ML20202J004

Forwards Info Re Diesel Generators,Per Request.License Conditions,Established in Mar 1985 to Forewarn of Impending Bearing Damage,Failed to Detect Recent Failures

ML20202J004
Person / Time
Site:	Fermi
Issue date:	12/11/1985
From:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
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References
FOIA-86-244 NUDOCS 8607170006
Download: ML20202J004 (4)

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morso str.vus SOUCLEAR REGULATORY C0hW18840N E .. nemen m stem mLLvw,su.twees sess, December 11, 1985 NOTE TO: James G. Keppler, Regional Administrator, Region III FROM: A. Bert Davis Deputy Regional Administrator

SUBJECT:

FERMI DIESEL GENERATDRS Information on the Ferst diesel generators is forwarded as requested.

A. Bert Davis Deputy Regional Administrator

Enclosure:

As Stated 1

1 8607170006 860709 PDR FOIA PUNTENN86-244 PDR

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i During a surveillance run last January Emergency Diesel Generator (EDG)

No. 11 tripped due to low oil pressure. The investigation revealed several damaged bearings on the upper crankshaft which were attributed to lack of lubrication during engine starts. Some upper crankshaft ,fournals were also damaged. A modification had been Installed prior to the failure which was supposed to lubricate the upper bearings during engine starts. As a result, the licensee had discontinued manual prelubrication of the engines. An inspection of the other three EDG's revealed damage had also occurred on EDG No. 12. While no damage was found on EDG's No. 13 and No. 14, the inspectors -

noted a peculiar " frosted" appearance on the bearing of EDG No. 14. That issue was never resolved last winter.

A review of the operating and maintenance histories of all four engines failed i

to explain why Nos.11 and 12 had suffered severe bearing damage while Nos.13 and 14 had not.

r The licensee replaced EDG No. 11 upper crankshaft and all its associated i bearings. EDG No. 12 upper crankshaft bearings were also replaced. A license condition was established which required the licensee to analyze monthly oil samples for metal content, inspect the oil filters quarterly and perform a main bearing gap check if a specific number of particles were found, and p2rform a main bearing gap check after 20 " dry" starts or 18 months whichever cccurred first, During a 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> surveillance run last November on EDG No.13, abnormal coises were heard by an operator after approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and the engine a.

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1 cas tripped. The investigation revealed upper crankshaft damaged bearings again. EDG No. 14 was opened and, while no damaged bearings were found, the inspectors feel that the condition noted last February has deteriorated. A rougher surface appears in the original " frosted" surfaces and also on new bearing surfaces. Scoring and much more dirt was also evident. Slight signs of distress were noted in some of the grooving.

Reluctantly the licensee opened EDG No.11 and several upper crankshaft main bearings were found in different stages of distress. This damage was not oxpected, and as a result EDG No. 32 was opened. The bearings on EDG No.12 were found in good condition although there are some signs which need investigation.

The licensee has again contacted the vendor and Failure Analysis Associates, Inc. to investigate the problem. Both were involved in last winter's 1 investigation. The NRC is using Franklin Research Center (FRC) in  ;

Philadelphia as its main consultant, and bearing lube oil, bearing conditioner, and lapping compound samples have been taken to the FRC for analysis. The NRC and the licensee are also pursuing what differences in operating, maintenance, material. lube oil, etc., there may exist between the type of diesels at Formt 2 vs the same vendor diesels at other nuclear facilities.

(Duane Arnold, Prairie Island) s -

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It should be noted that the license conditions established last March to fsrewarn of impending bearing damage failed to detect the recent failures.

The oil analysis results up to the month before the failures showed no abnormal results. The filter inspections also failed to warn of an impending failure, as did the bearing gap check performed at the time EDG No.11 was cpened this month.

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