ML20137P522

Informs of Necessity to Address Changes Re Addition of Common Station Svc Transformer in Any Justification for Not Performing Verification Test.Changes Effect Processing Sys & Electrical Sys Configuration

ML20137P522
Person / Time
Site:	Sequoyah
Issue date:	01/31/1986
From:	Youngblood B Office of Nuclear Reactor Regulation
To:	White S TENNESSEE VALLEY AUTHORITY
References
NUDOCS 8602050200
Download: ML20137P522 (2)

Text

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l Docket Nos.: 50-327 and 50-328 JAN 311986 Mr. Steven A. White  !

J Manager of Nuclear Power l Tennessee Valley Authority i 6 North 38A Lookout Place Chattanooga, Tennessee 37401 I

Subject:

Sequoyah Nuclear Plant - Verification Test for the Auxiliary Power i Systems Voltage Study 1

1 i During our telecon of January 8,1986 with your staff, and our site visit on January 14-16, 1986, we discussed the question of whether the computer model used to analyze the auxiliary power system f(APS) voltage study 1 will be verified by an actual test. Your staff explained during nur January 14-16 meeting at Sequoyah that the previous voltage study used an analytical model developed for the main frame computer while the new APS voltaqe study is  ;

being performed on the IBM PC. They assured us that the governing formulas, i logics, and assumptions of the two models are compatible. Therefore, they i intend to justify not performing the verification test. We indicated that j we will review their justification when provided. Also, we learned that TVA i

has added one comon station service transformer (making a total of three t such transformers) to relieve loadinq on the transformers and to improve the distribution bus voltage profile.

In view of the fact that there have been channes in the processing system and electrical system configuration which may influence the system voltage calcula-tion results, these changes must he addressed in any justification that no verification test is nacessary, Sincerd ydth,,t, % m M 23Ob$ 0$bo$hn7 R. J. Youngblood, Director j p PDR PWR Project Directorate 84 Olvision of PWR Licensinq-A j cc: See next page t l

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JAN 31 m Mr.

Tennessee Valley Authority Sequoyah Nuclear Plant cc: ^

Herbert S. Sanger, Jr., Esq. Tennessee Department of Public General Counsel Health Tennessee Valley Authority ATTN: Director, Bureau of 400 West Sumit Hill Drive. E 11B 33 Environmental Health Services Knoxville, Tennessee 37902 Cordell Hull Building Nashville, Tennessee 37219 Mr. K. W. Whitt Mr. Michael H. Mobley, Director Tennessee Valley Authority Division of Radiological Health 400 West Sumit Hill Drive, E3A8 T.E.R.R.A. Building Knoxville, Tennessee 37902 150 9th Avenue North Nashville, Tennessee 37203 Mr. Bob Faas Westinghouse Electric Corp. County Judge P.O. Box 355 Hamilton County Courthouse Pittsburgh, Pennsylvania 15230 Chattanooga, Tennessee 37402 Mr. Jerry Wills Tennessee Valley Authority 5N 133 Lookout Place Chattanooga, Tennessee 37402-2801 Mr. Donald L. Williams, Jr.

Tennessee Valley Authority 400 West Sumit Hill Drive, W10885 Knoxville, Tennessee 37902 Resident Inspector /Sequoyah NPS c/o U.S. Nuclear Regulatory Comission 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 Regional Administrator, Region !!

U.S. Nuclear Regulatory Comission, 101 Marietta Street, N.W., Suite 2900 Atlanta, Georgia 30323 Mr. Everett Whitaker Tennessee Valley Authority SN 1288 Lookout Place Chattanooga, Tennessee 37402-2801