Tritium Permeation through Ce-ODS Steel

Tritium permeability through FeCrAl-oxide-dispersion-strengthened (ODS) ferritic steel containing Ce oxides (Ce-ODS steel) was measured at temperatures ranging from 373 to 623 K. Some of the Ce-ODS steel specimens were oxidized by means of an autoclave treatment at 563 K for 30 days to examine the effect of the surface oxidized layer on the tritium permeability. The tritium permeability obtained for nonoxidized specimen was consistent with that for other common ferritic steels and FeCrAl ferritic steel. For the oxidized specimen, the surface oxide layer suppressed the apparent tritium permeability. The permeability for the oxidized specimen also depended on the atmosphere of the downstream in the permeation experiment: An atmosphere containing water vapor yielded lower tritium permeability compared with a reductive one.