ML19208C725

From kanterella
Jump to navigation Jump to search
Forwards IE Bulletin 79-23, Potential Failure of Emergency Diesel Generator Field Exciter Transformer. Action Required
ML19208C725
Person / Time
Site: Trojan File:Portland General Electric icon.png
Issue date: 09/12/1979
From: Engelken R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To: Goodwin C
PORTLAND GENERAL ELECTRIC CO.
References
NUDOCS 7909270282
Download: ML19208C725 (1)


Text

pa a'c,

u

'o UNITED STATES

,lL NUCLEAR REGULATORY COMMISSION

'l g' *; A)4)1' gj llEGION V o,

is,f,f 1990 N. calif ORNI A fiOULEVAllD

'g.

" %,t '

SUITE 207, WAl. NUT CR E E K PLAZA e,,,,

WALNUT CREE K, calif ORNIA 9%%

September 12, 1979 Docket flo. 50-344 Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attention: Mr. Charles Goodwin Assistant Vice President 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 have questions regarding this Bulletin or the actions required of you, please contact this office.

Sincerely, flS?

db5-R. H. Engelken Director

Enclosures:

1.

IE Bulletin flo. 79-23 2.

List of IE Bulletins Issued in the Last Six Months cc w/ enclosures:

C. P. Yundt, PGE F. C. Gaidos, PGE 1049 201 7909270 787

Accession fio. 7903220104 SSINS fio.:

6820 UNITED STATES frJCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION Afl0 ENFORCEMENT WASHIf4GTON, D.C.

20555 September 12, 1979 IE Bulletin No. 79-23 POTENTIAL FAILURE OF EMERGEi4CY DIESEL GENERATOR FIELD EXCITER TRANSFORMER De_scriotion of Circumstar.ces:

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 resultec' in overheating of the Exciter Power Transformers (EPTs) at sustained high laad operation.

The following nameplate data applies to the equipment installed at Turkey Point:

Emergency Diesel Generator General Motors (Electro-Motive Division) flodel EMD-999-20 Engine-turbocharged, 2 cycle, EMD design 20-645E4 Generator-EllD-design Model A-20 Exciter Power Transformer GE-single phase Model-9T24Y1004 Serial-MD Cycles-60 KVA 15 Insulation-4160 V The manufacturer's findings and recommendations regarding the above problem are described below:

"A potential problem can exist if the nn.ral of the generator and the neutral of the primary windings of the excitatic to as the control power transformer (

DUPLICATE DOCUMENT between the neutrals, or a connectior are equally undesirable conditions.

Entire document previously ditions exist, high circulating curr(

entered into system under:

currents may exceed transformer ratir Silure.

ANO

~/@$32b/C4/

no or pases:

f 10e 202