The moisture concentrations at inlet and outlet of the auxiliary molecular sieve bed and the operating temperatures at regeneration inlet and regeneration outlet of the molecular sieve bed were monitored, with the experimental results shown in Fig. 3. As shown in Fig. 3, the moisture concentration at outlet of the auxiliary molecular sieve bed kept being less than 3 ppm, while that of inlet of the auxiliary molecular sieve bed firstly increased to more than 1000 ppm and eventually decreased to be less than 400 ppm. It should be noted that the final inlet water concentration of the auxiliary molecular sieve bed being approximately 400 ppm is considered not representing the regeneration outlet water concentration of the molecular sieve bed, which was attributed to the liquid water retained in the dead volume of the piping. By directly measuring the water concentration of regeneration outlet of the molecular sieve bed, the water concentration was less than 37 ppm. It was obvious that a large quantity of water was adsorbed by the auxiliary molecular sieve bed at this experimental stage, while the water condensed at the water separator of helium purification regeneration system was only 280 g. The tritium-containing waste water was sampled by isolating the water separator from regeneration system piping and alternately opening valve of V10 and V11. The specific activity of the tritium-containing waste water collected at this experimental stage was measured to be 6.1 × 109 Bq/L.