Numerical simulation of wall condensation and direct contact condensation in containment suppression pool of PWR

Highlights: • Evaluation of suppression pool system in PWR containment. • Verification of wall condensation and direct contact condensation based on Mixture model. • Verification of POOLEX STB-28. - Abstract: This work aims to evaluate the pressure-control capacity of a passive suppression pool system applied in PWR containment. The numerical models construct for wall condensation and direct contact condensation based on Mixture model are firstly examined with the experimental data of POOLEX STB-28. The simulation under Mixture model show good accordance with experimental result. Under a double-end rupture of the main pipe of the first loop, the pressure and temperature evolutions under the effect of suppression pool are analyzed. During the operation of the suppression pool, the existence of non-condensable gas affects the efficiency of wall and direct contact condensation. The absolute pressure in the free area of the containment rises to 3.7 bar in 50 s then becomes stable. During a simulation period of 300 s, the gas temperature rises to the saturation temperature, while the variation of water temperature is less than 5 K.