PNO-III-80-230, on 801014,reactor Tripped Off Line.Caused by Fire in Generator Pilot Exciter Unit Resulting in Low Voltage Signal to Reactor Protection Sys.Fire Extinguished & Generator Depressurized & Flooded W/Carbon Dioxide
| ML17319A700 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/15/1980 |
| From: | Ridgway K, Streeter J, Swanson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| References | |
| PNO-III-80-230, NUDOCS 8102180701 | |
| Download: ML17319A700 (4) | |
PRELIMINARY NOTIFICATION
. ~
pate December 15, 1980 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO III BO 80-230 This reliminar notification constitutes EARLY notice of events of POSSIBLE safet or ublic interest si nificance.
The information resented is as initiall received without'erification or evaluation and is basicall all that is known b
IE staff as of this date.
~Fecilit American Electric Power Service Corporation Indiana
& Michigan Power Company D.
C.
Cook Unit 2 (Docket No. 50-316)
Bridgman, HI
~Scb 'et:
FIRE IN HAIN GENERATOR EXCITER At 10:18 p.m.
(EST) on December 14, 1980, while operating at 100% power, the reactor was tripped off the line by a fire in the generator pilot exciter unit.
Malfunction of the exciter caused a low voltage signal to the Reactor Protection System causing the reactor trip (Reactor Coolant Pump undervoltage).
This also caused a 30 second delay trip of the main generator.
During the 30 second delay, excitation fluctua-tions caused the voltage to drop to less than 80% which resulted in a blackout sig-nal.
The emergency diesels started normally and the emergency busses were isolated normally.
The Reactor Coolant Pumps did'ot trip and the shutdown to hot standby was normal with no engineered safety facility actuations The fire in the exciter was observed when it started by an operator who reported it and then fought it with the aid of the firebrigade.
The fire was extinguished at 10:55 p.m.
The local fire department was notified and responded but they were not needed.
The generator was depressurized of hydrogen and flooded with CO as a safety precaution.
Cause of the fire was attributed to faulty wiring/insulation at the terminal junction box of the exciter.
The pilot exciter is expected to be replaced within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
The licensee notified the state and issued a press release to a local radio station.
This PN is for information only and is current as of 3:00 p.m.
on 12/15/80.
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PREL IMINARY NOT IFI CAT ION PNO-I I I 230 Page 2 of 2 Ig.LK
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s'.
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