PY-CEI-NRR-0737, Special Rept:On 870923,failure of Div 3 Diesel Generator Occurred While Performing Start & Load Surveillance Test. Caused by Incomplete Investigation Into Maint Run Anomoly Which Failed to Identify Blown Fuse.Fuse Replaced

Special Rept:On 870923,failure of Div 3 Diesel Generator Occurred While Performing Start & Load Surveillance Test. Caused by Incomplete Investigation Into Maint Run Anomoly Which Failed to Identify Blown Fuse.Fuse Replaced

ML20236C454
Person / Time
Site:	Perry
Issue date:	10/23/1987
From:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
PY-CEI-NRR-0737, PY-CEI-NRR-737, NUDOCS 8710270198
Download: ML20236C454 (2)

Text

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1. 5 ,

f THE CLEVELAND ELECTR P.O.

Murray.R. Edelman DOX 97 e PERRY, OHIO 44o81 e TELEPHONE (216) 259 3737 e ADDRESS-to CENTER ROAD Serving The Best Location in the Nation PERRY NUCLEAR POWER PLANT 3R VICE i AESIDENT NWLEAR October 23, 1987 PY-CEI/NRR-0737 L g a

g 8W C Z-i 1

Document Control Desk J y U.S. Nuclear Regulatory Commission 1 Washington, D.C. 20555 k @s.

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a Perry Nuclear Power Plant N Docke t No. 50-440 Special Report -

Valid Test Failure Division 3 Diesel Generator f

Dear Sir:

Attached is a Special Report concerning a valid test f ailure of the Unit 1 Division 3 diesel generator. This report satisfies the conditions of Technical Specifications 4.8.1.1.2 and 6.9.2. j i

Please feel free to contact me should you have any further q ue s ti on s.

Very truly yours, Murray R. Edelma l Senior Vice President Nuclear Group MRE: cab Attachment cc: Paul Leech  !

K. Connaughton  !

L. Hiller (Of fice of Resource Management)

USNRC Region 171, Regional Administrator I

B710270198 871023 .

DR ADOCK0500g0

/// ,

i l

'* - Attachment -l PY-CEI/NRR-0737 L-Page 1 of 1 l SPECIAL REPORT Division 3 Diesel Generator Valid Failure i 1

On September 23, 1987, a valid failure of the Division 3 Diesel Generator l occurred while performing the Division 3 Diesel Generator Start and Load Surveillance Test. This is the third valid failure to occur on the Unit 1 l Division-3 Diesel Generator. As of September 23, 1987, the Division 3 Diesel Generator had undergone 38 valid tests, including this valid failure.

On September.22, a troubleshooting maintenance run was performed on the Division 3 Diesel Generator in order to determine proper voltage regulator operation. The test equipment was installed in accordance with Surveillance i Instruction (SVI)-E22-T1319, " Diesel Generator Start And Load Division 3". H j

During the run a discrepancy was noted between the local and control room vatt meters. Troubleshooting identified that an error in the test equipment s.

I installation had been made. The error was corrected and the SVI was run for credit on September 23. When operators attempted to parallel the Division 3 l Diesel Generator, the output breaker would not clora. Troubleshooting of the l failure to parallel identified a blown fuse in the Diesel Generator up-to-voltage permissive circuitry. With the circuit interrupted by the blown  !

fuse, an undervoltage condition is sensed preventing closure of the output I breaker. l The valid failure was due to the incomplete investigation into the maintenance run anomoly, which failed to identify the blown fuse prior to the test for credit on September 23. Investigation determined that the cause of the fuse operation vas_the test equipment installation error performed during the maintenance activity. It was identified that the error had also caused two phases of the up-to-voltage permissive circuit to be shorted, thus resulting in a blown fuse. The fuse was intact for the Start and Load portion of the maintenance run since the output breaker was able to be closed. However, since the permissive circuit is only energized during Diesel Generator operation, the most probable time of fuse operation was during'the maintenance run, after the closure of the output breaker. Since the output breaker was able to be closed while the equipment installation error existed, it was therefore erroneously determined that the permissive circuitry had not been adversely affected. Consequently, the blovn fuse was not discovered until the ,

output breaker failed to close during the subsequent attempted run for credit. l l

Following replacement of the blown fuse, the Division 3 Diesel Generator was restarted and verified operable on September 24. The Division 3 Diesel l Generator had been previously removed from service and declared inoperable on September 21, 1987 at 0525 for preplanned maintenance and was subsequently declared operable on September 24, 1987 at 1820. The total out-of-service time for the Division 3 Diesel Generator was 3 days, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and 55 minutes.

Since the Diesel Generator was not in service at the time of failure, the total out-of-service time attributed to the blown fuse was 2 days, 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, and 43 minutes. Personnel involved have been made aware of the errors and sequence of these events.

The Division 3 Diesel Generator Surveillance Test interval vill remain at once every 31 days in accordance with Technical Specification Table 4.8.1.1.2-1.