ML19095A443

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

ML19095A443
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: ML19095A443 (2)

Text

f-E -p VIROINlA - ~ LECTRIC .AND OWER C

OMPANY

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RICHMOND,Vl: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 230 Peachtree Street, Northwest Atlanta, Georgia 30303

Dear Mr. O'Reilly:

This letter is in response to IE Bulletin Nos. 77~05 and 77-05A 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 with 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.

The 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,

u. 221. ~itC:/~J,:J/

C*. M. Stallings Vice President-Power Supply and Production Operations AttacJunent cc: Mr. Robert W. Reid

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DESCRIPTION OF TEST Amphenol Connectors used at Surry Units 1 and 2:

1. 280°F at 60 psia for 60 min.

2. 140-150°F 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.SMQ.

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