Progress in Tokamak exhaust processing technology

Tokamak exhaust processing system is an important part of deuterium-tritium fuel cycle system in fusion devices. Its main function is to recover unspent deuterium-tritium fuel from the exhaust gas. Moreover, tritiated gaseous wastes from various other sources are also accepted and decontaminated by the Tokamak exhaust processing system, including the deuterium or helium stream during wall conditioning (glow discharge cleaning), the fluids from the retrieval of tritium from plasma facing components and co-deposits, the tritiated gases yielded during system maintenance, as well as the gases from analytic and auxiliary systems. In this review, the progress in Tokamak exhaust processing technology is summarized, including the compositions of Tokamak exhaust gas and the main methods of Tokamak exhaust processing. The principles and progress of key subsystems technologies in Tokamak exhaust processing system are introduced, such as palladium membrane permeation, palladium membrane reaction and catalytic reaction-palladium membrane permeation, electrolysis reaction, decomposition and oxidization-decomposition reaction. After that the key technologies are analyzed and evaluated. Finally, the main problems and the gap between domestic and foreign development in this field are presented, and necessary research work in the future is proposed.