Study of isotope exchange reactions on ceramic breeder materials deposited with noble metal

Lithium orthosilicate is one of the candidate materials of the tritium-breeding blanket of the D–T fusion reactors. Tritium is released via the exchange reaction with sweep gases containing hydrogen. It is expected that the isotope exchange reaction is promoted by adding noble metals that possess catalytic functions. Thus, palladium was deposited in a sample of lithium orthosilicate, and the effect of catalyst on the rate of isotope exchange reaction on the sample surface was examined. It was found that the isotope exchange reaction proceeds faster even at lower temperatures over the breeder materials with a catalytic additive and its activation energy can be considerably lowered. This result suggests that the isotope exchange reaction can be promoted by the deposition of catalytic metals.