ANALYSIS AND NUMERICAL-SIMULATION OF THE THERMOHYDRAULIC BEHAVIOR OF A HEAT DISSIPATING DEBRIS BED DURING POWER TRANSIENTS

A mathematical model for the description of the transient behaviour of a liquid saturated core debris bed with internal heat dissipation is formulated and solved numerically. The development is supported by the findings of an out-of-pile investigation of the relevant phenomenology. Furthermore the data from the Sandia Laboratories D10 in-pile test as well as from the first European in-pile experiment designed to study, in the frame of the Post Accident Heat Removal Programme, the long term coolability of such a bed, are used for the validation of the model.