Study on tritium removal performance by gas separation membrane with reflux flow for tritium removal system of fusion reactor

Iwai, Yasunori; Yamanishi, Toshihiko; Hayashi, Takumi; Nishi, Masataka

Addition of gas separation membrane process into usual tritium removal process from atmosphere in a room is attractive for fusion plants where a large amount of atmosphere should be processed. Therefore, the gas separation membrane has been studied. New concept of membrane separation with reflux flow is proposed in the present. Driving force of membrane separation is the difference of partial pressure through membrane. Hence, reflux of a part of gases at permeated side to feed side enhances driving force. Essential points of present discussion are as follows: (1) Reflux has plus effect of driving force enhancement and minus effect of feed flow increase, hence, there is the optimum. (2) Permeated-side pressure effects enhancement of tritium recovery strongly. (3) Effect of reflux becomes striking as the target species have higher permeability coefficient, therefore, it is favorable for tritium recovery because those of hydrogen gas and water vapor are much higher among atmosphere elements. In addition, application of reflux flow will realize scale reduction of expensive membrane module.