Tritium diffusion in nonmetallic solids of interest for fusion reactors. Final report

Tritium diffusion measurements have been conducted in Al/sub 2/O/sub 3/, BeO, Y/sub 2/O/sub 3/, SiC, B/sub 4/C, Si/sub 3/N/sub 4/ and pyrolytic carbon as a basis for evaluating these materials as potential tritium barriers in fusion reactors. Deuterium solubility measurements were conducted with Al/sub 2/O/sub 3/, SiC and pyrolytic carbon to establish the pressure and temperature dependence of solubility and to identify solubility ranges. Hydrogen permeability measurements on commercially available Al/sub 2/O/sub 3/ and SiC materials were used as a check on calculated permeabilities and to provide data on hydrogen permeation rates in polycrystalline materials. The diffusion, solubility and permeation results are presented and discussed in terms of fusion reactor applications.