Numerical analysis of the dust distribution during LOVA

During loss of vacuum accident (LOVA), the dust in the divertor may be resuspended with the air ingression, to threaten the safety of the fusion device. There is the need for further study of the dust distribution characteristics to evaluate the possibility of the risk of dust explosion. The three-dimensional numerical model of ITER is built by computational fluid dynamics (CFD) method, which is validated by comparison with the results calculated by the code MELCOR in Accident Analysis Report (AAR). The migration process of dust composed of beryllium particles during LOVA is reproduced, in which the dust distributions at different heights and moments are investigated, showing that the average volume fraction of dust particles decreases in the early stage and then remains approximatively constant with the height increasing and that the maximum volume fraction of dust particles decreases as a whole with the height increasing. The effects of the dust mass and the crevasse location on the dust distribution have been discussed, which shows that the dust distribution in the space will not change noticeably with the assumed initial dust mass increasing, and also shows that the condition of different crevasses has an impact on the distribution of dust. This research can provide a reference for the safe operation of the ITER device.