PNO-III-87-097A, on 870714,preliminary Review of Incident Determined That Startup Transformer 1-2 Faulted.Cause of Initial Fault Still Under Investigation

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PNO-III-87-097A:on 870714,preliminary Review of Incident Determined That Startup Transformer 1-2 Faulted.Cause of Initial Fault Still Under Investigation
ML20212E230
Person / Time
Site: Palisades Entergy icon.png
Issue date: 07/15/1987
From: Burgess B, Guldemond W
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-87-097A, PNO-III-87-97A, NUDOCS 9711030110
Download: ML20212E230 (1)


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PRELIMINARY NdTIFIb iIO F0F EVENf 0R URUcVAL OCCURRENCE--PN0 l ill-87-9 A Date July 15, 1987 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without v;rification

'~

or evaluation, and is basically all that is known by the Region 111 on this date, g

L /ity: Consumers Power Company Licensee Emergency Classification:

Palisades X Notification of an Unusual Event Covert, MI 49043 Alert Site Area Emergency Docket No. 50-255 General Emergency

_Not Applicable

Subject:

LOSS OF 0FF-SITE POWER----(UPDATE)

Off-site power was restored to the PaE6ades plent at 8:48 p.m. (EDT) on July 14, 1987, by backfeeding power through the main transfonner, which is the method of supplyinq power to the plant during refueling outages..

classification was terminated at thab{ollowing restoration of power, the Unusud Event '

M tinit i? A 7 :33 A preliminary review of the incident determined that the Startup Transformer 1-2 faulted at about 1:22 p.m. on July 14, 1987. The transformer fault caused the rear switchyard bus to isolate, shutting off power to some nonsafety-related systems including the cooling tower pumps and fans. Recognizing that the plant would trip shortly after losing the cooling tower systems, reactor operators manually tripped the reactor. The two emergency diesel generators started automatically to supply power to essential safety systems.

The cause of the inicial fault is still under twestigation. Technicians were working on the

.transfonner at the time of the incident, and the deluge fire-protection system was set off.

/N

( ). C. Cook resirient inspectors were promptly dispatched to the site, and they were jo..ld later in the day by the Palisades resident inspector. There was continuous inspection coverage while the plant wat powered by the diesel generators and through the night.

An Augmented Inspection Team (AIT) has been formed, headed by a Region III (Chicago) section chief and including electrical specialists from Region III and the Office of Nuclear Reactor R:gulation. The team is on site, reviewing the circumstances of the event and the licensee's response. ,

The State of Michigan will be infsrmed of this updated information.

The licensee issued a news announcement on July 14, 1987. I This infnmation is current as of 2 D.m. (EDT), July 15, 1987.

97110301.0 870715 h(!

PDR I&E PNO-ITI-87-97A PDR Lurtini: o; surgess tr o aco-noous W. Guldemond (FTS 388-5574)

DISTRIBUTION:

H. St. ED0 NRR E/W Willste Mail: ADM:0MB Chairmen Zech PA IE NMSS D0T:Trans only Comm. Roberts ELD OIA RES Conn. Asselstine AE00 NRC Ops Ctr Comm. Bernthal F~ T Carr SP Regional Offices i )

U NSAC i c o e u l INP D'

C R Distribution: Chm, Cmes (Corp. Office - Reactor Lic. Only)

, GC, CA, ApIW, Historian, SECY, Records.

Region III

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