PNO-I-85-073, on 851001,unit Placed in Cold Shutdown After Ground Fault Found in Reactor Coolant Pump Motor.Pump Motor Will Be Removed to Allow Util & GE to Determine Whether Fault Accessible

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PNO-I-85-073:on 851001,unit Placed in Cold Shutdown After Ground Fault Found in Reactor Coolant Pump Motor.Pump Motor Will Be Removed to Allow Util & GE to Determine Whether Fault Accessible
ML20133D091
Person / Time
Site: Millstone Dominion icon.png
Issue date: 10/02/1985
From: Mccabe E, Shedlosky J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-85-073, PNO-I-85-73, NUDOCS 8510080042
Download: ML20133D091 (1)


DCS No: S0336851001 Date: October 2, 1985 PRELIMINARY NOTIFICATXON OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-85-73 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region I staff on this date.

Facility: Licensee Emergency Classification:

Northeast Utilities Notification of Unusual Event Millstone Unit 2 Alert Waterford, CT Site Area Emergency (DN 50-336) General Emergency X Not Applicable

Subject:

UNPLANNED PLANT SHUTDOWN IN EXCESS OF 48 HOURS Millstone Unit 2 was placed in cold shutdown at 0145, October 1, after a ground fault was found in a reactor coolant pump motor. The pump was secured as part of a plant shutdown made on September 27 as part of the preparations made for Hurricane Gloria.

When pump restart was attempted on September 28, a protective relay tripped (indicating fault current to ground in excess of 5 AMP).

Plant operation is not permitted with an inoperable reactor coolant pump. The pump motor will be removed to allow the utility and the vendor, General Electric, to investigate whether the fault is accessible. If it is, repair is possible in fourteen days. Otherwise, the utility expects delivery of a replacement 5,700 HP, 6.9 KV motor by November 1. (That replacement had been ordered as a spare in 1984.)

The fault condition apparently occurred as the motor stator windings cooled while the 1

pump and its heater were deenergized during natural circulation conditions with the plant disconnected from offsite power (the heater circuits are not on emergency power).

Media interest is expected. The state of Connecticut has been informed.

CONTACT:

J. T. Shedlosky E. C. McCabe 203-447-3179 215-337-5231 DISTRIBUTION:

H. St. MNBB Phillips E/W Willste Mail: ADM:DMB

, Chairman Palladino EDO NRR IE NMSS 00T:Trans only 4

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(Reactor Licensees)

Region I Form 83 (Rev. July,1984) 8510080042 851002 PDR I&E PNO-I-85-073 PDR

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