ML19347C824

Ao:On 730910,isolation Condenser NE01A Condensate Return Valve V-14-34 Failed to Operate During Plant Cooldown.Cause Not Stated.Overloads Found Tripped Were Reset & New Overloads Installed.Weekly Surveillance Test Initiated

ML19347C824
Person / Time
Site:	Oyster Creek
Issue date:	09/18/1973
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8103040970
Download: ML19347C824 (2)

Text

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M ADISoN AVENUE AT PUNCH Bowl ROAD 9 M o R RISToW N, N. J. 07960 e - -611C[P 241973 c-' .L Krd. SECTION G' C3 DXY CLUtd bik'

• September 18, 1973 D

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.f[\h ss Mr. A. Giambusso Deputy Director for Reactor Projects p (I l'4 {/f s \ i b ?_p o. A Directorate of Licensing United States Atomic Energy Commission Washington, D. C. 20545 4 , N /S g *- {% -

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Dear Mr. Giambusso:

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Subject:

Oyster Creek Station l&.

O h' Docket No. S0-219 Isolation Condenser Failure The purpose of this letter is to report a failure of isolation con-denser NE01A condensate return valve V-14-34 to operate during the last stages of a plant cooldown. This event is considered to be an abnormal occurrence as defined in the Technical Specifications, Paragraph 1.15.D. Notification of this event es required by the Technical Specifications, Paragraph 6.6.2.a. ,

was made to AEC Region I, Directorate of Regulatory Operations, on September 10, 1973.

During the later stages of a plant cooldown, an attempt was made to initiate the "A" isolation condenser. The condensate return valve V-14-34, however, failed to operate. Pertinent data is as follows:

Valve Manufacturer: Crane Size: 10" Wedge Gate Operator Manufacturer: Philadelphia Gear Company / Peerless Electric Operator Type: SNV Size 2 Motor Rating: 4.3 h.p. @ 1900 rpm, 125 volts DC, 35 amps Prior to this failure, the valve had been operating successfully with no failures on previous operability surveillance tests and also had been used several times during the initial stages of the above mentioned plant cooldown.

Both overloads for the starting contactor were found tripped.

The overloads were reset and the valve was operated electrically with l no prior manual operation. It was fully stroked open and closed twice, operating satisfactorily. A trace of currents drawn by the motor was taken and compared with a trace taken the previous Thursday (September 6,1973). No differences were detected.

7/030'/6 76 .

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' Mr. Giambusso September 18, 1973 New overloads were tested and installed. Field and armature contacts were checked for corrosion and contact wipe. Shunt and series field resistance and connections were checked. All were satisfactory.

The significance of this event is the loss of redundancy of the isolation condenser system, one of which is required to act as a means for heat removal as detailed in Amendment 67 to the FDSAR.

To minimize the possibility of a reoccurrence of this event, we intend to:

1. Perform weekly surveillance tests on isolation condenser NE01A, monitoring the motor current during the test.

2. Investigate the design service of the valve motor to determine allowable number of starts per hour, ambient conditions, etc.

3. After determining the design service in "2" above, cycle V-14-34 several times to determine if the overloads trip during repeated operation. This- will be done with the original overloads and with the replacements.

We are enclosing forty copies of this report.

V ry truly yours,

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I /- / g Donald A. Ross l Manager, Nuclear Generating Stations es Enclosures cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory O} erations, Region I

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