COMPATIBILITY OF STAINLESS-STEELS AND LITHIUM BASED CERAMICS WITH BERYLLIUM

Introduction of beryllium as neutron multiplier in ceramic blankets of thermonuclear fusion reactors may give rise to the following compatibility problems: (a) oxidation of beryllium by ceramics or by water vapour, due to the high stability of beryllium oxide, (b) interaction of beryllium and structural materials. The present report completes previous results and constitutes a synthesis of our work carried out in the compatibility field: (i) interaction beryllium-steels: a mathematical expression giving the thickness of the diffusion zone as a function of exposure duration and temperature for 316L and 1.4914 steels is proposed; (ii) oxidation of beryllium in contact with Li2O is noticeable, this phenomenon being much less pronounced with ternary lithium based ceramics; (iii) the oxidation rate of beryllium in the presence of high water vapour content helium is high above 700-degrees-C.