AbstractA batch distillation of tritiated water ( ∼ 10 nCi/cm3) has been performed in a packed column of 1.6 cm inner diameter × 100 cm high. Packings were Dixon rings made of SUS. The concentration of tritium was measured at both ends of the column, and then the numbers of theoretical stages and the values of HETP were obtained as a function of the vapor rate within the column. The HETP value for the Dixon rings increased with the increasing vapor rate.