COMPARISON STUDY OF 12CR18NI10TI STEEL MICROSTRUCTURE FROM FACE AND RIB REGION OF A FUEL ASSEMBLY HEXAGONAL SHROUD IRRADIATED IN THE BN-350 REACTOR

Abstract

The results of comparison investigations of both microstructure and properties of 12Cr18Ni10Ti steel – the material of CC-19 fuel assembly shroud irradiated up to 26.5 dpa – are presented. Specimens were cut from the same height level from face and rib regions of the shroud. The techniques of transmission electron microscopy, metallography and microhardness measurement were used. It was found that the rib’s vacancy swelling is greater by several fold than the face one, the possible reasons of this phenomenon are discussed.