Nuclear reactor installation including a core catching apparatus

Claim 1

A nuclear reactor installation having an H 2 O containing coolant associated therewith and comprising: a nuclear core vessel; a nuclear core enclosed within said vessel and including structural metallic components and nuclear fuel; and a core catching apparatus disposed below the nuclear core, said core catching apparatus consisting of a container of highly temperature resistant materials and forming a pan-like melt-through barrier for receiving and containing the components of the nuclear core including the nuclear fuel during a core-melt-down accident; and a protective top layer disposed within the container and supported in spaced relationship above the floor of said container, and adapted to be penetrated by the molten core components flowing from the nuclear core during a core melt-down accident, said top layer being chemically inactive with regard to H 2 O, and having a lower density than the metallic components of the core, so as to overlay, during such core melt-down accident, the metallic portion of the molten core but having a higher density than water and being present in an amount sufficient to isolate the metallic components of the core melt in the container and protect them from being connected by water thereby preventing the formation of hydrogen.