Mobilization Characteristics of Dust Conveyed by Buoyancy Flows during Loss-of-Vacuum Accident

Dust mobilization in a vacuum vessel (VV) of a fusion reactor during a loss-of-vacuum accident (LOVA) was studied numerically and experimentally from a viewpoint of the fusion safety research. After the LOVA occurred, air flows from the outside of the VV through a breach into the inside and the activated dust is blown up from the walls inside the VV, and then it can be considered that the dust is conveyed due to a buoyancy flow to the outside of the VV through the breach. The velocity, pressure and temperature distributions were obtained by the present numerical analyses and the dust mobilization behavior was predicted quantitatively. In addition, the dust transport characteristics from the inside of the VV through the breach to the outside due to the buoyancy effect was clarified by the visualization experiments.