ML20134L880

Informs NRC That Commitment to Maintain & Periodically Observe/Test Dow Corning Silicone Foam Samples Is Hereby Discontinued

ML20134L880
Person / Time
Site:	North Anna
Issue date:	02/10/1997
From:	Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
97-015, 97-15, NUDOCS 9702190329
Download: ML20134L880 (2)

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. VIHOINIA ELECTRIC AND POWEH COMPANY RICIIM ON D, VIRGINI A 20261 February 10, 1997 Document Control Desk Serial No.97-015 U. S. Nuclear Regulatory Commission NLOS/ETS: R0 Washington, D. C. 20005 Docket Nos. 50-338 50-339 License Nos. NPF-4 NPF-7

Dear Sir:

VIRGINlA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 PERIODIC TESTING OF DOW CORNING SILICONE FOAM During construction of North Anna Power Station, Dow Coming Silicone Foam was used as fire barrier penetration sealant. At that time, data was not available on the long term aging characteristics of this material and what effect it might have on fire protection properties. Therefore, as part of the Operating License process, we committed to maintain foam samples at the plant and observe these samples periodically over the life of the plant for signs of deterioration. Since 1976, sample material has been maintained and periodically evaluated (approximately every 5 years) for density changes as weil as comparatively tested in flammability tests. Additionally, installed penetration seals using this foam have been subject to inspection for cracking and foam depth as part of a general plant periodic test of penetration seals.

Based on the sample evaluation results, we have determined that the material's fire protection properties are not adversely affected by aging and that the continued maintenance and periodic observation and testing of the Dow Corning Silicone Foam samples is no longer warranted. This letter is to inform the Staff that our commitment to maintain and periodically observe / test the Dow Corning Silicone Foam samples is hereby discontinued.

Existing plant inspections performed on fire barriers and the penetrations within the barriers will not be affected by this action. The station fire barriers will continue to be inspected periodically to ensure their fire protection function is maintained.

9702190329 970210 PDR p

ADOCK 05000338 PDR [hh'/ O 190001

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b' This letter does not establish any new commitments. Should you have any questions i or require additionalinformation, please contact us.

l Very truly yours, 972A-p Jamea P. O'Hanlon Senior Vice President - Nuclear cc: United States Nuclear Regulatory Commission Regional Administrator Region ll 101 Marietta Street, N. W Suite 2900 Atlanta, Georgia 30323 Mr. R. D. McWhorter NRC Senior Resident inspector North Anna Power Station I

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