Tritium retention in CX-2002U and methods to reduce tritium inventory

Tritium retention in CX-2002U was studied by exposure to high flux of D/T atomized particles. The amount of tritium retained in CX-2002U appeared to be proportional to the half power of total incident fluence below 597 K and to the one third power at 897 K. No saturation was observed up to 1027 atoms/m2 at 297 K. The tritium concentration profile was also measured by means of autoradiography, from which an overall diffusion coefficient of Dt = 3.6 x 1014 m2/s at room temperature was estimated. This value, which was much larger than the reported bulk diffusion coefficient, implies additional diffusion processes such as pore diffusion of tritium atoms or molecules. Tritium removal from the sample by exposure to air and helium plasma after irradiation of D/T atomized particles was studied. Tritium retention was reduced by about one tenth during air plasma exposure and by about a half during helium plasma exposure. (orig.)