Comparison between direct and indirect cooling core catchers

The European nuclear design requirements, which should be satisfied by nuclear reactors in Europe, usually recommend a so called core catcher, which is a molten core ex vessel cooling facility, to manage a severe accident at a nuclear reactor. Two different types of core catcher concepts are compared to determine their abilities to manage severe accidents and cool core melts. The study reveals that direct cooling is better for cooling capacity and is convenient to construct, while indirect cooling is better for the management of a severe accident