PNO-III-88-016, on 880304,licensee Declared Alert After Both Trains of Decay Heat Removal Sys Were Declared Inoperable

PNO-III-88-016:on 880304,licensee Declared Alert After Both Trains of Decay Heat Removal Sys Were Declared Inoperable

ML20198M899
Person / Time
Site:	Davis Besse
Issue date:	03/07/1988
From:	Defayette R, Knop R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-88-016, PNO-III-88-16, NUDOCS 9710300094
Download: ML20198M899 (1)

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PRELIMINARY NOTIFICATION OF EVENT OR

} ., gg9,p UNU U L OCCU:JENCE -PNO Date March 7, p!!!-8816 1988 This preliminary notification constitutes EARLY notice of events of POS$1BLE safety or public interest significance. The information is as initially received without

, [mS. verification or evaluation, and is basically all that is known by the Region !!!

t staff on this date.

Facility: Toled< Edison Co. Licensee Emergency Classification:

5503 N. State Route 2 Notification of an Unusual Event Oak Harbor, OH 43449 C Alert Site Area Emergency Docket No: 50-346- General Emergency Not Applicable

Subject:

STATION ALERT At 6:43 p.m. (EST), March 4,1988, with the unit at 61 percent power, the licensee declared an " Alert" after both trains of the decay heat removal system were declared inoperable.

The alert, which only lasted 12 minutes, was precipitated by the failure of a service water valve to remain in the fully opened position, as required. Decay heat cooler outlet valves l in the decay heat removal system were similar in design-to the failed service water valve.

Since the valves are similar, the licensee believed the Decay Heat Removal Systems valves also could potentially fail. It took the licensee 12 minutes to assure that the valves would function as designed in an emergency and during that time they were technically inoperable and an " alert" therefore was declared. (Under the licensee's emergency classification system, an alert is declared when both trains of the Decay Heat Removal System are lost.)

[ The licensee is investigating the cause of the service water valve problem. Region !!! and

' the Resident inspectors are monit> ring the licensee's course of action. The unit will be shut down for a six-month refueling and maintenance outage beginning March 10, 1988.

The State of Ohio will be notified.

Region !!! (Chicago) first learned of this event at 7:26 p.m. (EST), March 4,1988. This infonnation is current as of 4:15 p.m. (EST), March 7,1988.

CONTACT: R. DeFayette. R. Knop-388-5767 388-5547 I O!STRIBUTION: h \

H. St. NMBB Phillips E/W WFN 1 Chainnan Zech XEUU NRR DTK K r Comm. Roberts Comm. Bernthal Conn. Carr -

ARM EDO AirRights 01 Mail To:

DC5 (Original) hh ,

PA SLITP Conn. Rogers OGC DOT (Trans. Only)

SECY l OGC-H FAX TO: Nicholson Lane Regions CA TNN~ RE5 Region I GPA NSAC Region !!

ACRS Licensee Region IV PDR Resident Inspector Region V HQS. Operations Officer

.n Region !!!

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"'s01O Rev. November 1987 C/R Distribution: Chm, Cmrs, GFA, GC, CA, PDR Historian.

SECY. Records, go 94 ago3oy PND-III-88-16 PDR .

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