05000321/LER-1979-104-03, /03L-0:on 791216,w/reactor in Shutdown Mode, Standby Diesel Svc Water Pump Motor 2P41-C002 Tripped.Caused by Mechanical Overload.Bolts Associated W/Pump Had Broken Loose Causing Misalignment of Pump Shaft.Pump Rebuilt

/03L-0:on 791216,w/reactor in Shutdown Mode, Standby Diesel Svc Water Pump Motor 2P41-C002 Tripped.Caused by Mechanical Overload.Bolts Associated W/Pump Had Broken Loose Causing Misalignment of Pump Shaft.Pump Rebuilt

ML19260C747
Person / Time
Site:	Hatch
Issue date:	01/02/1980
From:	Nix R GEORGIA POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19260C745	List: 05000321/LER-1979-104, Forwards LER 79-104/03L-0 05000321/LER-1979-104-03, /03L-0:on 791216,w/reactor in Shutdown Mode, Standby Diesel Svc Water Pump Motor 2P41-C002 Tripped.Caused by Mechanical Overload.Bolts Associated W/Pump Had Broken Loose Causing Misalignment of Pump Shaft.Pump Rebuilt
References
LER-79-104-03L-01, LER-79-104-3L-1, NUDOCS 8001080576
Download: ML19260C747 (3)

LER-1979-104, /03L-0:on 791216,w/reactor in Shutdown Mode, Standby Diesel Svc Water Pump Motor 2P41-C002 Tripped.Caused by Mechanical Overload.Bolts Associated W/Pump Had Broken Loose Causing Misalignment of Pump Shaft.Pump Rebuilt

Event date:
Report date:
3211979104R03 - NRC Website

text

RC FORM 30G U. S. NUCLE AR REGULATORY COMMISSION 11l LICENSEE EVENT REPORT CONTRot OLbCK:

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8 60 68 OOCKET NUYDER od 63 EVENT DATE 74 JS REPORT DATE 80 EVENT DESCRIPTION AND PROCABLE CONSEcuENCES h 10121 l With the reactor in the shutdown mode, while performinq procedure HNP-1-3301, Diesel I

O l3l [. Generator Manual Start, 2P41-C002, Standby Diesel Service Water Pump, tripped.

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[ Technical Specification 3.5.J.2 was not reouired due to the plant being shutdown 1

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Public health and safety were not affected by this incident.

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40 46 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l The cause of the 2P41-C00? motor trip was due to a mechanical overload.

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Georgia Pcwcr Company Plant E. I. Hatch Baxley, Georgia 31513 Reportable Occurrence Report No. 50-321/1979-104.

Cause Description and Corrective Actions (cont)

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have been caused by the misalignment of the pump shaft. The direct cause of the deterioration of bolts _ is not known at this time.

The deterioration, of the bolts, appears to have been caused by electrolysis. An analysis is ting made to determine the direct cause of deterioration. Aa update report will follow when an analysis is determined. The 2P41-C002 is a standby service water pump, shared by both units, and the only pump of its type at Plant Hatch.

The pump stages bolts, bowl bearings, lower seal ring and the pump shaft were replaced and the pump returned to service.

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REPORT Georgia Power Company Dhh D []@{ff

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Baxley, Georgia 31513 Reportable Occurrence Report No. 50-321/1979-104.

~ - On December 16, 1979, with the reactor in the shutdown node, the 2P41-C002, Standby Diesel Service Water Pump, motor tripped. 'The c.iuse of the motor

. tripping was due to a mechanical overload.

Upon investigation of the problem, it was discovered that a number of the bolts used to assemble the suction bell, internediate bowls and discharge case of the pump 1.'d deteriorated and broken loose causing misalignment of the pump shaft.

There was also evidence of wear to the seal rings, bowl bearings and the pump shaft.

The direct cause of the deterioration of the bolts is net known at this time.

The deterioration, of the bolts, appears to have been ceased by electrolysis.

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An analysis is being made to determine the cause of deterioration. The cause of wear to the pump shaf t, seal rings amd bowl bearings was due to pump shaft misalignment.

The pump was rebuilt, meeting all operating requirements and returned to service.

There are other pumps of a similar design located in the general area with this pump'.

There has not been a similar problem with any of these pumps.

This was not a repetitive occurrence. The 2P41-C002 is the standby service water pump, shared by both units, and the only pump of its type at the plant site.

A follow-up report will be submitted when the cause of the bolt deterioration is determined.

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