The possibility of refrigerating corium outside the vessel: the MACE and MCCI experiments

The containing enclosure of a nuclear power station is the last barrier to avoid fission products being released to the outside in the event of an accident. Independent evaluations made by the CSN on the level 2 APS have shown up a dominating containing fault in various Spanish power stations involving penetration of the reactor cavity slab by the interaction between corium and concrete. This article analyses the feasibility of a serious accident management strategy which aims to avoid this type of containment failure. The strategy consists of pouring water on the corium deposited in the slab in order to cool it and halt the concrete ablation. (Author)