ML19208C703
| ML19208C703 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/12/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Bryan J UNION ELECTRIC CO. |
| References | |
| NUDOCS 7909270251 | |
| Download: ML19208C703 (1) | |
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UNITEDf TATES NUCLEAR REGULATORY COMMISSION
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799 ROOSEVELT ROAD SEP 121979
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GLEN ELLYN. lLLINOIS 60137 Docket Nc. 50-4533 Docket No. 50-486 Union Electric Company ATTN:
Mr. John K. Bryan Vice President - Nuclear
'P. O. Box 149 St. Louis, MO 63166 Gentlemen:
Enclosed is IE Bulletin No. 79-23 which requires action by you with regard to your power reactor facilities with an operating license or a construction permit.
Should you have gustions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, g g.g On -
(/ James G. Keppler Director
Enclosure:
IE Bulletin No. 79-23 cc w/ enc 1:
Mr. W. H. Weber, Manager, Nuclear Construction Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Region I & IV Ms. K. Drey Hon. C. J. Frass, Chairman Missouri Public Service Commission 1049 167 Vio1196 c
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Accession No. 7908220104 SSINS No.:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 12, 1979 IE Bulletin No. 79-23 POTENTIAL FAILURE OF EMERGENCY DIESEL GENERATOR FIELD EXCITER TRANSFORMER Description of Circumstances:
Florida Power and Light Company recently reported a problem ncountered during a 24-hour full load test of the emergency diesel generators (EDG) at their Turkey Point facility.
Aoproximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> into the test, the A-EDG tripped due to a differential-relay lockout on B and C phases; the B-EDG was manually stopped, thus interrupting the test at that point in time.
Subsequent investigation and testing by the licensee revealed a design error on both the A and B EDGs which resulted in overheating of the Exciter Power Transformers (EPTs) at sustained high load operation.
The following nameplate data applies to the equipment installed at Turkey Point:
Emergency Diesel Generator General Motors (Electro-Motive Division)
Model EMD-999-20 Engine-turbocharged, 2 cycle, EMD design 20-645E4 Generator-EMD-design Model A-20 Exciter Power Transformer GE-single phase Model ?T24Y1004 Serial-MD Cycles-60 KVA 15 Insulation-4160 V The manufacturer's findings and recommendations regarding the above problem are described below:
"A potential problem can exist if the net ttfe primary windings of the excitation pc DUPLICATE DOCUMENT to as the control power transformer (CPT Entire document previously I
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