ENS 47347

v t e ENS Event
04:00 Oct 11, 2011
Title	Part 21 Notification - Emergency Diesel Generator Piston Delamination
Event Description	Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 08/12/11 upon receipt of four piston assemblies returned from Perry Nuclear Plant. It was reported that Perry had performed a maintenance activity whereby they replaced four of their piston assemblies with four refurbished pistons provided by ESI. Following installation of the replacement pistons, it was found that large portions of the tin plating were flaking or smearing off. The evaluation was concluded on 10/11/11 and determined the piston tin plating delamination to be a reportable defect as defined by 10CFR21 . The delamination was attributed to residual oil impregnated in the ductile cast iron base material of the skirts. The piston assemblies had previously been in service on the emergency diesel generators and were later refurbished by ESI in 2007. A portion of the refurbishment activity consisted of re-tin plating the piston skirts. ESI is not aware of any absolute methods for ensuring all oils have been removed (or at least to the point that it will not interfere with tin plating adhesion). As a result of this finding, it is ESI's recommendation that piston skirts which have been in service should no longer be re-tin plated. ESI Internal Report Number: 10CFR21-0103, Rev. 0 Potentially affected power plants: Perry, River Bend, Comanche Peak, and Catawba

ENS 47347 +/-
Where
Engine Systems, Inc Rocky Mount, North Carolina (NRC Region 1)
Organization:	Engine Systems, Inc
Reporting

10 CFR 21.21
Time - Person (Reporting Time:+157.32 h6.555 days <br />0.936 weeks <br />0.215 months <br />)
Opened:	Tom Horner 17:19 Oct 17, 2011
NRC Officer:	Mark Abramovitz
Last Updated:	Oct 17, 2011
47347 - NRC Website
v • d • e

v t e Emergency Notification System
Engine Systems, Inc with 10 CFR 21.21
WEEKMONTHYEAR2011-06-16T16:00:00 [Table view]
[ENS list for Engine Systems, Inc]

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