PNO-III-86-154, on 861222,reactor Tripped from 15% Power During Testing of Integrated Control Sys.Caused by Decrease in Steam Generator Water Level Due to Feedwater Sys Control Valve Closure.Licensee Investigating Cause of Valve Closure

PNO-III-86-154:on 861222,reactor Tripped from 15% Power During Testing of Integrated Control Sys.Caused by Decrease in Steam Generator Water Level Due to Feedwater Sys Control Valve Closure.Licensee Investigating Cause of Valve Closure

ML20212F858
Person / Time
Site:	Davis Besse
Issue date:	12/23/1986
From:	Defayette R, Guldemond W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-86-154, NUDOCS 8701120194
Download: ML20212F858 (1)

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-86-154 Date December 23, 1986 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without ~ hyh v;rification or evaluation, and is basically all that is known by the Region III staff on this date.

Facility: Toledo Edison Company Licensee Emergency Classification:

Davis-Besse Nuclear Plant Notification 'of an Unusual Event Oak Harbor, OH 43449 Alert Site Area Emergency Docket No. 50-346 X GeneralEmergencyh Not Applicable

Subject:

REACTOR TRIP At 10:15 p.m. (EST), on December 22, 1986, the reactor tripped from 15 percent power during testing of the Integrated Control System. The startup feedwater system control valve closed during a test that was intended to demonstrate that the startup feedwater system would control steam generator level. Steam generator water level decreased, causing the reactor trip.

An NRC inspector was in the control room during the incident and determined that all safety systems functioned as expected. Operator response was good.

The licensee is investigating the cause of the control valve closure. Once the cause is identified and corrected, the licensee plans to take the plant to a level not exceed 40 percent power and stabilize the plant at that point through the Christmas holiday. The augmented inspection team is on site and monitoring the licensee's evaluation of the reactor trip.

The State of Ohio will be notified.

R:gion III (Chicago) was notified of the reactor trip about 11:15 p.m. (EST), December 22, 1986, by the Headquarters Duty Officer. This information is current as of 10 a.m. (EST),

December 23, 1986.

fh y CONTACT: R.DeFayetke f&k./hwn ~

W. G. Guldemond FTS 388-576/ FTS 388-5574 1 DTSTRIBUTION:

l H. St. EDO NRR E/W Willste Mail: ADM:DMB l Chairman Zech PA IE NMSS 00T:Trans only l Com. Roberts ELD OIA RES Com. Asselstine AE00 NRC Ops Ctr / /,' k ?

Conn. Bernthal Com. Carr SP M 27 7 Regional Offices ACRS SECY CA INP0 )[,*/).

RIII Edsident OffLct NSAC //,/4 M3h PDR Licensee: ///.L3 ,(Corp. Office - Reactor Lic. Only) 3 87011ho194861223 Region III ggggbe6-154PDR Rev. November 1986