In the development of the European pressurized water reactor (EPR), a new, challenging safety goal is the requirement to restrict the consequences of even severe accidents to the immediate vicinity of the plant.

To deal with the consequences of a severe accident means to deal with different phenomena of an assumed core meltdown accident. Specific controlling and mitigating measures and dedicated design features that will cope with these phenomena are intended to be incorporated into the safety design of the EPR.

To prove that the assumptions made by the EPR project are in line with the results of research and development, a first cooperation between Forschungszentrum Karlsruhe, the vendor Siemens Company, and a consortium of utilities was started in 1993 and produced provisional results in 1995. Further investigations of severe accident phenomena are necessary to verify the controlling and mitigating design features of the EPR.