PNO-I-88-060, on 880607,while at 100% Power,Cedm 23 Dropped Into Core.Licensee Investigation Found CEDM 23 Breaker Had Tripped on Overcurrent & Upper Gripper Coil Had Electrical Short.Plant Shut Down for Estimated 4 Days for Repair

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PNO-I-88-060:on 880607,while at 100% Power,Cedm 23 Dropped Into Core.Licensee Investigation Found CEDM 23 Breaker Had Tripped on Overcurrent & Upper Gripper Coil Had Electrical Short.Plant Shut Down for Estimated 4 Days for Repair
ML20198M954
Person / Time
Site: Millstone Dominion icon.png
Issue date: 06/07/1988
From: Bettenhausen L, Peter Habighorst, Mccabe E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-88-060, PNO-I-88-60, NUDOCS 9710300143
Download: ML20198M954 (1)


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DCS No: 50336880607

, A)^, *, " 6Q Date: June 7, 1988 pi)If

,s .

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-88-60 N I -(J o)c its 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 basi ally all that is known by the Region I staff on this date.

Facility: Licensee Emergency Classification:

Northeast Nuclear Energy Co. Notification of Unusual Event Millstone Nuclear Sta. Unit 2 Alert Docket No. 50-336 Site Area Emergency Waterford, Ct. General Emergency R E. r, X Not Applicable '

Subject:

UNPLANNEDSHUTDOWN.gEXCESSOF48 HOURS JUN-8 y On June 7,1988, at 4:22 a.m., while at h00kypower, Control Element Drive Mechanism (CEDM) #23 dropped into the core. Licensee investigation found that the CEDM-23 breaker had tripped on overcurrent, and that the upper gripper coil had an electrical short. The plant was shut down for an estimated four days for investigation and repair i

of CEDM coils. Since February 15, 1988, Millstone 2 has had a total of five CEDM failures (PNO-I-88-40, PNO-I-88-49, and this event). The resident inspectors are following licensee actions.

The licensee notified the news media of the shutdown.. The State of Connecticut has

,Jpen informed.

/ \

hisinforntioniscurrentasof9:30a.m.(EDT), June 7,1988. ,

CONTACT: P. Habighorst E. McCabe L. Bettenhausen 203-442-5357 215-337-5231 215-337-5233 DISTRIBUTION:

OWFN MNBB H-St. NL Mail: ADM:DMB th6aTrman a Zech RDb XtB RS DOT:Trans only Comm. Roberts ARM PDR Comm. Carr OGC NRC Ops Ctr Comm. Rogers INPO----

SECY NMSS NSAC----

CA NRR OGC OTA Regional Offices GPA 01 RI Resident Office PA SLITP EDO OE Licensee:

{ReactorLicensees)

Region I Fonn 63 (R;v. April 1988) g frJV OI n l boL031 9710300143 880607 PDR I&E PNO-I-88-060 PDR

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