Compatibility of SiC/SiCfibre composites with lithium silicate and lithium titanate in fusion relevant conditions

The compatibility of SiC/SiCfibre composite with Li4SiO4 or Li2TiO3 solid pebbles beds has been investigated. The experimental parameters were chosen to fall within the range of fusion relevant conditions, typically 800 deg. C in flowing He containing 1000 ppm H2. Six cells were installed with the aim to evaluate the processes involved and their kinetics by analysing samples before and after 216, and 1000 hours of exposure. Dimensions, weight, density, elastic properties and thermal diffusivity have been measured and no substantial changes detected, apart from the damping constant whose values increased by a factor 5-6 after 1000 hours exposure to lithium titanate. In addition the evolution of the mechanical properties of the composite has been investigated and no changes detected within the experimental error. (authors)