An in-pile demonstrated platform for the evaluation of tritium extraction technologies in China Mianyang Research Reactor

The preliminary design of the tritium extraction system for CFETR breeding blanket has been completed. In the design, two molecular sieve packed columns are connected in series to achieve both hydrogen-helium separation and tritium enrichment. The first column primarily focuses on hydrogen-helium separation and volume reduction, while the second column, which is thinner and longer than the first, is mainly used for tritium enrichment. To achieve tritium-helium separation and tritium storage simultaneously, a U-shaped tritium storage bed is utilized. To verify the feasibility of these tritium extraction technologies, an in-pile tritium release and recovery platform was constructed in China Mianyang Research Reactor (CMRR). This paper provides a detailed description of the in-reactor irradiation device and the design and composition of tritium extraction system. Moreover, an in-situ experiment was conducted in early 2022 to produce and recover tritium with a total activity level of approximately one hundred curies. The experiment obtained various parameters, including tritium release form and ratio of Li4SiO4 with high 6Li abundance, tritium extraction rate, tritium recovery rate of the whole system and tritium penetration in 316 L stainless steel. These results allow for a preliminary evaluation of the feasibility of the designed tritium extraction technologies.