The study of hydrogen diffusion parameters in austenitic steels EP-838, Cr12Mn20W, 316 SS, 12Cr18Ni10Ti was carried out. Temperature dependences of permeability, diffusion coefficients and hydrogen dissolution were determined and their variation with the phase and structure composition of the steel were analyzed. It is shown that change of alloy composition, thermal treatment in hydrogen and modification of surface by nitriding, oxidizing and by irradiation with H+ and N+ ions can lead to a decrease in hydrogen permeability and thus reduce hydrogen isotope losses through the thermonuclear reactor first wall.