ML19338D604
| ML19338D604 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/17/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8009230549 | |
| Download: ML19338D604 (2) | |
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TENNESSEIE VALLEY AUTHORITY CHATTANOOGA, TENNESSEE 37401 400 Chestnut Street Tower II Septercer 17, 1980 4
Director of Nuclear Reactor Regulation Attention:
Hr. A. Schwenoer, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Comaission Washington, DC 20555 Dear Mr. Schwencers-i In the Hatter of the Application of
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Desket Nos. 50-327 J
Tennessee Valley Authority
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50-328
Reference:
Letter from A. Schwencer to H. G. Parris dated September 4,1980 i
Supplement No. I of the Safety Evaluation Report for the Sequoyah Nuclear Plant as transmitted to TTA by the m ferenced letter. In section 8 3 1,
" Diesel Generator Reliability," there is a requirement to m place all the j
turbocharger drive gear assemblies with a heavy duty drive gear assembly at the first mfueling outage.. The stated purpose of this mquirement is to improve the reliability and availability of the diesel generators and to reduce problems associated with no-load and light-load operation.
TVA takes exception to the mquirement to perform a blanket changeout of all turbocharger drive gear assemblies at the first refueling outage.
The reasons for this exception and~ an alternate proposal are presented below.
TVA has been aware of the limited life of turbocharger" drive gear anse:tlies en Geteral Motors Corporation, Electro-Motive Division (Gi-EMD)
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engines. GWDC recommends that the turbocharger drive gear assemblies be changed out after 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> of light-load operation. TVA has incorporated this moomr.endation into the diesel generator maintenance program. The amount.of no-load and light-load operation is admini-stratively controlled.
TTA has consider 1mble emperianos with 96 588 turbocharger drives. The Breums Ferry Nuclear Plant diesel generators have identical termy drives as Sequoyah and have been operating for over eight years.~ TVA has not experienced any problems with the Browns 5/orry drive assemblies.
GM-De reconnends that the drive gear assembly be replaced afterj200 hours of light-load operation. 7TA has incorporated this reocamendatica into the diesel generator maintenance program..By following the vender-established lifetime recessiendation, changeout would proceed in a more l
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Director of Nuclear Reactor Regulation September 17, 1980 j.-
orderly fashion. -Based on previous experience, TVA does not expect to exceed the 200-hour' limit at Sequoyah for at least seven years. In eight years the Browns Ferry unit 1= diesel generators have accumulated enly 450
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hours total operation per diesel generator.
TVA plans to change 'out two turbogenerator drive units per refueling outage. This schedule would mault in considerable savings because TVA would purchase just two new turbocharger drive units instead of eight.
The new units cost approximately $145,000 each. At each refueling outage, two units would be changed out with heavy duty units. The~ original units
-that have been pulled would be sent back to Gi-EMD for refit with the heavy 1
duty gears. These units, when mturned, wculd be used to swap out with the next scheduled units. The proposed schedule woulo minimize problems with procumment and/or de3ivery of parts and servios.
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Based on TVA's own experience and GM-EMD recosamndations regarding turbo-charger drive gear assemblies, TVA has proposed an alternate replacemer.L schedule. This proposal would limit turbocharger operation at light loads to less than'200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> with changeout occurring on a two assembly per refueling outage basis... Pleano evaluate this proposal as to its seceptability as an alternative to the blanket changeout recommended at first refueling outage.
Very truly yours, i
TENNESSEE VALLEY AUTHORITY N
. M. Mills, Mi mager Nuclear Regula<; ion and Safety Sworn to d subscribed before me 1980 this day of Gaoh K A 4/A X Botary Publio
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