ML20058K776

Ro:On 750209,smoke Was Observed Coming from Motor Starter for Reactor Water Cleanup Discharge Isolation Valve Caused by Shorted Relay Coil Resulting in Overheating of Control Transformer

ML20058K776
Person / Time
Site:	Monticello
Issue date:	02/10/1975
From:	Larson C NORTHERN STATES POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20058K782	List: ML20058K776 ML20058L245
References
NUDOCS 9102140382
Download: ML20058K776 (1)

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i i STATES POWER COMPANY *~f NORTHERM s s

Hunticello, Minnesota 55362 -

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. 7 February 10, 1975 .

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Mr. J. G. Keppler, Director Regim TII -

.tOffice of Inspection and Enforceury2r United States Nuclear Regulatory C==hsion o 7 t

799 Ibosevelt Road .

• Glen Ellyn, Illinois 60137 ,

Dear Mr. - Keppler:

MONTF'PT Tn MKLEAR GD EP.ATEXi PIET ~

Docket Ib. 50-263 License Ib. LFR-22 Ort February 9,1975, s:cke was observed erm%g from the motor starter for reactor water cicam:p discharge isolatica . valve, ID 2339. Investi-gation revealed that a shorted relay coil resulted in overheating of the control tr=nsformer in the r:otor starter. Failure of the centrol Neither this  ;

transformer caused the isolatica valve to be in per:ble. i

. valve nor another valve in the discharge line was placed in the c1csed position as required by Techlical Specificatien 3.7.D.2. '3he f:liled _

relay and notor starter were repicced anti the systesa was returned to norcal cperation within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Further investigation of this mience is continuing.

Yours very :nly, .

C . .x2 1,:

Plant !hnaget l,

CEL/m en 6

cc: A Giambusso G Charnoff i Minnesota Pollutien Control Agency ,

Attn: E A Pry:ina File ,>

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7102140382 750210 t CF ADDCK 05000263 '

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