Lithium ceramic of blankets intend for Russian fusion reactors and an influence of the ceramic properties on parameters of reactor tritium systems

Russian Controlled Fusion Program involves development of a DEMO design and participation in ITER Project. A solid breeder blanket in DEMO contains a ceramic orthosilicate lithium breeder and a beryllium multiplier. Test Modules of the blanket are developed in a frame of ITER activities. Experimental models of tritium breeding zones (TBZ) for the Modules, materials and technology fabrication of the TBZ, tritium reactor systems to control and treat of gases released from lithium ceramic being developed. Two models of tritium breeding and neutron multiplying elements of the TBZ were designed, manufactured and have been tested already in IVV-2M nuclear reactor. The first model consists of lithium orthosilicate ceramic sphere pebbles (1-1.5 mm diameter) and beryllium sphere (0.1 and 1.0 mm diameter). Ceramic cylindrical pellets (11 mm diameter and 10 mm height) and porous beryllium (20% porosity) are in the second model. Some properties and microstructure of the ceramic elements are performed. Initial results of some changes of ceramic structure and in-pile experimental ratio of hydrogen and oxygen form of tritium release in helium/neon purge gas are presented. These results and outcome of irradiated LiAlO2, Li4SiO4 and Li2SiO3 ceramics in a water-graphite nuclear reactor are considered to be a DATE BASE for development of the Test Modules and the DEMO blanket and influence of the kinetic tritium release parameters on DEMO tritium systems are discussed. (author)