Temperature-Dependent Ordinary and Thermal Diffusion of Hydrogen Isotopes through Thermonuclear Reactor Components

摘要

To permit more accurate calculations of tritium permea¬tion for design purposes, theoretical expressions for quasi-unidirectional ordinary diffusion of hydrogen isotopes through nonisothermal plane, cylindrical shell, and spherical shell barriers are presented. Arrhenium-type dependence of mass diffusivity on temperature and steady-state constant-thermal-conductivity temperature gradients through the barriers are considered.nAnalyses that consider thermal diffusion with both con¬stant and temperature-dependent heat of transport are also presented. Other topics discussed are amounts of dissolved hydrogen, variable-thermal-conductivity temperature profiles, hydrogen isotope trapping by chemical impurities, crystal lattice imperfections, and grain boundaries, and mixing rules for dilute dissolution of hydrogen isotope mixtures in metals.