[Recovery and purification of leakage radioactive krypton]

A recovery-purification system for radioactive Kr was constructed by enclosing an 85Kr testing apparatus with an airtight vessel. Experiments were carried out to examine the recovery rate of leakage Kr and the purity of Kr recovered with the system. The concentration of the leakage Kr in the airtight vessel was decreased to a detection limit of 0.3 ppm by the system. The recovery rate corresponded to 99.976%. The concentration of the Kr recovered was over 99.9908%. It shows that almost 100% of the radioactive Kr leaked out into the airtight vessel could be recovered and the He content in the Kr recovered could be reduced to less than 100 ppm.