Patent Number: 051924943
Section: abstract

A penetration (51) through the bottom of a pool in the reactor containment below a reactor vessel is protected against the effects of a core meltdown, by the penetration (51) being surrounded by a pipe (60) having an inlet (61) located below the surface (31) of the water and above the highest level (41) which the bed (4) of granulate formed by the descending molten core material could be expected to reach. The pipe (60) has an outlet (62) at its lower end, located in the bed (4). The gap (64) between the penetration (51) and the pipe (60) is covered by a screen (7) which prevents granulate from entering. Granulate is also prevented from entering the outlet (62). The pool water flows in through the inlet (61), down through the gap (64), out through the outlet (62) and into the particle bed (4) where the water is vaporized and rises through the bed without obstructing the flow of water through the gap for cooling the penetration. The pipe (60) prevents contact between the particle bed (4) and the penetration (51). Said pipe is cooled by the flow of water through the gap (64) and promotes improved cooling of the particle bed.