ML19208C675

From kanterella
Jump to navigation Jump to search
Forwards IE Bulletin 79-23, Potential Failure of Emergency Diesel Generator Field Exciter Transformer. Action Required
ML19208C675
Person / Time
Site: Zimmer
Issue date: 09/12/1979
From: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To: Borgmann E
CINCINNATI GAS & ELECTRIC CO.
References
NUDOCS 7909270216
Download: ML19208C675 (1)


Text

[b

  1. j a arouq'o, UNITED STATES

!" )A(g

,n NUCLEAR REGULATORY COMMISSION f E REGION 111 ok p'f 799 ROOSEVELT ROAD

% *.\\/

g GLEN ELLYN. ILLINotS 60137 SEP 12 tir3 Docket No. 50-358 Cincinnati Gas and Electric Company ATTN:

Mr. Earl A. Borgmann Vice President Engineering Services and Electric Production 139 East 4th Street Cincinnati, OH 45201 Gentlemen:

Enclosed is IE Bulletin No. 79-23 which requires action by you with regard to your pcwer reactor facility 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, Mames G. Keppler Director Enclosure IE Euiletin No. 79-23 cc w/ encl:

Mr. J. R. Schott, Plant Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Harold W. Kohn, Power Siting Commission Citizens Against a Radioactive Environment Helen W. Evans, State of Ohio

\\o49 \\00 70092701Ib

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 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 in n tigation 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 a6aufacturer's findings and recommendations regarding the above problem are described below:

"A potential problem can exist if the ne thh primary windings of the excitation p DUPLICATE DOCUMENT to as the control power transformer (CPT Entire document previously entered into system under:

cc/og22 0/oll ANo f P*9o":

6 1049 101

__