THE BEHAVIOR OF CERAMIC BREEDER MATERIALS WITH RESPECT TO TRITIUM RELEASE AND PELLET PEBBLE MECHANICAL INTEGRITY/

In situ tritium release experiments from several candidate fusion blan ket ceramic breeder materials have been performed in the High Flux Rea ctor (HFR) at Petten over the last few years. The sixth experiment, EX OTIC-6, contained pellets of LiAlO2, Li2ZrO3, Li6Zr2O7 and Li8ZrO6 and pebbles of Li4SiO4 and Li2ZrO3 which were irradiated up to a lithium burnup of 3%. A large number of temperature transients and purge gas c omposition changes were performed. From the temperature transients tri tium residence times have been determined. Some preliminary results we re presented at the 17th Symposium on Fusion Technology (SOFT) held in Rome in 1992. In the present paper results of a further analysis of t he residence times are presented together with some postirradiation ex amination results. The LiAlO2 pellets showed a better mechanical stabi lity than the Li-zirconates pellets. The pebbles remained intact. The tritium residence times determined from the tritium inventories were i n good agreement with those previously determined from temperature tra nsients. The tritium release characteristics of the materials investig ated remain substantially unchanged up to the maximum lithium burnup a chieved in this experiment.