ML17318A444
| ML17318A444 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/05/1979 |
| From: | Hunter R INDIANA MICHIGAN POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-23, NUDOCS 7911230051 | |
| Download: ML17318A444 (4) | |
Text
INDIANA R MICHIGAN POWER COMPANY P. O. BOX 18 BOWLING GREEN STATION NEW YORK, N. Y. 10004 November 5,
19?9 AEP:NRC:00283 Donald C.
Cook Nuclear Plant Unit Nos.
1 and 2
Docket Nos.
50-315 and 50-316 License Nos.
DPR-58 and DPR-74 IE Bulletin No. 79-23 Nr. James G. Keppler, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Nr. Keppler:
This letter and its attachment respond to your letter of September 12, 1979 which we received on September 18, 1979 and which transmitted to us IE Bulletin No. 79-23 entitled "Potential Failure of Emergency Diesel Generator Field Exciter Transformer."
Very truly yours, v'.l
. S. Hunter Vice President cc:
USNRC, Office of I 8
E - Washington, D.C. 20555 R.
W. Jurgensen J.
E.
Dolan D. V. Shaller -Bridgman G. Charnoff R.
C. Callen
Mr. James G. Keppler, Director AEP:NRC:00283 bc:
S. J. Milioti/J.I.Castresana/G.
M. Gurican R.
F. Hering/S.
H. Steinhart R.
F. Kroeger H.
N. Scherer, Jr./J.
M. Intrabartola/T.
E. King J. Stietzel-Bridgman NRC Region III Resident Inpsector -Bridgman D. Migginton - OSNRC - Bethesda DC-N-6015.3.1 AEP:NRC:00283
ATTACHMENT TO AEP:NRC:002S3
Our response is given below for each of the two action items contained in the Bulletin.
RESPONSE
TO ACTION ITEM 1:
The potential transformers connected to the diesel generator and to the diesel generator busses are connected grounded wye primary and grounded wye secondary.
The diesel generator is connected wye and is grounded through a low impedance fault limiting resistor.
The neutrals of the diesel generator and the potential transformers are connected
- together, which is acceptable since no low impedance path for triple harmonics exists.
Since the present neutral con-nection system is acceptable, no corrective actions are necessary.
RESPONSE
TO ACTION ITEM 2:
The Uni,t 2 AB and CD diesel generators were operated for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at 3850 KW and at least 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> at 3500 KW as part of the pre-operational testing prior to Unit 2 startup.
3850 KW is the 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> rating and 3500 KW is the continuous rating of these diesbl generators.
The tests were completed on January 30, 1978 for. the Unit 2 AB diesel and January 14, 1978 for the Unit 2 CD diesel.
Operation of the engine and generator cooling system was acceptable.
The units were loaded by paralleling with the auxiliary bus and the resulting voltages and frequencies were with-in acceptable limits.
The Unit 1
AB and CD diesel engines are identical to the Unit 2 AB and CD diesel engines.
The Unit 1
AB and CD diesel engines have not been test operated above their rated load of 3500 KW.
The most recent maintenance verification operational tests were for a period of at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
A minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the test interval was at rated load and for the remainder of the time, the load ex-ceeded half load of 1750 KW.
These engines have demonstrated their ability to perform for long term operation.
We will perform the re-quested 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at 3850 KW, the.2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> rating, and 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> at 3500 KW, the continuous rating, during the next refueling outage for Unit 1;