ML20012A011

Special Rept 90-03:on 900121,trouble Alarm on Fire Protection Panel O-L-630 Observed.Caused by Malfunction of Fire Detector in Fire Zone 353 Located in Lower Compartment of Unit 2 Containment.Work Request Initiated

ML20012A011
Person / Time
Site:	Sequoyah
Issue date:	03/01/1990
From:	Wallace E TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
90-03, 90-3, NUDOCS 9003080124
Download: ML20012A011 (3)

Text

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. TENNESSEE MALLEY AUTHORITY h

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. U.S.. Ni Jar Regulatory Commission ATTN:. Document Control Desk Washington, D.C.

'20555 Gentlement In the Matter of

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Docket Nos. 50-327 Tennessee Valley Authority

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50-328

=SEQUOYAH NUCLEAR PLANT (SQN) TECHNICAL SPECIFICATION (TS) 3.3.3.8 - SPECIAL

REPORT 90-03 The enclosed special ~ report provides details concerning the fire detection-instrumentation Inside Unit 2 containment on Elevation 693 for Fire Zone 353 being~ declared inoperable. These detectors are in the area of the lower compartment coolers.

This report is being submitted in accordance with 1S Is Action Statement b of Limiting Condition for Operation 3.3.3.8.

If.you have any questions concerning this submittal, please telephone a-

'M. A. Cooper at (615) 843-6651.

Very truly yours,

. TENNESSEE VALLEY AUTHORITY i

/' g E. G. Ha lace, Manager Nuclear Licensing and Regulatory Affairs Enclosure cc: See page 2 i

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g An Equal Oppc anity Employer 5

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' U.S. Nuclear' Regulatory Commission el a cc (Enclosure):

Ms. S. C. Black, Assistant Director for Projects s

TVA Projects Division U.S. Nuclear Regulatory Commission 6:

One White Flint, North 11555 Rockville Pike i;

Rockville, Maryland 20852 i:

Mr. B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division U.S.' Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road i

Soddy Daisy, Tennessee 37379 i

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L ENCLOSURE SQN SPECIAL REPORT 90-03

-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 repatr~1noperable fire detectors within 14 days.

On January 21, 1990, at 2050 Eastern standard time, with Units 1 and 2 in Mode 1 (100 percent power, 2,235 pounds per square inch gauge and 578 degrees Fahrenheit), LC0 3.3.3.8 was entered when a trouble alarm on fire protection Panel 0-L-630 was observed. An investigation into the situation revealed that a fire detector in Fire Zone 353 had apparently malfunctioned.

Fire Zone 353 is located inside the lower compartment of Unit 2 containment and contains four detectors; a failure of any or all of these detectors results in receipt of the aforementioned alarm.

TS 3.3.3.8 requires that all four detectors must be operable.

-An hourly monitoring of the containment air temperature was established in compliance with Action Statement 3.3.3.8.a.

Fire suppression capability was still available through manual initiation by operators.

The inaccessibility of the detectors, because of ALARA (as low as reasonably achieveable) considerations, has prevented a repair or replacement attempt.

However, Work Request B-793467 has been initiated to restore the Zone 353 fire detector system to operable status during the next Unit 2 outage of sufficient duration. A determination of the exact cause of the detector (s) inoperability cannot be determined until that time.

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

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