ML20065D480

Special Rept 90-12:on 900730,inoperability of Fire Detection Instruments in Fire Zone 356 Reported Due to Inability to Repair Detectors within 14 Days.Hourly Monitoring of Containment Air Temp Established

ML20065D480
Person / Time
Site:	Sequoyah
Issue date:	09/12/1990
From:	Wallace E TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
90-12, NUDOCS 9009250233
Download: ML20065D480 (3)

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• ' TENNESSEE VALLEY AUTHORITY CH ATTANOOG A. TENNESSEE 374o1 ,

$N 157B Lookout Place SEP 121990 i U.S. Nuclear Regulatory Comission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority )

SEQUOYAH NUCLEAR PLANT (SQN) - TECHNICAL SPECIFICATION 3.3.3.8 - SPECIAL REPORT 90-12' The enclosed special report provides details concerning the inoperability.of the fire detection instruments in Fire Zone 356 for the Unit 1 No. 2 Reactor Coolant Pump. The two thermal ftre detectors will be_out of service until the  ;

next outage of sufficient duration. This report is being submitted in accordance with Technical Specification Action Statement (b) of LCO 3.3.3.8.

If you have any questions concerning this submittal, please telephone J. W. Proffitt at (615) 843-6651.

Very ttvly yours, i TENNESSEE VALLEY AUTHORITY W ,

E. G. Wallace, Manager Nuclear Licensing and Regulatory Affairs Enclosure cc: See page 2 l

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l 9009250233 900912 PDR ADOCK0000g7 $2 2  !

l S An Equal Opportunity Employer ///

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U.S. Nuclear Regulatory Commission $(f j j jgg()

I cc (Enclosure):

Ms. S. C. Black, Deputy Director >

Project Directorate 11-4 ,

U.S. Nuclear Regulatory Commission '

One White Flint, North l 11555 Rockville Pike '

Rockville. Maryland 20852 i

i Mr. J. W. Donohew, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 j WRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road .

Soddy Daisy Tennescoe 37'79 4

Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite .*900 t Atlanta, Georgia 30323 l

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ENCLOSURE SQN SPECIAL REPORT 90-12 l i

This special report is being made in accordance with Action Statement b of ,

Limiting Condition for Operation (LCO) 3.3.3.8 because of the inability to repale inoperable fire detectors within 14 days.

On July 30,1990, at 1030 Eastern dayllsht time, with Unit 1 in Mode 1 (100 percent power, 2.235 pounds per square inch gauge and 578 degrees Fahrenheit),

LCO 3.3.3.8 was entered when the Unit 1 No. 2 Reactor Coolant Pump fire detectors were removed from service. On July 10, 1990, during performance of Preventative Maintenance (PM) 00426, " Fire Protection SYS-PWR Failure Battery Charge," maintenance personnel observed the main trouble light on Electrical Panel 0-L-631 (Module CP-30) in the aux 111ery building was indicating that a problem existed. A work request (WR-C004525) was initiated to troublesh'.at the panel. The presence of the main trouble light without any of the associated trouble lights in the various fire zones or other modules generally indicates a grounding problem in the panel (i.e., the fire zone is not inoperable). On July 30, 1990, personnel in Electrical Maintenance who were '

troubleshooting the panel discovered the conductor wires for the two thnenal-fire detectors in Zone 356 were grounded.

An hourly monitoring of the containment air temperature was established in compliance with Action Statement 3.3.3.8.a. Fire suppression capability wPs att11 available through manual initiation by operators. The inaccessibility of the detectors, because of ALARA (as low as reasonably achievable) considerations, has prevented a repair.or replacement attempt. However,

, completion of Work Request C 004525 will restore the Fire Zone 356 fire detector system to operable status during the next Unit 1 outago of sufficient duration. A determination of the exact cause of the detectors' inoperability cannot be determin 6d untti that time.

SQN will remain in LCO 3.3.3.8, and the hourly lower containment temperature monitoring will be continued until the fire zone detectors are returned operable.

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