ML19262B030
| ML19262B030 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 10/25/1979 |
| From: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-23, NUDOCS 7912110439 | |
| Download: ML19262B030 (1) | |
Text
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THE CINCINNATI GAS & ELECTRIC COMPANY
~
CIN CIN N ATI OHIO 4 5201 October 25, 1979 E. A. BO RG M AN N wc t *=r s'or NY 4
U.S. Nuclear Regulatory Cc:,.ission Region III 799 Roosevelt Road Glen Ellyn, Illinu _ 60137 ATIN: Mr. James C Ecp"ler Regional Director RE:
hM. H. ZIMIER NUCLF>R PoliER STATION - UNIT 1 IE BULLETIN 79-23, POTENTIAL FAILURE OF DIERGENCY DIESEL GENERATORS FIELD EXCITER TRANSFORMERS DOCKET 50-358, W.O. 57322, JOB E-5590, ITBI # 2676 Gentlemen:
This Ictter is in response to I.E. Bulletin #79-23 concerning potential failure of emergency diesel generator field exciter tnnsfomers.
First, in response to item 1 of the referenced I.E. Bulletin, we have re-viewed this problem with the diesel generator vendor. The problem described by the bulletin does not exist at the Wm. H. Zimmer Nuclear Power Station - Unit 1.
He excitation power transfomer primary winding does not have a neutral connection.
The winding is connected phase to phase.
In addition, 3 potential transfomer primary windings arc connected in wye with the neutral grounded. However, the generator neutral is grounded through a high resistance which provides adequate limitation on the flow of circulating currents induced by hamonic voltages.
In response to item 2, the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> load test described in the bulletin and in Regulatory Guide 1.108, revision 1 will be perfemed during preoperational testing of the emergency diesel generators. He test is tentatively scheduled for the first quarter of 1980.
We believe this information provides a complete response to the subject I.E.
Bulletin.
Very truly yours, THE CINCINNATI GAS S ELECTRIC CCTIPANY
((
pW-E.A. BORGbteN, SENI0IVICE PRESIDENT WPC/kjd cc:
U.S. Regulatory Commission Office of ISE R.F. Scheibel C.W. Beringhaus
)
3 2 030 R.E. Cotta B.K. Culver i:E:j$il 0CT 2 91979
" C 8'i" * ""
J.R. Schott J.D. Flynn 7912110
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