docket Nos. 50-280 230 Peachtree Street, Northwest 50-281 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

This letter is in response to IE Bulletin Nos. 77..:.05 and 77-0SA and Mr. Case's letter of November 18, 1977, concerning environmental qualifications of electrical connectors subject to an accident environ-ment and are required to be operable during an accident. A study has been conducted and.we have found that the only electrical connectors required for safety are the channels needed for reactor trip during a LOCA - low pressurizer level and low pressurizer pressure. These channels would actuate a reactor and turbine trip within the first seconds well before accident radiation levels are reached or the commencement of caustic sprays, therefore, these connectors (manufactured by Amphenol) would not be exposed to high radiation or caustic sprays before their function was completed~

On November 16, 1977, our Messrs. W~ F. Bennett and J.M. Davis met wi:th Messrs. T. A. Ippolito and M. B. Fairtile when test_ results on the Amphenol connectors for accident steam, temperature, and pressure conditions were presented. The staff found the results acceptable. A brief description of the test is attached.

It is our conclusion that no other electrical connectors inside or outside the containment would be required to function during an accident.

Tile Amphenol Connectors described above will not be required to operate beyond the first seconds into the accident before further degradation of the containment environment and would not compromise the operation of safety-related equipment.

Very truly yours,

~' }?? \.dkia~J.cY' C. M. Stallings Vice President-Power Supply and Production Operations Attachment t. 0 l'rv Mr. Robert:W. Reid cc:

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e e DESCRIPTION OF TEST

. Amphenol Connectors used at Surry Units 1 and 2:

1. 28QGF at 60 psia for 60 min.

2. 140-lSQGF at atmospheric for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

RESULTS: Insulation Resistance never fell below 34.SMn.

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