Load carrying capacity of a reactor vessel head under molten core slug impact final report including recent experimental findings

The load carrying capacity of the pressure vessel head to withstand a postulated in-vessel steam explosion has been investigated. Former results have been confirmed and extended. For a quite conservative reference case the mechanical energy release which the head can carry turns out to be at least 1 GJ. The mechanical energy release from in-vessel steam explosions postulated can be expected to be significantly lower, and therefore will not rupture the vessel head and not endanger the containment integrity.