Release of cesium from zirconia inert matrix

The release upon annealing or irradiation at high temperature of fission pr oducts (Cs) from zirconia, a candidate for inert matrix, is studied by Ruth erford backscattering experiments. The work is focused on the understanding of the influence of various parameters (mainly the atomic concentration of foreign species and the damage created by an external irradiation) on the diffusion and release of Cs. The results reveal that the Ca mobility is str ongly enhanced when the impurity concentration exceeds a threshold of the o rder of a few atomic per cent. Irradiation with medium-energy heavy ions is shown to cause a further increase of the Ca mobility. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.