DHCVIM: A direct heating containment vessel interactions module: Applications to Sandia National Laboratory Surtsey experiments

Direct containment heating is the mechanism of severe nuclear reactor accident containment loading which results from transfer of thermal and chemical energy from high temperature, finely divided, molten core material to the containment atmosphere. The Direct Heating Containment Vessel Interactions Module, DHCVIM, has been developed at BNL to mechanistically model the mechanisms of containment loading resulting from the direct heating accident sequence. The calculational procedure is being used at present to model the Sandia National Laboratory 1/10th-scale Surtsey direct containment heating experiments. The objective of the code is to provide a test bed for detailed modeling of various aspects of the thermal, chemical and hydrodynamic interactions which are expected to occur in three regions of a containment building: reactor cavity, intermediate subcompartments and containment done. Major emphasis is placed, at present, on the description of reactor cavity dynamics. This paper summarizes the modeling principles which are incorporated in DHCVIM and presents a prediction of the Surtsey Test DCH-2 which was made prior to execution of the experiment.