ML20029A406

Provides Details Re 6.9-kV Diesel Generators Installed at Plant.Rept Submitted in Accordance W/Tech Spec 6.9.2.2

ML20029A406
Person / Time
Site:	Sequoyah
Issue date:	02/19/1991
From:	Wallace E TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9102210338
Download: ML20029A406 (3)

Text

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Gentlemen In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-320 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS I AND 2 - DIESEL GENERATOR RELIABILITY DATA REPORT The enclosed report provides details concerning the 6.9-kilovolt diesel 5:. aerators installed at SQN. This report is being submitted in accordance with Technical Specification 6.9.2.2.

Please direct questions concerning this issue to J. D. Smith at (615) 843-6672.

Very truly yours, TENNESSEE VALLEY AUTil0RITY E. G. Wallace, Manager Nuclear Licensinr,and Regulatory Affairs Enclosure ec: See page 2 0

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Ms. S. C. Black Deputy Director Project Directorate 11-4 U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockvillo Pike Rockville, Maryland 20852 Mr. J. N. Donohew, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 NRC Hosident inspector Sequoyah Nucicar Plant 2600 Igou Ferry Road Soddy Daisy, Tennesseo 37379 Mr. B. A. Wilson, Project Chief U.S. Nucicar Regulatory Commission Region II 101 Marietta Street, NW, Laite 2900 Atlanta, Georgia 30323

1/28/91 SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DIESEL GEllERATOR RELIABILITY DATA REPORT This report is abmitted pursuant to Technical Specification 6.9.2.2 to satisf y the rer.tirement for a yearly data report on diesel generator (DG) reliability. Tne 6.9-kilovolt (kV) DGs at Sequoyah Nuclear Piant serve as the onsite Class 1E power source. Surveillance requirements of technical specifications that demonstrate DG operability are accomplished by the routine performance of Surveillance Instruction (SI) 7, ' Electrical Power System:

Diesel Generators Unit 0,1, and 2," SI-7.1, " Diesel Generator AC Electrical Power Source Operability Verification (Diesel Generator /Offsite Source) -

Units 1 and 2," the SI-26 series f or loss of of f site power coincident with a safety injection, and the S1-102 series f or the inspection of DGs. Listed below is a tabulation of DG testing data recorded during the perf ormance of the aforementioned sis as well as data recorded during the performance of special test instructions and special maintenance instructions. The data was taken from testing performed during the period between January 1, 1990, and December 31, 1990. " Valid tests" and " invalid tests" are defined in accordance witu the criteria established in Regulatory Guide 1.108, Revision 1. August 1977.

Diesel Generator Valid Tests Invalid Tests failures 1A-A 18 16 0 18-B 20 17 0 2A-A 17 17 0 28-B 16 23 0 The above data of approximately 36 starts per DG with no recorded f ailures supports the conclusion that the reliable perf ormance of the 6.9-kV DGs at Sequoyah provides a high confidence level the DGs will perform if reqJired.

TVA continues to recognize the importance of reducing the number of DG starts as indicated by the below downward trend.

1988: = 170 Starts Per DG Per Year 1989: = SS Starts Per DG Per Year 1990: = 36 Starts Per DG Per Year This continued effort has greatly reduced the number of starts of each 6.9-kV DG, thereby increasing engine life without compromising reliability.

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