Current understandings of accident sequences and key phenomena in LMFBR core disruptive accidents

In this paper, trends and current understandings of the key sequences and phenomena in core disruptive accidents (CDAs) are discussed with emphasis on recent advances in the research and development. Based on the current level of understandings and technologies on CDAs, a best-estimate safety analysis is now possible for intermediate-sized reactor plants by taking into account various inherent mechanisms to control and mitigate the accident progression. From these achievements, the future perspectives of the CDA issues are discussed by addressing approaches toward successful in -vessel accommodation and future research needs. (author)