ML19246B735
| ML19246B735 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 06/28/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Davidson D CLEVELAND ELECTRIC ILLUMINATING CO. |
| References | |
| NUDOCS 7907180403 | |
| Download: ML19246B735 (1) | |
Text
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gk UNITED STATES PDR o,
NUCLEAR REGULATORY COMMISSION y }, ~,,f( j d/
c REGION lil
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799 ROOSEVELT ROAD
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o, GLEN ELLYN. lLLINOIS 60137 JUN 2 81979 Docket No. 50-440 Dqcket No. 50-441 c..
The Cleveland Electric Illuminating Company ATTN:
Mr. Dalwyn R. Davidson Vice President - Engineering P. O. Box 5000 Cleveland, OH 44101 Gentlemen:
The enclosed IE Circular No. 79-12, is forwarded to you for infor-mation. No written response is reqtired.
Should you have any questions related to your understanding of this matter, please contact this office.
Sincerely, W ; b gs> AL
(/JamesG.Keihfer f
Director
Enclosure:
IE Circular No. 79-12 cc w/ encl:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR N3IC TIC Harold W. Kohn, Power Siting Commission Mr. Daniel D. Wilt, Attorney
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7907110403 364 19@
U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III L.
June 28, 1979 IE Circular No. 79-12 (7906210065)
POTENTIAL DIESEL GENERATOR TURBOCHARGER PROBLEM Descripticn of Circumstances:
The Electro-Motive Division (EMD) of General Motors Corporation has recently identified a potential failure mode of turbochargers used on EMD diesels in nuclear plant standby service.
When an engine is in the nor=al standby mode, the lubricating oil temperature is maintained at about 115 degrees F and the circulating oil pump supplies warm oil to the turbocharger bearings at a flow rate of about 2 gpm.
Since the.. ital oil pu=p flow rate is 6 gpm, 4 gpm is also circulated, via a 30 psi relief valve, through the lube oil filter and cooler which serves to keep tLe entire accessory lubricating oil system primed to support a fast start.
If a power outage occurs, the oil circulating pu=p may stop 5 to 10 seconds before the engine receives a start signal; but the main bearing and piston cooling pu=p will i==ediately receive oil from the primed lube oil filter-cooler sys. tem thus providing a rapid buildup of engine lube oil pressure throughout the engine bearing and turbocharger systems.
A potential problem occurs, however, if th2 diesel engine receives a repeat rapid start within a minimum of 15 minutes and a maximum of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> after a shutdown from a previous run in which the engine has reached full operating temperature.
If, for example, the engine had been operated for about I hour at full load, the lube oil te=perature would be at about 200 degrees F at time of shutdown. Under these circumstances, the full 6 gpm output of the circu-lating pu=p will flow only to the turbocharger bearings because of the lower viscosity of the hot lubricant. At this te=perature, the circulating pump pressure
".11 not reach 30 psi.
Until the lube oil cools to about 160 degrees 7 no of will be supplied via the relief valve to the equipment rack for the first 2 to 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> after engine shutdown. During this cooling period some of the oil contained in the cooler and filter will drain back to the engine su=p via the lube oil scavenging pu=p, and some of the oil from the strainer box rill oe drawn into the cooler by the system vacuum that develops. The result is that when a repeat fast start oc time frame after a hot shutdown, l'
! DUPLICATE DOCUMENT engine damage.
In the worst case c ; '
actually reach operating speed, 90(
Entire document previously entered established at the turbocharger thz iinto system under:
of the bearing metal so that cumula would result in a turbocharger felJ ANO No. of pages:
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