PNO-IV-87-051, on 870927,plant Tripped from 85% Power.Caused by High Negative Flux Rate After Control Rods Fell Into Core.Cause of Dropped Rods Not Determined.Planned Shutdown for Refueling Outage Scheduled for 871001

PNO-IV-87-051:on 870927,plant Tripped from 85% Power.Caused by High Negative Flux Rate After Control Rods Fell Into Core.Cause of Dropped Rods Not Determined.Planned Shutdown for Refueling Outage Scheduled for 871001

ML20235K506
Person / Time
Site:	Wolf Creek
Issue date:	09/28/1987
From:	Hunter D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-87-051, PNO-IV-87-51, NUDOCS 8710050120
Download: ML20235K506 (1)

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September 28, 1987 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PN0-IV-87-51 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.

FACILITY: Wolf Creek Nuclear Operating Licensee Emergency Classification:

Corporation Notification of Unusual Event Wolf Creek Generating Station Alert Burlington, Kansas Site Area Emergency a DN: 50-482 General Emergency X Not Applicable ~

SUBJECT:

UNPLANNED SHUTDOWN GREATER THAN 48 HOURS On September 27, 1987, at 2:32 a.m. (CDT) Wolf Creek tripped from 85 percent ',

power. The cause of the trip was high negative flux rate after control rods fell into the core when the reactor operator moved the controlling rod group one step in the out direction. All ESF equipmerct actuated properly. The cause of the dropped rods has not yet been determined. ,

The planned shutdown for a refueling outage was scheduled for Thursday, October 1,1987; therefore, the licensee entered the refueling outage early.

The outage is scheduled to last 49 days and will include: safety and relief valve testing, NDE to look for pipe wall thinning, M0 VATS testing, and change out of 52 fuel assemblies.

Neither the licensee nor the NRC plans to issue a press release. i The state of Kansas will be informed.

Region IV received notification of this occurrence by telecon from the SRI at 7:30 a.m. Region IV has informed NRR/PA.

This information has been confirmed with a licensee representative.

CONTACT: D. R. Hunter (FTS 728-8103)

DISTRIBUTION:

MAIL: '

H. St. MNBB E/W Willste XURIDMB (Original)

Chairman Zech ED0 OIA NMSS DOT:(Trans only)

Conn. Bernthal PA AEOD RES Comm. Roberts OGC VIB FAX:

Conn. Rogers MPA OE WO Conn. Carr 01 NSAC ACRS GPA (Air SECY Rights)

CA Phillips RRI POR NRR NRC OC DCS LICENSEE.:

(Reactor Licensee)

Regional Offices goog2O870928 [

D:hRSP LJCallan:cs RAjK RD rtin

                                                                                 ~ W-87-051         PDR Transmitted 1:15p 9/28/87 - jc f

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