ML19208C618
| ML19208C618 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 09/12/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stampley N MISSISSIPPI POWER & LIGHT CO. |
| References | |
| NUDOCS 7909270146 | |
| Download: ML19208C618 (1) | |
Text
.
,pn proo
'o UNITED STATES NUCLEAR REGULATORY COMMISSION
- E REGION 11 101 MARIETTA ST N.W.. SUITE 3100 s
MNEk g
ATLANTA. OEORGIA 30303 In Reply Refer To:
SEP 121979 RII:JPO 024f6 ^-
M 17 Mississippi Power and Light Company Aten:
N. L. Stampley Vice President of Production P. O. Box 1640 Jackson, Mississippi 39205 Gentlemen:
Enclosed is IE Bulletin 79-23 which requires action by you with regard to your power reactor facility (ics) 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, V
James P. O'Reilly Regional Director
Enclosures:
1.
List of IE Bulletins Issued in the Last Six Months
Accession No. 7908220104 SSINS No.:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHING 10N, 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 investigation and testing by the licensee revealed a design error on both the / and B EDGs which resulted in overheating of the Exciter Power Transformers (EPTs) at sustained high load operation.
The rollowing 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 Cyclec-60 KVA 15 Im ulation-4160 V The manufacturer's findings and reconne are described below:
DUPLICATE DOCUMENT "A potential problen can exist if ti-ne the primary windings of the excitati:n j Entire document previously to as the control power transformer (CP' entered into system under:
N$hhbf ANO No. of pages:
1050 127 e+