ML20096F302
| ML20096F302 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/21/1992 |
| From: | Diederich G COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9205210013 | |
| Download: ML20096F302 (1) | |
Text
Commonwealth Edison LaSane County Nuclest Statbn 2601 N. 21st. Rd.
Marsemes,IEnois 61341 Telephone 819357 6761 May 21, 1992 Mr. A. B. Davis Region III Administrator U.S. Nuclear Regulatory Comrnission 799 Roosevelt Road Glen Ellyn, 1111ools 60137 Dear Sir This Special Report is submitted in accordance with LaSalle Unit 1 Operating License NPF-11, Technical Specification 3.8.1.1, and 6.6.C regarding the Unit 1 Engineered Safety Feature (ESP) Division II (I A) Diesel Generator 1DG01KA (DG), (EK).
On April 21, 1992, with LaSalle Unit 1 in Run at 93% power, at 0516 a lockout occurred on the Unit 1 Diesel Generator 1 A.
As a conservative measure the 1A DG was declared inoperable at 0516 April 21, 1992 and the appropriate Technical Specification timeclocks were entered.
The cause of the lockout is presumed that the 1A DG Emergency Stop was inadvertently pushed instead of the Acknowledts/ Reset buttons. This occurred during the troubleshooting of the low oil pre' ure alarm circuit per work request L14553. Work request L15286 was pre}ered to investigate and attempt to duplicate the work actions that were in progress under work request L14553 when the lockout occurred.
The 1 A Diesel Generator local alarm module work was determined to have not caused the lockout through troubleshooting under work request L15286 and that the Emergency Stop pushbutton was the most probable cause.
All trips and alarms were reset and the 1A DG was successfully tested and declared operable on April 21, 1992 at 1925 in accordance with LaSalle Operating Surveillance LOS-DG-M2 " Diesel Generator-Monthly Two".
At the time of the event, the 1A DG was declared incpeaable for Unit I as a conservative measure until investigation and restoration of the 1A DG were j
complete. The corresponding Unit 1 Diesel Generator's 0, IB, and the Unit 2 l
Diesel Generator 2A were run in accordan e with Technical Specification i
3.8.1.1 Action b.
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G. J. Diederich Station Manager LaSalle County Station GJD/JR/mk1 Nuclear. Licensly Administrator cc
,j NRC Resident Inspector
/y-NRC Document Control Desk
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J h INPO - Records Center IDNS Resident Inspector 9205210013 920521 PDR ADOCK 05000373 S
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