PNO-III-88-088, on 881025,unit Manually Tripped from 28% Power to Avoid Challenging Reactor Protection Sys.Caused by Low Steam Generator Water Levels.Unit Expected to Be Down from Five to Seven Days While Strainers Cleaned

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PNO-III-88-088:on 881025,unit Manually Tripped from 28% Power to Avoid Challenging Reactor Protection Sys.Caused by Low Steam Generator Water Levels.Unit Expected to Be Down from Five to Seven Days While Strainers Cleaned
ML20205T070
Person / Time
Site: Braidwood Constellation icon.png
Issue date: 10/26/1988
From: Forney W, Hinds J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-88-088, PNO-III-88-88, NUDOCS 8811140098
Download: ML20205T070 (1)
v • d • e


_ _ _ _ _

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-88-88 Date October 26, 1988 1

This preliminary notification conntitutes EARLY notice of events of POSSIBLE safety QL

, or public interest significance. The information is as initially received without verification or evaluation, and is usically all that is known by the Region III staff on this date.

i Facility: Cocmonwealth Edison Company 1icensee Emergency Classification:

l Braidwood Unit 2 -

Notification of an Unusual Event i Braceyille, IL 60407 Alert 1

Site Area Emergency Docket No. 50-457 General Emergency X Not Applicabic

Subject:

SHUTDOWN TO CLEAN CONDENSATE PUMP SUCTION STRAINERS At 4:02 p.m. (CDT), October 25, 1988, the unit was manually tripped from 28 percent power to avoid challenging the reactor protecticn system. Cause of the shutdown was low steam gen;rator water levels. The water levels were decreasing rapidly due to clogged condensate pump suction strainers with a resultant reduction in flow to main feedwater pumps.

In the hour preceding the trip, operators shut down condensate pumps several times to h backflush the strainers, but conditions did not improve. In an attempt to maintain steam generator levels, power was reduced from 89 percent to 48 percent ano then to 28 percent, but thm strainer plugging persisted.

A resident inspector was onsite and monitored the manual shutdown. All systems functioned as designed.

The unit is expected to be down from 5 to 7 days while the strainers are cleaned and the causo of the clogging is determined.

Region III (Chicago) will continue to monitor the licensee's course of action.

The State cf Illinois will be notified.

R;gion III was informed of this event at 7:16 p.ni. (CDT), October 25, 1988. This information is current as of 11 a.m. (CDT), October 26, 1988.

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PDR HQS. Operations Officer /lJI Region V Region III Rev. June 1988

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