Molten fuel-coolant interactions resulting from power transients in aluminium plate/water moderated reactors.

Abstract

The behaviour of two reactors SL1 and SPERT D12 which underwent fast nuclear power transients prior to core destruction by a molten fuel-coolant interaction (MFCI) has been analysed and the results compared with measured data. The calculated spatial melt distribution and the mechanical work done during the events leads to high (approx 250 kJ/kg) conversion efficiencies for this type of interaction when compared with molten drop experiments. A simple model for the steam explosion using static thermodynamic properties of high temperature and pressure steam is used to calculate the dynamics of the reactors following the MFCI.