ML19254B325
| ML19254B325 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/12/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7909270318 | |
| Download: ML19254B325 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION PDR:HQ
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September 12,1979 Docket No. 50-298 Nebraska Public Power District ATIN:
J. M. P11 ant, Director Licensing & Quality Assurance Post Office Box 499 Columbus, Nebraska 68601 Gentlemen:
Enclosed is IE Bulletin 79-23 uhich requires action by you with regard to your power reactor facility with an operating license or a construction permit.
Should you have questions regarding this IE Bulletin or the actions required of you, please contact this office.
Sincerely,
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'Karl V. Seyfrit,4 /
Director j/
Enclosures:
1.
List of IE Bulletins Issued in the Last Six Months cc:
L. C. Lessor, Superintendent Cooper Nuclear Station Post Office Box 98 Brownville, Nebraska 68321 7900270 1046 064
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-23 Date: September 12, 1979 Page 1 of 3 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 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 (EPIs) at surtained high load operation.
The following nameplate data applies to Lhe equipment installed ht Turkey Point:
Emergency Dienel Generator General Mctors (Electro-Motive Division)
Model EMD-999-20 Engine-turbacharged, 2 cycle, EMD design 20-645E4 Generator-EMD-design Model A-20 Exciter Power Transformer GE-single phase Model-9T24Y1004 Serial-MD Cycles-60 KTA 15 Insulation-4160 V The manufacturer's findings and recommendations regarding the above problem are described below:
"A potential problem can exist if the n-
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the primary windings of the excitation,
DUPLICATE DOCUMENT to as the control power transformer (CP' Entire document previously entered into system under:
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