Lithium metasilicate pellets with tailored grain size and open porosity have been produced with densities from 60% TD to more than 95% TD. These characteristics are obtained by choosing appropriate preparation conditions among the five fabrication routes discussed in this paper. An investigation of the influence of deviations from stoichiometry shows that density, grain size, porosity and recrystallization are affected by the type of the secondary phase but not by its quantity. The effect of the fabrication conditions on specific surface area and moisture content is also mentioned.Thermal stability tests were performed between 500 °C and 925 °C. Dimensional and structural changes were not detected up to 700 °C. Above 750 °C, changes were observed in pellet weight, dimension and density as well as in grain size and porosity. These changes depend on the type of the secondary phase, the fabrication conditions, the pellet structure and texture. Minor changes in stoichiometry were also established.
Simulations of density profiles, pellet fuelling and density control in ITER