SIMULATING OF DROP ENTRAINMENT IN THE JET-VORTEX CONDENSER OF THE VVER-440 CONFINEMENT SYSTEM

The article presents the results of simulating the jet-vortex condenser operation. The jet-vortex condenser used as a part of the confinement system is designed to ensure the confinement integrity of an NPP with VVER-440 unit during LOCA accidents. To simulate the jet-vortex condenser operation it is important to keep a sufficient amount of water after a pressure peak was reached in the jet-vortex condenser hydraulic lock. The loss of water due to drop entrainment with steam-air mixture flow into the atmosphere stops when the velocity of drop sedimentation becomes higher than the velocity of drop entrainment with the mixture flow. The jet-vortex condenser model integrated into the KUPOL-M code was validated against the experimental data obtained on the VNIIAES test facility. To take into account drop entrainment with steam-air mixture flow the procedure of moisture separation and drop entrainment was used. A good agreement between calculated and experimental results was obtained when comparing the initial and final water levels in the hydraulic lock. The research results confirmed validity of the model of drop entrainment with steam-air mixture flow during the operation of the jet-vortex condenser and the preservation of water into the hydraulic lock during the accident.