ML20084S789

AO 50-254/75-11:on 750506,RHR Sys Svc Water Pump Declared Inoperable.Caused by Excessive Moisture within Pump Motor Around Coils.Pump Motor Sent to GE for Repairs

ML20084S789
Person / Time
Site:	Quad Cities
Issue date:	05/15/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20084S792	List: ML20084S789 ML20084S794
References
AO-50-254-75-11, NJK-75-280, NUDOCS 8306170257
Download: ML20084S789 (3)

Text

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,#N Commonwe:lth Edison

. -

• i Ouad-Cit mNuclear P0act Station -

', Post Offd ix 216 ')

/ Cordova.\.niois 61242 '

' \ ,/ Tetephone 309/654 2241 s

NJK-75-280 May 15, 1975 .

Director of Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission -

Washington, D. C'. 20555

Reference:

Quad-Ci ties Nuclear Power Station, Uni t i Docket No. 50-254, DPR-29 Appendix A, Sections 3.5.B.2, 6'.6.B.I.a Enclosed please find Abnormal Occurrence Report No. A0 50-254/75-11 for Quad-Ci ties Nuclear Power Station. This occurrence was previously reported to Region 111, Directorate of Regulatory Operations by tele-phone on May 6,1975 and to you and Region lil, Directorate of Regu-latory Operations by telecopy on May 6,1975 This repor't is submitted to you in accordance with the requirements of Technical Specification 6.6.B.1.a.

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION kr y VfbY N. J. Kalivianakis Station Superintendent NJK/BLA/lk cc: Region lil, Directorate of Regulatory Operations J. S. Abel 5523

' 8306170257 750515 PDR ADOCK 05000254 S PDR w : - ~' O

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REPORT NUMBER: A0 50-254/75-11 REPORT DATE: May 15. 1975 0CCURRENCE DATE: May 6, 1975 FACI LITY: Quad-Cities Nuclear Power Station Cordova, Illinois 61242

. IDENTIFICATION OF OCCURRENCE:

l A Residual Heat Removal system service water pump inoperable.

• CONDITIONS PRIOR TO OCCURRENCE:

Unit I was in the run mode operating at a power level of 1465 MWt and 445 Mde.

DESCRIPTION OF OCCURRENCE: -

At 8:45 am on May 6,1975, upon attempting to start 1A Resi' dual Heat Removal system service water pump to pump down the suppression pool, the pump tripped.

The contro1 switch was placed in the pull-to-lock position. The pump and motor were inspected and evidence of smoke was found in the vicinity of the motor. A work request was initiated and surveillance testing of the remaining

. components of that loop and the other containment cooling loop of the RHR system was do.ne according to Technical Specification 4.5.B.2.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

Equipment Failure The lA RHR service water pump motor was shorted out. Excessive moisture was found within the pump motor around the coils. Due to the high humidity in the RHR service water vault, the moisture allowed the coils to become grounded causing.a short which burned the motor out. -

4 ANALYSIS OF OCCURRENCE: ,

.The safety implications of this occurrence are minimal . Technical Speci-fication 4.5.B.2 allows continued plant operation providing the other three

. RHR service water. pumps are proven operable on a daily basis up to 30 days.

There are no effects on the health and safety of the public related to this occu rrence.

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.s a 9 .9 l A0 50-254/75-11 May 15. 1975 l

t CORRECTIVE ACTION:

. The l A RHR pump motor sustained damage to the stator windings. The pump motor stator has been sent to the General Electric Service Department in Bettendorf, Iowa for rewinding. The pump is expected to be returned to i service by May 27 1975 The humidity problem in the RHR service water vault has been under study

[ for some time. Proposals for resolution of the problem have been suggested by the Engineering Department and are under con' sideration .by the Station.

FAILURE DATA:

4 There has been no previous failures of this, type; therefore no safety impll- .

cations can be related to cumulative experience. a 4

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