ML19208C719
| ML19208C719 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 09/12/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7909270275 | |
| Download: ML19208C719 (1) | |
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WALNUT CTIEE K. CALIFORNIA 94596 September 12, 1979 Docket No. 50-133 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel 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 haJe questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely,
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P/. 41 Engelken_ ;. /
Sirector
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Enclosures:
1.
List of IE Bulletins Issued in the Last Six Months cc w/ enclosures:
W. Barr, PG&E W. Raymond, PG&E E. Weeks, PGLE, Humboldt Bay 1049 183 1 tCRY) o gccames2L O
Accession tio. 7908220104 SSINS No.:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF IllSPECTION AND ENF0,.,EMENT 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 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 tt Ipped 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-9T24Y1004 Serial-MD Cycles-60 KVA 15 Insulation-4160 V The manuf acturer's findings and recommer.dations regarding the above problem are described below:
"A potential problem can exist if the j
the primary windings of the excitatio DUPLICATE DOCUMENT to as the control power transformer (
between the neutrals, or a connection Entire document previously are equally undesirable conditions.
entered into system under:
ditions exist, high circulating curre currents may exceed transformer ratin ANo WOS220/Of failure.
No. of pages:
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' 84
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