PNO-IV-86-003, on 860107,fire Prevention Deluge Sys Inadvertently Actuated in Auxiliary Bldg,Wetting Nonvital 480-volt Ac Load Ctr.Unit May Remain Shut Down in Excess of 2 Days During Evaluation & Drying Out of Load Ctr

PNO-IV-86-003:on 860107,fire Prevention Deluge Sys Inadvertently Actuated in Auxiliary Bldg,Wetting Nonvital 480-volt Ac Load Ctr.Unit May Remain Shut Down in Excess of 2 Days During Evaluation & Drying Out of Load Ctr

ML20136J150
Person / Time
Site:	River Bend
Issue date:	01/08/1986
From:	Jaudon J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-86-003, PNO-IV-86-3, NUDOCS 8601130226
Download: ML20136J150 (1)

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1 January' 8,' 1986 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-86-03

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This preliminary _ notification constitutes EARLY. notice of events of POSSIBLE-

,-safety or'public interest significance. -The information is as initially ,

b received without verification or evaluation, and is basically all. that is known by the Region IV staff on this date. ' -

7 , ,

1. e , y . FACILITY: Licensee > Emergency; Classification:

Gulf States Utilities Notification of Unusual Event .

. River Bend Station- ' Alert St.'Francisville, Louisiana Site Area Emergency Docket No. 50-458 General Emergency .

X Not Applicable'

r. .

SUBJECT:

' SHUT DOWN EXPECTED TO EXCEED TWO DAYS .

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n " Atrapproximately 9:15.a.m. (CST) on January _7,1986, a workman inadvertently actuated a fire-prevention deluge system in the auxiliary building. This caused-a nonvital?480 VAC load center to be wetted. The supply breaker

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tripped, causing the loss of two additional nonvital 480 VAC load centers.

4 # ' Among the power supplies which were lost was the one for the turbine

. electrohydraulic: control.(EHC) system. The EHC system also controls the J turb_ine bypass valves. The reactor was at less than 1% power with pressure control by means ~of a turbine bypass valve. This valve shut on the loss of EHC. The operators attempted to control pressure by use of steam drains; however, this resulted in_ a cool down pressure decrease and a neutron flux

' increase. This. caused a ~ reactor trip because the intermediate range monitor

. . set point was exceeded .(i.e.,125% of scale in use).

The licensee may remain shut down 19 excess of two days while evaluating this situation, drying out the wetted Ir,ad center, and-doing other maintenance.

The state of Louisiana has been'irformed.

The NRC does not plan to issue a press release.

CONTACT: J. P. Jaudon (FTS 728-814L)

DISTRIBUTION:

MAIL:

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