ML20072G118

Special Rept 94-09:on 940711,discovered That Fire Barrier Door A-182 Damaged & Nonfunctional as Fire Barrier.Caused by Broken Tack Welds.Cause of Broken Tack Welds Cannot Be Determined.New Door Ordered

ML20072G118
Person / Time
Site:	Sequoyah
Issue date:	08/17/1994
From:	Shell R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
94-09, 94-9, NUDOCS 9408240205
Download: ML20072G118 (4)

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krnenee va*y umy Post om Box am waaroa sy wreme vro August 17, 1994 U.S. Nuclear Regulatory Commission l ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - FACILITY OPERATING LICENSES DPR-77 AND DPR TECHNICAL SPECIFICATIONS (TSs) 3.7.12, 3.7.11.2, AND 3.3.3.8 - SPECIAL REPORT 94-09 The enclosed special report provides details concerning a fire barrier door that has been damaged and determined to be nonfunctional as a fire barrier. The fire barrier will be nonfunctional for a time period greater than the TS allowable timeframe. Also, provided in the report are details concerning a sprinkler system and the associated fire detectors in the area that were declared inoperable because of a temporary structure erected to facilitate the Unit 2 Cycle 6 refueling outage activities. The sprinkler system and detectors will be administratively inoperable for a period of time greater than the TS allowable timeframe.

This report is being submitted in accordance with TS 3.7.12 Action Statement (a), TS 3.7.11.2 Action Statement (a), and TS 3.3.3.8 Action Statement (b).

If you have any questions concerning this submittal, please telephone C. H. Whittemore at (615) 843-7210.

Sincerely, I Y.

R. H. Shell Manager SQN Site Licensing Enclosure cc: See page 2 9408240205 940817 [

PDR- ADOCK 05000327 9 _ PDR '(LI -

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• e U.S. Nuclear Regulatory Commission Page 2 August 17, 1994 cc (Enclosure):

Mr. D. E. LaBarge, Project Manager U.S. Nuclear Regulatory Commission one White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711 l

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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SPECIAL REPORT 94-09 I. FIRE DOOR A-182 Qe#Sr1P_ tion of Condition On July 11, 1994, with Unit 1 in Mode 1 at 100 percent power, it was discovered that Fire Barrier Door A-182 was damaged and was nonfunctional as a fire barrier. Fire Barrier Door A-182 is on Elevation 749.0 of the auxiliary building, serving entrance to Vital Battery Room 1. Several of the tack welds that secure the door skin to the internal structure have broken. The door cannot be repaired and will be nonfunctional as a fire barrier for a period exceeding the technical specification (TS) allowable timeframe of seven days.

This condition is being reported in accordance with TS Action Statement 3.7.12(a).

Cause of condition The cause of the broken tack welds cannot be determined; however, it is theorized that the differential pressure and air flow between the vital battery room and the reactor motor-operated valve board area cause the door to slam shut with an undue force and have contributed significantly to the failure mechanism of the tack welds.

Corrective Action In accordance with Limiting Condition for Operation (LCO) 3.7.12 Action Statement (a), a roving fire patrol was established after the fire detectors on one side of the nonfunctional fire barrier were verified operable. The roving fire patrol will be maintained until the door can be replaced and the fire barrier is reestablished.

A new door has been ordered and will be installed with a different type closing mechanism to alleviate the potential for damage because of rapid closure.

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I'I . SPRINKLER SYSTEM AND DETECTORS l

Description of Condition l

On July 6, 1994, with Unit 2 in Mode 4, entering the Unit 2 Cycle 6 (U2C6) refueling outage, a portion of the fire protection sprinkler and detection system on the Unit 2 side of the auxiliary building on Elevation 690.0 was declared inoperable. The sprinkler system and i associated fire detectors are fully capable of operation. However, the sprinklers and detectors are shielded from the area of their intended coverage and, therefore, are incapable of performing their designed function. It should be noted that there are no redundant systems or components in the area that could possibly be damaged in the event of a fire.

Cause of Condition A temporary structure was erected to serve as the Radcon control point during the U2C6 refueling outage to facilitate and control personnel traffic entering and exiting lower containment. A formal operability determination was performed. The temporary structure j was determined to render the fire protection sprinklers inoperable.

Also, the structure was determined to be shielding the fire detectors in the area, thereby preventing an early detection of fire, i.e., detectors were also inoperable.

Corrective Action In accordance with LCO 3.7.11.2 Action Statement (a), a continuous fire watch was established; however, based on the formal operability evaluation stating that there are no redundant systems or components in the area that could possibly be damaged in the event of a fire, the continuous fire watch was changed to a roving fire patrol.

LCO 3.3.3.8 also requires that a roving fire patrol be established, and in accordance with LCO 3.3.3.8 Action Statement (b), a fire patrol was established for the inoperable detectors. The fire patrol will be maintained until the access to lower containment is no longer required, the Radeon uontrol point structure can be removed, and the sprinkler system and associated detectors declared operable. This is expected near the end of the U2C6 refueling outage.

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