ML19208C575
| ML19208C575 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 09/12/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Groce R VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| NUDOCS 7909270097 | |
| Download: ML19208C575 (1) | |
Text
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'o, UNITED STATES NUCLEAR REGULATORY COMMISSION y ' ).o g
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REGION I 8
631 PARK AVENUE 0,
8
,o KING OF PRUSSIA, PENNSYLVANIA 19406
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Docket No. 50-271 SEP 121979 Vermont Yankee Nuclear Power Corporation ATTN:
Mr. Robert H. Groce Licensing Engineer 20 Turnpike Road Westborough, Massachusetts 01581 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 pe mit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely,
_a PK w
oyce H. Grier
/ Director
Enclosures:
1.
List of IE Bulletins Issued in the Last Six Months cc w/encls:
W. F. Conway, Plant Superintendent Ms. J. Abbey, Technical Secretary A. Z. Roisman, Natural Resources Defense Council 1049 344 7909270b ]
ENCLOSURE 1 Accession No. 7908220104 SSINS No.:
6820 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 (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 Exci'.er Power Transformer GE-single phase Model-9T24Y1004 Serial-MD Cycles-60 KVA 15 Insulation-4160 V The manufacturer's findings and recomm are described below:
DUPLICATE DOCUMENT Entire document previously entered into system under:
79098924/6V 'l wO 3
l 1049 345 No. a vases:
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