Research works on contamination transfers through cracked concrete walls

This study takes place within the framework of nuclear facilities containment assessment. The aims are to determine gaseous flow, two-phase flow and aerosol deposition models through a crack network by using the most realistic and representative crack network characteristics. For this, the crack network is considered as two infinite parallel plates. First of all, airflow experiments are performed on three concrete walls (128 cm in width, 75 cm in height and 10 cm in thickness), cracked by shear stresses. The results enable determining aeraulic crack network characteristics, thanks to the Poiseuille model in laminar compressible flow, and elaborating an experimental friction factor correlation for the transition flow, validated up to a Reynolds number of 250. Next, aerosol deposition experiments were performed with one of the previous concrete walls in order to determine a global aerosol deposition model in a crack network. The first experiments with an aerosol diameter of 60 nm showed that the aeraulic crack network characteristics are suitable for the aerosol physics. Therefore, geometrical crack network characteristics were determined by using several types of experiment and enable – thanks to aerosol deposition experiments – constituting and validating a global model of aerosol deposition in a crack network.