ML20045C985
| ML20045C985 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 06/17/1993 |
| From: | Stetz J CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9306250202 | |
| Download: ML20045C985 (2) | |
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e CONNECTICUT YA N K EE ATOMIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD e EAST HAMFrON. CT 06424-3099 June 17,1993 l
l U.S. Nuclear Regulatory Commission j
Document Control Desk Washington, D.C. 20555
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Reference:
Docket No. 50-213 1
Haddam Neck Plant Electrical Power System j
Inoocrable Emergency Diesel Generator
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i Gentlemen:
In accordance with the Special Reporting requirements of Technical Specification 4.8.1.1.3, Reports; Connecticut Yankee Atomic Power Company (CYAPCO) is providing the NRC staff -
with the following information.
On May 25,1993, at 13:30 hours, with the plant in Mode 6 (Refueling) the "A" Emergency Diesel Generator (D/G) failed after 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of a planned 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> full rated load endurance run in parallel with the grid. Operators had heard a sudden change in the D/G and noted local meter indications at l
approximately 1000 kw (down from a previous 2850 kw); mactive power greater than 200() Kvar IN (vs. a previous 1750 Kvar OUT) and amperage greater than 800 amps (vs. a previous 440).
Operators msponded quickly tripping the generator output breaker and shutting down the engine.
The abnormal condition existed for less than 30 seconds.
Subsequent inspections revealed that two voltage suppression devices (selenium rectiGers) had I
i shorted which caused a loss of generator Held. Corrective action included replacing all 6 voltage j
suppression devices in the 'A' & 'B' Diesel. The retest proved satisfactory. Voltage suppression device root cause investigation is ongoing and focusing on the lack of forced ventilation, dust accumulation on the devices and degradation due to age.
The total hours from the time of the diesel being declared inoperable is not applicable since the engine was taken out-of-service for scheduled routine maintenance following the failure. This is the first failum in the last 20 valid tests; therefore, the diesel test frequency remains at least once per 31 days per Technical Specincation table 4.8-1 " Diesel Generator Test Schedule". This is the j
second (2) failure in the last 100 valid tests.
The licensee contact for this Special Report is John Calderone, who may be contacted at (203) 267-3645.
Very truly yours, J. P. Stetz
%20013 Vice President, Haddam Neck Plant U
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,., m.,
9306250202 930617 a
PDf; ADDCK 05000213 4 S
PDR a
U.S. NRC Page 2 of 2 JPS:JWC/jal ec:
T. T. Martin, Regional Administration, Region I A. Wang, NRC Project Manager, Haddam Neck W. Raymond, Senior Resident Inspector, Haddam Neck J. F. Opeka, Senior Vice Pmsident of Nuclear Engineering and Operations
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R. M. Kacich, Manager of Generation Facilities Licensing 1
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