Evaluation of gas entrainment flow rate by numerical simulation

Ito, Kei*; Odaira, Naoya*; Ito, Daisuke*; Saito, Yasushi*; Matsushita, Kentaro ; Ezure, Toshiki ; Tanaka, Masaaki  

In a sodium-cooled fast reactor, the inflow of entrained gas by a free surface vortex in the reactor vessel into the reactor core may cause reactivity disturbance. Therefore, a method to evaluate the gas entrainment (GE) volume flow rate is required in the design of fast reactors. In this study, as part of the investigation of the mechanism determining the GE volume flow rate, the numerical analysis targeting the free surface vortex in an experimental system in which the upper and lower cylindrical containers are connected by piping was performed, and the GE volume flow rate under various pressure conditions was evaluated. As the result, it was confirmed that the change in GE volume flow rate when the pressure difference between the upper and lower containers was changed was consistent between the experimental and analysis results, and that the GE volume flow rate could be evaluated by numerical analysis.