PNO-IV-89-023, on 890327,loss of Shutdown Cooling Occurred for 12 Minutes While Tagging Out 120-volt Dc Breakers.On 890329,loss of Shutdown Cooling Occurred While Performing Work in Div I Transmitter Cabinet in Control Room

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PNO-IV-89-023:on 890327,loss of Shutdown Cooling Occurred for 12 Minutes While Tagging Out 120-volt Dc Breakers.On 890329,loss of Shutdown Cooling Occurred While Performing Work in Div I Transmitter Cabinet in Control Room
ML20247E584
Person / Time
Site: River Bend Entergy icon.png
Issue date: 03/30/1989
From: Constable G
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-89-023, NUDOCS 8904030168
Download: ML20247E584 (1)


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[ ,,_,,; 1 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- FNu-IV-89-23 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 IV staff on this.date.m FACILITY: Gulf States Utilities' Licensee Emergency Classification:

-River Bend Station Notification of Unusual Event i Docket No.'50-458 Alert -i Site Area Emergency l

LGeneral Emergency l X Not Applicable

SUBJECT:

-LOSS OF SHUTDOWN COOLING During the current River Bend Station refuelin

,resulted in the loss-of shutdown cooling (SDC)g outage, have two conditions which been encountered.

-As reported in the March 27, 1989,l daily report, loss of SDC was encountered for.

12 minutes. The condition was associated with tagging out of a 120V AC breaker in~the control room which affected the control: logic for the'"B" RHR SDC,_

reactor water cleanup, and steam line drain systems. The cause was determined to be an inadequate load list used to determine' loads on the 120V AC breaker prior to approving the clearance.

On March 29, 1989, at 11:10 p.m., the second loss of SDC occurred. The licensee

'was performing work in the Division I transmitter cabinet in the control room when an electrical technician bumped a temporary jumper _ causing-a ground on the 125V DC system. This resulted in a trip of the Division I reactor protection

. system (RPS) and the' expected Division I isolations. This resulted in the isolation of the common RHR shutdown cooling line for both RHR divisions and trip of the RHR "B" pump. Shutdown cooling was restored in 54 minutes. A

' temperature increase at the recirculation loops from 89'F to 95 F was noted.

In both cases, SDC was restored within the 1-hour Technical Specification limit.

Neither the licensee nor the NRC plans to issue a press release.

The state of Louisiana will be informed.

Region IV received notification of this occurrence by telephone from the SRI at 8 a.m., March 30, 1989. Region IV has informed EDO, NRR, and PA.

This information has been confirmed with a licensee representative.

E CONTACT: G. L. Constable FTS 728-8151 4

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