A Review of Wear Scar Patterns of Nuclear Power Plant Components

To date, almost all the studies related to component damage have been concerned primarily with dynamic interactions at the interface of contacting components and the subsequent damage due to mechanical wear. Based on the results of examination of a large assortment of photo-micrographs taken from worn reactor components and worn specimens from a broad range of test facilities, it appears that, in many cases, mechanical wear is only a secondary contributing mechanism. With the exception of special cases where severe flow-induced vibration might have occurred, such as in some condensers and primary heat exchangers as well as in the U-bend and inlet regions of some earlier steam generators, resulting in severe component interactions causing substantial wear damage, erosion, corrosion, impacting and perhaps cavitation would seem to be the primary contributing mechanisms.