ML20045D907

Special Rept:From 930511-0611,7 Fire Detectors in Circuit FLP3-3 Out of Svc for 32 Days.Caused by Failed Fire Detector.Detector Replaced & Containment Air Temps Monitored Hourly

ML20045D907
Person / Time
Site:	Millstone
Issue date:	06/24/1993
From:	Haynes H, Scace S NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
MP-93-506, NUDOCS 9306300199
Download: ML20045D907 (1)

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MORYHEAST tmLMES oen-a' o*a San s"* Ba conna I kesheNa$s[e$$"e'ttNe$r$c co[ pun [ P.O. BOX 270 Eo'rIn*a5NtStI*ESE o cany HARTFORD. CONNECTICUT 06141-0270 L 'T 2 Northeast Nuciear Ene gy Compani (203)665-5000 )

i June 24, 1993

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Re: Yec$icaI5pecification 3.3.3.7.b U. S. Nuclear Regulatory Commission l Document Control Desk Washington, D. C. 20555  ;

Reference:

Facility Operating License No. DPR-65 Docket No. 50-336 Gentlemen:

This letter forwards the Special Report required to be submitted pursuant to Technical Specification 3.3.3.7.b. This report identifies that the seven (7) fire detectors in circuit FLP3-3, for the East Penetration area, Zone 37, within Containment listed in Technical Specification table 3.3-10, item number 1, were out of service for 32 days (5/11/93 to 6/11/93). The seven detectors were not in service due to one detector failure.

A Containment entry was made and a failed fire detector was found and replaced. The ,

FLP3-3 detectors are wired such that a failure of one will mask all other detectors in that '

circuit from alarming on the local panel (FLP3) or the main control room, thus making the complete set of detectors inoperable. During the 32 days the detectors were inoperable the plant complied with action "a" of Technical Specification 3.3.3.7, by 1 monitoring Containment air temperatures.

The event is being reported in accordance with Specification 6.9.2 and Technical Specification 3.3.3.7.b. There were no safety consequences resulting from this event, because the plant complied with action "a" of Technical Specification 3.3.3.7. This action requires an mspection of the Containment at least once very 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or monitoring of the Containment air temperatures at least one per hour at the location listed in Specification 4.6.1.5, which provides a cood representation of the Containment air 1 temperature in the East Penetration area. These air temperatures were monitored hourly in accordance with Technical Specification 3.3.3.7.b, until the failed detector was replaced on 6/11/93.

We trust you find this information satisfactory.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY FOR: Stephen E. Scace Vice President - Millstone Station 290001 BY:

1 ctt Harr.u F F y es 2 '

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Millstone Un' 1 Directd SES:ljs ec: T. T. Martin, Recion 1 Administrator P. D. Swetland Senior Resident Inspector, Mills'one Unit Nos.1, 2 and 3 G. S. Vissing, NRC Project Manager, Millstone Unit No. 2

$// d n 7/ yW763 eaceaonie, eaosu PDR S

ADOCK 05000336 PliTD

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