Analysis of hydrogen isotopes absorption between liquid lithium and yttrium under dynamic conditions

► The study is to clarify mass transfer of Y hot trap to remove H dissolved in Li flow of IFMIF. ► Low-concentration hydrogen dissolved in fluidized liquid Li is removed by Y. ► Experiment of H transfer in Li and Y and mass transfer model is compared. ► The rate-determining step for H2–Li–Y system is determined from fitting between experiment and calculation. The use of D–Li stripping reaction to generate multiple neutron is expected in the International Fusion Materials Irradiated Facility (IFMIF). Tritium generated by its side reaction needs to be recovered from liquid Li for safety. Y hot trap is expected as an effective purification system to recover tritium from the liquid Li loop. In IFMIF, since liquid Li circulates in a loop, it is important to trace tritium behavior in Y and liquid Li under dynamic conditions. In this study, the authors investigate the effectiveness of tritium recovery from liquid Li under dynamic conditions of Y hot trap. Hydrogen absorption in Li instead of tritium is investigated under dynamically fluidized conditions by stirring liquid Li with an arbitrary rotational rate. The experimental results prove that the hydrogen absorption rate from liquid Li to Y is independent of the rotational rate. This means that the rate-determining step is hydrogen diffusion in Y.