Beryllium Melt Motion and Splashing from First Wall in ITER: OpenFOAM CFD Modeling *

Beryllium (Be) material possesses low density, high strength, and high thermal conductivity. Therefore, it is planned to be utilized as a first wall in ITER. However, the Be first wall panels can undergo melting and melt splashing during the transient events of high magnitude that can lead to the surface erosion. Be droplets which ejected from the melt surface can affect drastically the efficiency of ITER fusion reactor. Therefore, it is important to analyze the physics mechanisms governing the Be melt splashing under the relevant ITER conditions. The OpenFOAM CFD model was used to investigate the effects of Be vapor on the melt motion and splashing. The influence of vapor pressure, mass density and velocity changing with the temperature at the surface on the Be melt motion and droplet ejection is studied. The results provide an insight into the development of melt structures and waves at the vapor-melt interface and physical mechanisms of melt entrainment into the motion within a thin boundary layer.