Phenomena in the interaction among a Core Melt and Protective and Sacrificial Materials

In a postulated core meltdown accident in a light water reactor there are b ound to be interactions, in the ex-vessel phase, among the core melt and th e structural materials within and below the reactor cavity. In existing pla nts, these structural materials normally are structural concrete, while fut ure, evolutionary reactor lines are to have sacrificial and protective mate rials specially designed for this hypothetical case. To add to the state of knowledge about the phenomena occurring, experiments need to be conducted under conditions as realistic as possible. Within the research programs funded by the European Union, the German Federal Ministr y for Economics, and the German nuclear power plant operators, experiments on a laboratory as well as an industrial scale on these problems are being carried out in the two projects called CORESA (COrium on REfractory and SAc rificial materials) and ECOSTAR (Ex-vessel COre melt STAbilization Research ). The experiments are accompanied by an extensive analytical theoretical prog ram also serving to advance and validate computer codes on the problems und er investigation. The projects, which are carried out with international European participati on, are expected to allow a concept to be developed for managing postulated accident scenarios involving core meltdown for innovative nuclear power pl ants, and to provide findings on risk evaluation of plants now in operation so as to further develop accident management measures.