Experimental research on wash-down of insoluble aerosols with condensate on the vertical wall

During severe accidents, the re-migration behavior of radioactive aerosols deposited on containment wall is worth noting. The wash-down of aerosols with condensation flow is a major mode of migration. In this research, several visualization experiments of aerosol wash-down processes on a vertical wall under condensation environments were conducted. Results indicate that the aerosol particles deposited on the vertical wall are washed down in form of discharge rivulets. Initial condensate discharge volume will be higher because of the accumulation of droplets on the wall and gradually decrease to a steady state. The initial migration mass of aerosols is also the highest with the influence of condensate discharge and aerosol loads, and the migration rate decreases exponentially. Several empirical correlations have been proposed, which can predict the washing time, and changes in aerosol removal efficiency on wall. A sensitivity validation analysis on the predictive ability of the wash-down process was carried out, based on experiments with different walls and data from THAI-AW3.