Coupled thermal-hydraulic/aerosol transport analysis capability for severe accidents

Fission product transport and thermal-hydraulic phenomena, occurring during the in-vessel phase of postulated accident progression, affect each other directly and significantly. It is important to couple the calculation of these processes to obtain accurate estimates of the magnitude and the timing of the release, of initial and revolatilized fission products from the primary system of a PWR, or the vessel of a BWR. The Electric Power Research Institute research efforts to obtain a functional and sophisticated coupled thermal-hydraulic/aerosol transport analysis capability are described. These are based on coupling the codes CORMLT, PSAAC (Primary System Accident Analysis Code) and RAFT (Reactor Aerosol Formation and Transport), which have been under development since 1982. Summary descriptions of these codes are also provided. (author)