During neutron irradiation of ceramic breeders, not only does the transmutation of Li to T and He take place but other isotopes are formed as well, and the impurities contained will all contribute to the induc­tion of radioactivity from exposure to the neutron irradiation environment. This enables assessment of the feasibility of recycling ceramic breeder material from blanket components having reached EOL con­ditions. Recycling options for ceramic breeder material not only avoid large waste volumes requiring long-term storage but also contribute to resource effi­ciency of valuable constituents such as lithium. From a ceramic breeder perspective, Li2O, Li2TiO3, and Li4SiO4 are more attractive than Li2ZrO3 due to their long-term activation characteristics.

Knitter et a/.187 assessed contact dose rates of different Li4SiO4 materials for high radiation levels expected from a fusion power reactor for 1 FPY. As an example, Figure 64 displays the contact dose rate versus time after shutdown for pure Li4SiO4, which specifically results from the production of 28Al, 24Na, 7Be, and 26Al. Due to the activity of 7Be, the recycling limit for remote handling (10mSvh~) and the
hands-on limit (10muSvh-1) are reached after <1 and <4 years, respectively. The activation of as manufactured Li4SiO4 appears to be strongly influenced by impurities, of which Co and Pt appear to be the most important.187 Knitter et a/. also simulated remelting of lithium depleted Li4SiO4

experimentally.188

Pebble manufacturing routes by wet processes require different considerations for reprocessing.196 In the powder preparation stage the powders need to be produced from pre-existing pebbles by dissolution and precipitation steps; see, for example, Tsuchiya eta/.184