Two EU-funded tests in VULCANO to assess the effects of concrete nature on its ablation by molten corium

In order to understand the effects of concrete properties on corium-concrete interaction, it has been chosen to perform new VULCANO experiments with concretes having a different composition from the classical silica-limestone concretes. Firstly, a concrete has been made using cement clinker (calcinated limestone) instead of limestone (calcium carbonate) in order to obtain a material forming a melt with the same composition as the melt from a previously-tested concrete with limestone rich aggregates, but in which the aggregates are not destroyed before melting. This was the first VULCANO test funded with the SARNET2 grant. It showed an anisotropic ablation, typical of the silica-rich concretes, proving that molten concrete composition was not the cause of the transition from isotropic to anisotropic ablation. Then, the ferro-siliceous sacrificial concrete used in Olkiluoto 3 (EPR) reactor pit has been studied within the PLINIUS FP6 Transnational Access project. This new concrete interacted with corium, following a similar experimental procedure. Here also, an anisotropic ablation has been observed.