This paper examines the main features of the gas purification process from tritiated water vapor at any relative humidity using water phase isotope exchange. The experimentally evaluated overall mass transfer coefficient (KOG) for structured CY black packing manufactured by SULZER Chemtech (Switzerland) was used as the main performance parameter of the method. The obtained KOG dependencies on various process parameters (temperature, water and gas flows, and their ratio) demonstrate that column operation in adiabatic mode is preferable for the detritiation of gas at any relative humidity. Under comparable conditions, KOG does not depend on the column diameter in the investigated range. A comparison of the main characteristics of the developed technology with those of the technology based on water vapor adsorption on molecular sieves shows clear advantages in terms of energy, operating cost, and detritiation degree with the same amount of tritiated water produced as a radioactive waste.