ML20236F019

PNO-76-222:on 761218, a DG at Millstone Threw Connecting Rod.On 761219,when Operating B DG to Demonstrate Operability Small Water Leak Was Observed Coming from Head of Heat Exchanger.Licensee Commenced Shutdown on 761219

ML20236F019
Person / Time
Site:	Millstone
Issue date:	12/20/1976
From:	Dreher F, Roy G, Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-222, NUDOCS 9807010336
Download: ML20236F019 (1)

Text

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PRELIMINARY NOTIFICATION [*

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December 20, 1976 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-76-222 I

This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance. The information I

presented is as initially received without verification or evaluation I

and is basically all that is known by IE staff on this date.

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Facility: Millstone Unit No. 2 (DN 50-336)

Subject:

UNSCHEDULED FACILITY SHUTDOWN

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The Facility has been shutdown as a result of Diesel Generator (DG) prob-lems. The length of the shutdown is not known at this time but it is expected.to last for more than seven days.

On the morning of Saturday, December 18, 1976, the "A" DG threw a connecting rod. As required by Technical Specifications the operability of the "B" DG was demonstrated at that time and subsequently on an eight hour frequency. On Sunday morning, December 19, 1976, when opera-ting the "B" DG to demonstrate operability a small water leak was ob-served coming from the head of a heat exchanger on this DG.

Subsequent l

visual examinations showed indications of cracks on heads of heat ex-l changers associated with both the "A" and "B" DGs.

I As a result of these findings the licensee commenced a shutdown at 1:25 t

p.m., December 19.

Media interest is expected because of close attention given to opera-4 tions at Millstone Point Station. The State of Connecticut has been I

informed. A press release is planned by the licensee.

NRC, Region I, (Philadelphia) received notification of this occurrence by telephone from the Operations Supervisor at 1:55 p.m., December 19, 1976.

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Contact:

FADreher, IE x27261 CWRoy, IE x27261 DThompson, IE x27541 Distribution:

Chairman Rowden Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky C. C. Kammerer, CA

0. F. Murphy, JCAE Commissioner Kennedy L. V. Gossick, EDO K. R. Chapman, NMSS R. G. Ryan, OSP S. H. Hanauer, EDO E. Volgenau, OIE J. A. Harris, PA l

B. C. Rusche, NRR H. K. Shapar, ELD T. J. McTiernan, OIA, Transmitted: PBldg

H St.

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PRELIMINARY NOTIFICATION

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9807010336 761220 PDR I&E PNO-76-222 PDR

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