DEVELOPMENT OF A COMPUTATIONAL MODEL TO DETERMINE PERFORMANCE OF A SELF-PRIMING VENTURI SCRUBBER FOR THORIUM REACTOR

摘要

Following the post-Fukushima measures on reactor safety, the Filtered Containment Venting System (FCVS) is a mandatory to all Nuclear Power Plants worldwide. In order to ensure the capture and retention of the released radioactive fission products, the FCVS employs a manifold of self-priming venturi scrubbers submerged in a pool of liquid. The performance of the venturi scrubber significantly affects the overall performance of the system. To arrive at an efficient venturi design, a computational model is proposed to evaluate the pressure drop and the capture efficiency of the scrubber. The gas phase is modeled using an Eulerian approach while the dispersed droplets and the aerosol particulates are tracked through a Lagrangian approach. The model includes atomization of liquid jet, breakup of droplets and interaction of gas and liquid droplets. The collision efficiency of the scrubber is based on single droplet capture efficiency with the assumption that capture occurs only if the aerosol particulates and the droplets exist in the same computational cell. The numerical results show a qualitative match with earlier experimental data for pressure drop and collection efficiency.