Experimental programs and facilities for ASTRID development related to the Severe Accident Issue

In support to the development and qualification of severe accident codes and mitigation devices for ASTRID, a comprehensive experimental programme has been designed. It encompasses in-pile experiments, prototypic corium experiments and simulant material tests. In particular, in-pile experiments are necessary to study the behaviour of large pins, of the ASTRID CFV heterogeneous subassemblies during severe accident transients and of in-core mitigation devices. Corium experiments are planned in the PLINIUS facility at small and medium scale and a new large scale facility, FOURNAISE, will be needed mainly for FCI, corium relocation and core catcher issues. This facility would be able to melt and study a few hundreds of kilograms of uranium-based prototypic corium. Prototypic tests will be complemented by new low temperature simulant material experiments e.g. for core catcher thermalhydraulics and jet ablation. (author)