Steam explosion driven impact of molten core material on the upper pressure vessel structures of a PWR

Energy assessments are presented for a molten fuel slug impact on the upper pressure vessel structures. In order to obtain more definite results, also the momentum transfer is discussed from the molten fuel slug to the vessel head. Here the interaction between the slug flow and the collapsing upper core structures play an important role. Estimates are presented for the slug resistance of the vessel head. Finally, model experiments are described which are indispensable for a reliable solution of this problem. (author)