ML19282B684

LER 79-024/03L-0 on 790214:fire Alarm Panel C4706 Signaled, Indicating Laundry Room Detector DS8630 as Source.Detector Declared Inoperable as No Cause for Signal Found.Cause of Event Undetermined.Possibly Due to Gases or Dust

ML19282B684
Person / Time
Site:	Davis Besse
Issue date:	03/12/1979
From:	Fulmer S TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19282B682	List: ML19282B681 ML19282B684
References
LER-79-024-03L, LER-79-24-3L, NUDOCS 7903160120
Download: ML19282B684 (2)

Text

NRC FORM 366 U. S. NUCLEAR REGULATORY COMMISSION (7 771 LICENSEE EVENT REPORT CONTFX)L BLOCK:

i l l l l l 6

lh (PLEASE PRINT OR TYPE alt REQUIRED INFORMATION) 7 o 1 8 9 l0lH l D l B l S l 141 l@l LICENSEE CODE 15 0 l 0 l- l 0 lLICENSE 0 l NNUMBEH l P l F l- 0 l 32hl@l264 l 1LICENSE l1l1 l 1 l@!5 7 C lA T b6l@

T YPE JJ CON'T l 1 l2DATE 7l9l@

" 7 10111 3$n"c 60l L l@l61 0 l 5 -l 0 l - l 0 l 3 l 4 l 668@l630 8 2kVENT 11 DATE l 4 l 7 l 974@l 7b0 l 3 REPORT

? 8 DOCKET NUVBER 80 EVENT DESCRIPTIC,N ANC PROB ABLE CONSEQUENCES h o 2 l On 2/14/79, investigation of an alarm signal from fire alarm panel C4706 indicated thel o 3 j laundry room detector DS8630 as the source. Continued investigation revealed no obscrt

[o TTI Ivable cause for the alarm. Attempts to clear the alarm failed and at 2145 hours0.0248 days <br />0.596 hours <br />0.00355 weeks <br />8.161725e-4 months <br /> on l IbE I 2/14/79, the detector DS8630 and associated panel C4706 were declared inoperable, I o e l Placind the unit in the Action Statement of T.S. 3.3.3.8. At 2235 hours0.0259 days <br />0.621 hours <br />0.0037 weeks <br />8.504175e-4 months <br /> on 2/14/79, l o 7 l maintenance personnel successfully reset DS8630, rcsnoving the unit from the Action I o a l Statement of T.S. 3.3.3.8. There was no danger to the public or unit personnel.  !

• C$'DE '#e' C0D suaCO5E COMPONENT CODE SUBC DE S E g lAlB @ ]@ W@ l Il Nl Sl Tl Rl Ul@ W@ ]@

7 8 9 10 11 12 13 la 19 20

_ SEQUENTI AL oCCURAENCE REPORT REVISION L E R. RO EVENTYEAR REPORT NO. CODE TYPE NO.

@ REPgsT

_ 21 7l 9l 22

[__. )

2J l 0l 2l 4l 24 26 y

27 l0l3l 28 lJu Ll l .--J 0l 29 31 32 K ACT Of ON PL ANT Hb HOURS 22 5 8 IT D FOR b H. SUPPLIE MAN FACTURER lA 33 lg[34.Zl g l Zl g 35 lZ [g l 0l 0l 0l 30 3/ 40 l

C@

41 lN l g lA l@ l J l 0 l 7 l 347 l@

42 43 44 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h lilol The exact cause of this occurrence is undetermined. Investigation of the equipment and g , ,, g jdetector by maintenance personnel f ailed to find any equipment malfunction. It is I

, , j possible that gases or dust given off during normal laundre operation may have caused l g, 3 l the detector to alarm. Attempts to substantiate this have proven inconclusive. l i 4 jDetector DS8630 was replaced. l 7 8 9 80 STA S '4 POWE R oTHE R STATUS ISC V HY DISCOVERY DESCRIPTION NA lA l@l Operator observation l1151 l El@ l 0l 8 l 6l@l l l ACTIVITY CO TENT RELEASED OF RELE ASE AMOUNT OF ACTIVITY LOCATION oF l'.ELEASE '

l1 l61 8 9 b @ l Z lgl NA l lNA l 7 10 11 44 45 80 PERSONNEL EXPOSURES NUMB E R TYPE DESCRIPTION NA i 7 101010 l@l Zl@l l PE RSONNE L INJURIES N U"B E R CESCRtPTION 1 H l l l l NA l

7 8 9 11 12 80 LOSS OF OR DAVAGE TO FACILITY 43 TYPE D E SC RIP TION 9 NA Ii 7 8 9 (Z l@l10 80 PUBLICITY NRC USE ONLY

, , , , , 'ggrescgI "

7 8 9 10 790316012o ,

68 69

, ,,,, ,,,,,,jg 80 = ;

M 79-032 g,ggg,png, ggg km hh pgggg WGbM, M. M g

i

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-79-28 DATE OF EVENT: February 14, 1979 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Fire alarm panci C4706 inoperable due to erroneous detector Conditions Prior to Occurrence: The unit was in Mode 1, with Power (MWT) = 2375, and Load (Gross MUE) = 795.

Description of Occurrence: At 2141 hours0.0248 days <br />0.595 hours <br />0.00354 weeks <br />8.146505e-4 months <br /> on February 14, 1979, investigation of an alarm caused by a signal frem panci C4706 indicated detector DS8630 (laundry room detector) as the signal source. Continued investigation revealed no observa-ble cause for the alarm condition. Several n':ccmpts to clear the apparently spuri-ous alarm f ailed, and at 2145 hours0.0248 days <br />0.596 hours <br />0.00355 weeks <br />8.161725e-4 months <br /> on February 14, 1979, the detector DS8630 and associated panel C4706 were declared inoperable. Although DS8630 is not a required detector per Technical Specifications, the fact that it was continuously alarming through panel C4706 rendered the panel incapable of alarming from any of its other This associated detectors, some of which are required by Technical Specifications. At placed the unit in the Action Statement of Technical Specification 3.3.3.8.

2235 hours0.0259 days <br />0.621 hours <br />0.0037 weeks <br />8.504175e-4 months <br /> on February 14, 1979, maintenance personnel successfully reset DS8630.

This removed the unit from the Action Statement of Technical Specification 3.3.3.8.

Designation of Apparent Cause of Occurrence: The exact cause of this occurrence is undetermined. Investigation of the equipment and detector by maintenance personnel f ailed to find any equipment malfunction. It is possible that gases or dust given of f during normal laundry operation may have caused the detector to alarm. Attempts to substantiate this have proven inconclusive.

Analysis of Occurrence: There was no danger to the health and safety of the public or to unit personnel. No fires occurred during this time.

Corrective Action: Upon declaring panel C4706 inoperable, an immediate search of all area monitored by the panel.was performed. Maintenance personnel were advised of the probica, and the equipment was checked for possible malfunction. ADetector fire ,

watch was instituted 'n accordance with Technical Specification 3.3.3.8.

DS8630 was replaced on February 22, 1979 under Maintenance Work Request URO 13-8-79.

Failure Data: There has been one previous reported occurrence of erroneous detector operation, see Licensee Event Report NP-33-79-22.

LER #79-024