Investigation of WWER-type and PWR-type model fuel assemblies quenching during loss-of-coolant accident

Abstract

The results of reflooding investigations of WWER-type and PWR-type model fuel assemblies (FA) carried out at largescale facilities (RBHT, SVD, PARAMETER) under Design Basis Accident (DBA) and Beyond Design Accident (BDA) conditions are presented. The regime parameters ranges are: the initial fuel rod temperature -T clad = 460÷1600 о С , water mass rate -ρw = 47÷160 kg/(m 2 •s), FA inlet subcooling -∆T sub = 11 -118 o C, pressure -p=0,14÷0,42 MPa and the linear heat flux density simulating decay heat -q l = 0÷2,3 kW/m. The generalizing correlation on the quench front velocity of model FA's describing the experimental data with 30% error is proposed. It allows to predict the latency of model fuel assemblies reflooding of various design and to evaluate the time of WWER and PWR reflooding.