Effects of breach size and dust density on activated dust mobilization in ITER during a loss-of-vacuum event

Activated dust mobilization in the International Thermonuclear Experimental Reactor (ITER) during a loss-of-vacuum-accident event (LOVA) was analyzed numerically by three-dimensional computations using a newly developed analysis code. A physical model on the motion of dust was proposed to resolve the dust transport conveyed by the fluid. Air ingress behavior through a breach at the LOVA was also calculated. In the present study, effects of breach size and dust density on activated dust mobilization in ITER during the LOVA were clarified quantitatively. From the present results, it was found that the saturation time in a vacuum vessel (VV) of ITER after the LOVA occurred depends on the breach size and then the mobilized dust fraction of beryllium, carbon, stainless steel, copper, and tungsten, which are VV component materials, were 1.7, 0.7, 0.5, 0.4 and 0.1%, respectively.