Analysis of tritium extraction from liquid lithium by permeation window and solid gettering processes

Tritium recovery from liquid lithium at low concentrations is an important problem in the study of liquid metal breeder-blankets in a fusion reactor. In this paper, we focus on the analysis of tritium extraction by permeation window and gettering processes. A time-dependent mass conservation equation for tritium in the liquid lithium and a diffusion equation for tritium transport in the permeation tube were solved simultaneously. The effects of the diffusivity in the permeation tube were discussed. In the gettering process, it is important to characterize the tritium breakthrough curves as a function of the getter material characteristics, operating conditions, equilibrium adsorption data and mass transfer coefficients. The analysis approach utilized in the present paper involves solving the momentum equation of the liquid lithium and the mass conservation equation of the tritium in the packed bed column, coupled with the diffusion equation of the tritium in a single particle. It was found that the tritium breakthrough curve at the near-wall region is different from that at the center region in the getter bed.