ANALYSIS OF A HYPOTHETICAL CRITICALITY ACCIDENT IN A WASTE SUPERCOMPACTOR

A hypothetical nuclear criticality accident in a waste supercompactor is examined. The material being compressed in the compactor is a homog eneous mixture of beryllium and Pu-239. The point-kinetics equations w ith simple thermal-hydraulic( feedback are used to model the transient behavior of the system. A lumped-parameter energy balance is used to determine the bulk temperature of the system. A computer code has been developed to solve the model equations. The computer code calculates the fission power history, fission yield, bulk temperature of the syst em, and several other thermal-hydraulic parameters of interest. Calcul ations have been performed for the waste supercompactor for various ma terial misleading configurations. The peak power for the various accid ent scenarios varies from 1.04 x 10(17) to 4.85 x 10(20) fissions per second (fps). The total yield varies from 8.21 x 10(17) to 7.73 x 10(1 8) fissions, and the bulk temperature of the system varies from 412 to >912 K.