ASTECv2/MEDICIS computer code investigation of influence of water content and carbon dioxide content in the concrete on the kinetics of molten corium–concrete interaction

This investigation was done in the frame of SARNET2 European Network of Excellence on Severe Accidents project (6-th Framework Program of the European Commission), joint program activity JPA-2, WP6-4. ASTECv2/MEDICIS computer code was used to simulate the ex-vessel corium–concrete interaction cases. This code, jointly developed by the IRSN (France) and GRS (Germany) for simulation of severe accidents, is now considered as the European reference simulation tool. As a reference nuclear power plant for these ASTECv2/MEDICIS calculations the VVER1000 reactor type was used. in goal of this paper is to investigate the influence of water content (H2O) and the content of carbon dioxide (CO2) in the concrete on the kinetics of molten corium–concrete interaction (MCCI) between the molten corium and reactor basemat concrete. In this paper, there are investigated different concentrations of H2O and CO2 in the concrete interacting with the corium poured after reactor vessel failure during a severe accident in VVER1000 nuclear power plant.