ML20090D855

AO-50-219/74-57:on 741108,stack Gas Sample Line Low Flow Alarm Received Due to Stack Gas Sample Pump Not Operating. Cause Under Investigation.Pump Restarted

ML20090D855
Person / Time
Site:	Oyster Creek
Issue date:	11/18/1974
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-50-219-74-57, NUDOCS 8303030285
Download: ML20090D855 (4)

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.ersey Centra Power & Lig7t Company . S'

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MADISON AVENUE AT PUNCH BOWL ROAD + MORRISTOWN. N.J. 07960

• 201-533-6111 ND nest R OF Tore Generat ,}

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November 18, 1974 / V' , , , 'A;.

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M:. A. Giambusso .' fe. Deputy Director for Reactor Projects s r.- :e /W

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Directorate of Licensing United States Atomic Energy Commission h*ashington, D. C. 20545

Subject:

Oyster Creek Station Docket No. 50-219 Abnormal Occurrence Report No. 50-219/74-57 The purpose of this letter is to forw trd to you the attached Abnormal Occurrence Report in conpliance with 1.aragraph L.6.2.a of the Technical Speci-ficat ion s . Enclosed are forty copies of this submittal. Very truly yours,

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j'Gl $ , W E N .' p V :!-f - - - . Donald A. Ross ( Manager, Generating Stations-Nuc1 car pk Enclosures cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1 esR3RB8Ef0M!s)*g 11863 S

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   .ersey Centra Power & Lig7t Company w(     f MADISON AVENUE AT PUNCH BOWL ROAD

• MORRISTOWN.N.J.07960
• 201-$39-6111 us u w rn General f> ,,.[,[* Public Utilities Corporation mn.

OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08731 Abnormal Occurrence Report No. 50-219/74-57 Report Date November 18, 1974 Occurrence Date November S,1974 Identification of Occurrence Violation of the Technical Speci fications, paragraph 3.6. A.3, failure of the stack gas sarple system to continuously monitor stack releases while the reactor was in an unisolated condition. This event is considered to be an abnormal occurrence as defined in the Technical Specifications, paragraph 1.15B. Conditions Prior to Occurrence The plant was at steady state power with major parameters as follows: Power: Core, 1912 MWt l Electric , 655 Mh'e Flow: Recirculation, 15.6 x 104 gpm i Feedwater, 7.22 x 106 lb/hr Reactor Pressure: 1020 psig Stack Gas: 20,625 pCi/sec l

O Abnormal Occurrence Report No. 50-219/74-57 o Page 2 4 Description of Occurrence ~ At approximately 1220 on November 8, 1974, a stack gas sample line low flow alarm was received in the control room. An operator was dispatched to check the stack gas sample pump. At 1222, it was reported that the stack gas sample pump was not operating. The stack gas sample pump was restarted at 1224 by placing the circuit breaker on instrument panel 4C in the 460V switchgear room in the ON position. The total time the stack gas sample pump was out of service was approximately four minutes. Apparent Cause of Occurrence 1he cause of this occurrence is still under investigation. The circuit breakers and the thermal overload breaker will be replaced, and the removed breakers will be tested. Analysis of Occurrence A review of the stack gas radiation monitor recorder traces showed the levels of both monitor channels to be relatively constant (at 650 cps) with no spiking before and after the pump trip. In a farther effort to determine if excessive stack releases might have occurred during the approximate four minute period that the stack gas sample pump was not operating, recorder traces of radiation monitoring systems associated with two gaseous streams released through the stack were reviewed. A review of the off gas radiation monitor recorder traces showed that the levels of both monitor channels were relatively constant (at approximately 1.4 x 103 mr/hr) with no spiking for a period of approximately sixty minuteu prior to this event. Sixty mir.utes is the off gas system holdup time prior to releasing to the stack. In addition, a review of the reactor building ventilation exhaust radiation monitor recorder traces showed that at the tine of this event, the levels of both monitor channels were relatively constant (at approximately 2.0 mr/hr) with no spiking. Based on these con-siderations and the very short period of time that the stack gas sampic pump was not operating, the safety significance of this event is considered to be minimal. Corrective Action The stack gas sampic pump was restarted by placing the circuit breaker in the ON position. The present circuit breaker and thermal overload breaker are being replaced with larger breakers and provisions are being made in the stack gas sampic system for a redundant sample pump.

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                                -                     ph Abnormal Occurrence Report No. 50-219/74-57

() Page 3 Failure Data 4 Previous abnormal occurrences involving the stack gas sample pump are: i

1. Abnormal Occurrence Report No. 50-219/74-53

2. Abnormal Occurrence Report No. 50-219/74-54 l .

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