Tritium release behavior through structural material in the presence of molten lithium-lead alloy (Li17Pb83) was studied in TREXMAN program. Tritium permeation ratio to the secondary carrier gas line depends strongly upon H2 pressure in He sweep gas of the primary and the secondary carrier gas lines. It increased with increasing H2 pressure below 104 Pa and above the value it became constant. An analytical model was applied to the experimental data on the tritium release to obtain the mass transfer coefficient.