Study of Thermal-Hydraulic Characteristics During Decay Heat Removal in a Pool-Type Fast Breeder Reactor

The thermal-hydraulic characteristics of a pooltype fast breeder reactor during decay heat removal are studied experimentally with a one-eighth-scaled threedimensional reactor model using water as the working fluid. The model is designed to simulate reactor operations from full power to scram transient and decay heat removal conditions as well as two types of decay heat removal systems, a direct reactor auxiliary cooling system (DRACS) and a primary reactor auxiliary cooling system (PRACS). The transient thermal-hydraulic performance of the DRACS is compared with that of the PRACS for the water test results. The results are used to evaluate the accuracy of the multidimensional analysis codes AQUA and THER VIS. The analytical results are generally in good agreement with the measurements.