Fabrication of Li2TiO3 pebbles by the extrusion–spheronisation–sintering process

Li2TiO3 pebbles are a ceramic breeder material option for the helium cooled pebble bed (HCPB) blanket being developed in the EU. The extrusion–spheronisation–sintering process was selected in order to produce Li2TiO3 pebbles fulfilling the HCPB blanket requirements, and is developed with an industrial collaboration. Adjustments of the fabrication process parameters allows the variation of the pebbles characteristics which, in turn, determine the behaviour of the pebbles and pebble beds. The feasibility of the fabrication by pre-industrial means is demonstrated at the 10 kg scale which is sufficient to cover the present needs for the tests. The advantage of this fabrication process to cover a wide range of characteristics is shown and the influence on Li2TiO3 pebble beds relevant properties, i.e., long-time annealing behaviour, thermal–mechanical behaviour, and tritium release performance is recalled. The overall results indicate both excellent prospects for the fabrication of Li2TiO3 pebbles and the attractiveness of their properties.