ML20090D274
| ML20090D274 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/27/1975 |
| From: | Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Anthony Giambusso Office of Nuclear Reactor Regulation |
| References | |
| AO-50-219-75-17, NUDOCS 8302250469 | |
| Download: ML20090D274 (3) | |
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hrsey Central Power & Light. Company l
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MADISON AVENUE AT PUNCH BOWL ROAD
- MORRISTOWN, N.J. 07960
- 201-539 6111 es um ar r.a General P
Public Utihties Corporation
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Director, Division of Reactor Licensing g
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Dear Mr. Giambusso:
Subject:
Oyster Creek Station Docket No. 50-219 Abnormal Occurrence Report No. 50-219/75-17 The purpose of this letter is to forward to you the attached abnormal occurrcnce report in compliance with paragraph 6.6.2.a of the Technical Specifications.
Very truly yours, 4f W Donald A. Ross, Manager Generating Stations-Nuclear es Enclosures cc:
Mr. J. P. O'Reilly, Director Office of Inspection and Enforcement, Region 1 8302250469 y h 9 7092 PDR ADOCK PDR S
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OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731
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Report Date t
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June 27, 1975
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June 19,1975 identification of Occurrence t
Failure of Core Spray System Parallel Isolation Valve (V-20-15) to demonstrate 6perability/duringsurveillancetesting. This event is considered to be an abnormal occurrence as defined in the Technica1 ' Specifications, paragraph 1.15.D.
Conditions Prior to Occurrence The plant was at steady state power with the following major parameters:
Power:
Core,1600 BMt Electric, 530 FMc Flow:
Recirculation,13.0 x 10 gpm 6
Feedwater, 5.91 x 10 lb/hr Stack Gas:
9300 uci/sec Description of Occurrence On Thursday, June 19, 1975, at approximately 1100, during the performance of surveillance testing on the four (4) Low Reactor Pressure Core Spray Valve Permissive Pressure Switches (RE 17A, B, C, and D), Core Spray System Parallel isolation Valve (V-20-15) failed to demonstrate operability.
The testing of each low pressure switch may be summarized as follows:
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r Abnormal Occurrence Report No. 50-219/75-17 Page 2 yr (1) The sensur is isolated from the roactar, pressure is bled off, and the y
5 -I,pening of the a'ssociated, parallel isolation valves is noted.
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(2),Using a test pump, a pressure in excess of 285 psig is impressed on the
densor, and the closing, of the associated parallel isolation valves
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,g (3). ! Pressure is bled off from the sensor, and the opening of the associated
. parallel isolation valves is noted.
w Valve i V-20-15) failed to close completely when step (2) was being performed t
on pressure switch (RE 17B).
It is noted that V-20-15 had previously functioned normally during the testing of pressure switch (RE 17A).
Apparent Cause of Occurrence _
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,s Investigation revealed that the' tab on the "B" phase of the valve motor breater stab was broken resulting in intermittent contact with the associated bus bar. Consequently, the lo'ss of one phase cause,d the valve motor to trip.
Analyis ot' Occurrence s
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Each core spray system is provided with two (2) parallel isolation valves which op(n'whcp a low-low reactor water level or high drywell pressure condition exists in addition to a low reactor pressure condition (<285 psig).
'the safe'ty t ignificance of this event is considered to be the loss of parallel isohtin'n valve redundancy in one core spray system.
It is noted that V-20-15 didiop's' during the surveillance testing, as would have been required during a loss of coolant accident.
Corrective Action g,,
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p Immediate NFrective action involved replacing the V-20-15 motor. breaker stab and inspecting Ihe motor breakers for the other parallel isolation valves.
The Plant Operations Review Committee concluded that tie breaker stab replace-ment is sufficient repair action when considering this type of failure.
Failure Data
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General Electric 1C7700 Line Control Center' Size I Breaker Type - FVNR Stab Babe Assembly Part No. {.171621961 g
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