ML20084J675

Ao:On 730424,during Surveillance Test of B Isolation Condensor Motor Operated Condensate Return Valve V-14-35, Breakaway from Closed Motor Current of 75 Amps Observed. Cause Undetermined.Torque Applied to Handwheel Freed Disc

ML20084J675
Person / Time
Site:	Oyster Creek
Issue date:	04/24/1973
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8305180649
Download: ML20084J675 (5)

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Subject:

Oyster Creek Station

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Docket No. 50-219 :s ,J _

Isolation Condenser Valve Failurc This event is considered to be an abnormal occurrence as defined in k h/0) the Technical Specification, Paragraph 1.15.F.

g- During the weekly surveillance test of the "B" isolation condenser motor operated condensate return valvo V-14-35, a " breakaway from closed" motor current of 75 amps was observed. The high current continued for about O 5 seconds whereupon the breaker was manually tripped. The reactor was in the cold shutdown cendition at the time of this test.

t, k Investigation is still in progress in an effort to determine the cause of this fcilure. Ikwever, as was the case upon the previous failure on

. -7 December 29, 1972, the valvo disc was finally freed from its seat only upon

,d s applying considerabic torque to the operater handuhccl. Once frec, the valvo' 4(Jk, was stroked with the motor operator to the fully opened, and then fully closed

-position several times without any difficulty. This valve had previously been b# stroked successfully on sixtcon separato occasions' during the weekly survoillance

'T tests. In all but one case, the reactor was operating at pressure and temper-U atures associated with full power operation. In addition, during this period, the "B" isolation. condensor was actuated on one occasion to assist in maintain-ing plant pressure during a shutdown. The valve and operator data are as follows:

Valve Manufacturer: Anchor Size: 10" h' edge Gate i Rating: 600 pounds .

Operator Manufacturer: Philadelphia Gear Company / Peerless lilectric-Operator Type: SNV Sizo 2 Motor Rating: 4.3 h.p. G 1900 rpm,125 fvolts DC, 35 amps

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COPY SENT REGION o . , ___ .._ -_. . - ._ ,w , . . _ . . , . _ ,.

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Mr. Giambusso April 24,1973 The requirements for at least one of the isolation condensers to act as a means of heat removal it detailed in Amendment 67 to the Oyster Creek FDSAR. Since the "II" isolation condenser would not have been able to fulfill this requirc:.:ent , the significance of this event is that the isolation condenser systen would not have had its desi ;ned redundancy.

Both the va]ve nanufacturer and the associated operator nanufacturer have been contacted to aid in our investi;ation t of this failure during our present outage.

Additional informatien will be forwarded to your office as soon as it becomes available.

Enclosed are forty (40) copies of this report.

Very truly yours ,

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7 OG .+ L (It~f u l j'i~ &Li_

e 1 Donald A. 11oss -

Manager, Nuclear Generating Stations DAR:cs linclosures (40) cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, llegion I I