PNO-III-85-099, on 851125,primary Coolant Sys Leaks Noted After Reactor Trip.Most Repairs Completed in Hot Standby. Remaining Leaks,In Two Safety Injection Check Valves & Gasket Flange for Coolant Pump,Scheduled for Cold Repair

PNO-III-85-099:on 851125,primary Coolant Sys Leaks Noted After Reactor Trip.Most Repairs Completed in Hot Standby. Remaining Leaks,In Two Safety Injection Check Valves & Gasket Flange for Coolant Pump,Scheduled for Cold Repair

ML20137Q158
Person / Time
Site:	Cook
Issue date:	11/27/1985
From:	Chrisotimos N, Hehl C, Suermann J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-85-099, PNO-III-85-99, NUDOCS 8512050179
Download: ML20137Q158 (1)

y

-PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-85-99 Data 11/27/85 g '

This preliminary notification constitutes EARLY notice of events of POSSIBLE safety Y

cr public interest significance. The information is as initially received without ,

v:rification or evaluation, and is basically all that is known by the Region III '

staff on this date.

Facility: D. C. Cook Unit 1 Licensee Emergency Classification:

Notification of an Unusual Event Dockrt No. 50-315 Alert Site Area Emergency General Emergency XX Not Applicable

Subject:

OUTAGE TO REPAIR MISCELLANE0US PRIMARY SYSTEM LEAKAGE The licensee has elected to keep Unit 1 shut down following a reactor trip on l November 25, 1985, for the purpose of repairing several valve and component I

leaks in the primary cocling system. The reactor tripped on November 25, 1985,  !

when instrument technicians inadvertently generated high negative flux rate signals during testing on the plant's nuclear instrumentation.

A subsequent examination of the reactor containment identified a number of leaking valves and components, most of which were repaired with plant in Hot Standby status. For the remaining leaks-two leaking safety injection check valves and a gasket flange leak for a reactor coolant pump-the licensee is placing the plant in C31d Shutdown. The outage is expected to last about 10 days. (The licensee did not exceed any Technical Specification leakage limits).

Tha Resident Inspectors will monitor the licensee's activities.

~

Th2 State of Michigan will be informed.

Region III (Chicago) was notified of the outage plans by the Resident Inspector at 10:00 a.m., November 27, 1985. This informtion is current as of that time.

CONTACT: f. Suermann e := w S 388-5585 C.x L

W. Hehl FTS 388-5552 N. }l.Chr/.C#

isfotimos k FTS 388-5716 '

DISTRIBUTION:

H. St. EDO NRR E/W Willste Mail: ADM:DMB Chairman Palladino PA IE NMSS 00T:Trans on.y Comm. Zech ELD OIA RES Comm. Bernthal AE0D Comm. Roberts Comm. Asselt:ine SP /,9 Regiont.1 Offices INP0).N NSAC h _f CA- RIII Resid6nt Off c PDR Licensee: M. (Corp. Office - Reactor Lic. Only)

I Region III Rev. November 1985 .

I B512050179 851127 h 3 Lf' PDR 18cE 1 PNO-III-85-099 PDR

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