CURRENT MATERIAL AND DESIGN STUDIES FOR THE UTILIZATION OF LI2ZRO3 INTHE BIT BLANKET CONCEPT

The DEMO-relevant, helium-cooled, BIT blanket concept jointly develope d by CEA and ENEA has been originally designed on the basis of LiAlO2 properties data. Owing to its excellent tritium release behaviour Li2Z rO3 is being evaluated too. Thus, development of the Li2ZrO3 ceramic i s in progress at CEA and conceptual work is partly devoted to the adap tation of the design using Li2ZrO3 characteristics. The material devel opment work is focused on improving the thermomechanical behaviour of Li2ZrO3 with the aim to ensure ceramic pellet integrity during blanket operation. Such an improvement should be achieved without significant change of the tritium release characteristics. Among means being atte mpted is microstructural tailoring, i.e. density adjustment. Mechanica l tests, thermal cycling tests and tritium release annealing tests all ow to evidence any changes. A feasibility study of large scale product ion of BIT-type Li2ZrO3 pellets was undertaken with industry. In paral lel, conceptual work is concentrated on redesigning the BIT concept wi th Li2ZrO3 properties data, on calculation of tritium breeding ratio, and on evaluation of the maximum lithium burnup in the breeder.