2021 年 35 巻 2 号 p. 337-345
After the accident at the Fukushima nuclear power plant, filtered containment venting systems (FCVSs) have garnered increasing attention as an effective facility for nuclear accident management. FCVSs with a wet-type scrubber, a droplet separator, and several other stages for fine aerosol filtration are typical used of many countries. Most of these FCVSs comprise a self-priming venturi scrubber nozzle for air injection. An optimized design of the VS (in terms of the throat length, throat size, nozzle diameter, etc.,) may significantly improve the filtration efficiency of the nozzle and wet-scrubber filter. Furthermore, adding a baffle plate on top of the VS also can improve the efficiency of the wet-scrubber filter. In this study, to understand the effects of the baffle plate on the efficiency of the wet-scrubber filter, two VS nozzle configurations were used. The difference between these two configurations is that one of them involved a baffle plate installed above the outlet. The decontamination factors of the wet scrubbers using these two nozzle configurations were measured and compared. The two-phase flow pattern in the pool was observed using a high-speed camera. It is discovered that the baffle plate contributed to increase the efficiency of the wet-pool scrubber. Moreover, the aerated surface exhibits better stabilization when the baffle plate is used.
