Real-scale numerical simulation of gas entrainment phenomena in fast reactor

Ito, Kei; Kunugi, Tomoaki*; Ohshima, Hiroyuki; Kawamura, Takumi*

To evaluate gas entrainment (GE) phenomena in a large-scale sodium-cooled fast reactor, the authors are developing a high-precision numerical simulation algorithm for gas-liquid two-phase flows based on a volume-of-fluid methodology. In this study, the simulation algorithm is applied to a real-scale GE test to check the applicability of the algorithm to the GE phenomena in the fast reactor. As a result, transient behaviors of the vortical flows around the pipes and the accompanied GE phenomena are simulated well. In particular, the origin of the flow which induces the GE phenomena is showed clearly. Finally, from the investigation of a lot of GE phenomena observed in the simulation result, it is verified that the GE phenomena by relatively strong vortical flows are important in terms of the GE suppression in the fast reactor.