ML19208C729
| ML19208C729 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/12/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 7909270288 | |
| Download: ML19208C729 (1) | |
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SUITr 202, WALNUT CREEK PLAZA WALNUT CREE K. CALIFORNI A 94596 September 12, 1979 Docket flo. 50-312 Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention:
Mr. John J. Mattimoe Assistant General Manager Gentlemen:
Enclosed is IE Bulletin 79-23 which requires action by you with regard to your power reactor facility (ies) with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, ff$$,4GC-R. H. Engelken Director
Enclosures:
1.
IE Bulletin tio. 79-23 2.
List of IE Bulletins Issued ir, the Last Six Months cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD 1049 208 009270gsg
Accession fio. 7903220104 SSlilS Nc.:
6820 UtilTED STATES liUCLEAR P,EGULATORY C0:011SSION OFFICE OF IllSPECTION AtiD EliFORCEMEllT WASHIfiGT0il, D.C.
20555 September 12, 1979 IE Bulletin ?!o. 79-23 P07EilTIAL FAILURE OF EMERGEiiCY DIESEL GEiiERATOR FIELD EXCITER TRANSFORMER Description of Circumstances _:
Florida Power and Light Company recently reported a problem encountered during a 24-hour full load test of the emergency diesel generators (EDG) at their Turkey Point facility. Approximately 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, t%s 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 IDGs which resulted in overheating of the Exciter Power Transformers (EPTs) it sustained high load operation.
The following nameplate data applies to the equipment installed at Turkey Point:
Emergency Diesel Generator General Moto. s (Electro-Motive Division) flodel EMD-999-20 Engine-turbocharged, 2 cycle, EMD design 20-645E4 Generator-EMD-design Model A-20 Exciter Power Transformer GE-single phase Model-9T24Y1004 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 naq.ral.of the conorator and the r'anteq nf the primary windings of the excitatio to as the control power transformer (-
DUPLICATE DOCUMENT between the neutrals, or a connection are equally undesirable conditions.
Entire document previously ditions exist, high circulating curre entered into system under:
cercents may exceed transformer ratin failure.
ANo 9966226/ot/
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