ML20091N718
| ML20091N718 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 06/08/1984 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8406120433 | |
| Download: ML20091N718 (2) | |
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DUKE POWER GOMPANY P.O. IM)X 33 80 CHARLOTTE, N.C. 28242 HAL B. TUCKER run zenon:
n=====r (704) 373~ssa June 8, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: Catawba Nuclear Station Docket Nos. 50-413 and 50-414
Dear 5. Denton:
My letter 'of April 5,1984 provided a description of the generic and site specific problems with TDI diesel generators experienced at Catawba. Attached is a supplement to that report which describes a problem that occurred on the Catawba 1A diesel generator following the completion of the extended operation test.
Very truly yours, eA w
Hal B. Tucker
- ROS/php Attachment cc: Mr. James P. O'Reilly Palmetto Alliance Regional Administrator
_21351 Devine Street U. S. Nuclear Regulatory Commission Columbia, South Carolina 29205 Region II 101 Marietta Street, NW, Suite 2900 Mr.: Jesse L. Riley Atlanta, Georgia 30323 Carolina Environmentel Study Group 854 Henley Place
[-
.NRC' Resident Inspector Charlotte, North Carolina 28207 Catawba Nuclear Station Mr. Robert Guild, Esq.
Attorney-at-Law P. O. Box 12097 Charleston, South Carolina 29412 0
-8406120433 840608
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PDR ADOCK 05000413 L l S
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.a INTROCUCTION This supplement serves as an update to the Diesel Generator Operating Experience
~ Report forwarded to the NRC on April 5,1984. This supplement outlines the one problem that occurred on the Catawba lA diesel during maintenance runs / check-outs, following t_he completion of the extended operation test, and prior to the disassembly.of the 1A diesel for inspection purposes.
PROBLEM DESCRIPTION The problem encountered was a valid failure of the diesel to start. This failure was attributed to the Control Air System (i.e. Engine Control Panel Pneumatic Logic System) in general, but specifically a calibration drift on a component (designated Timer /NOT 9) of the Shutdown Logic Board in the Engine Control Panel.
The function of this component is to provide a time delay in the pneumatic logic to allow the pneumatic lines to precharge with air pressure and prevent pre-mature (false) signals while the engine is simultaneously reaching operating conditions.
Since the Timer /NOT 9 device had drif ted out of calibration, a premature (false) signal (i.e. lack of pneumatic air pressure) was " sensed" by the Shutdown Logic Board. The Shutdown Logic Board " sensed" the engine was in a shutdown condition, thereby not allowing the engine to start.
CORRECTIVE ACTION The corrective action taken was to recalibrate the Time /NOT 9 device by arti-fically imputting the correct pneumatic signal and adjusting the timer so the Shutdown Logic Board does not " sense" a false condition and prevent the engine from starting. In addition, procedures for periodically checking the calibration of-this timing device will be implemented following the approval of the written procedure.
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