Method of treatment of a mixture of air and at least partially radioactive rare gases

A method for treating radioactive effluent gases obtained from reprocessing of irradiated nuclear fuels containing xenon, and krypton which is radioactive in air by treating a mixture thereof also containing oxygen, nitrogen oxides, gaseous carbon dioxide, water vapor, argon and hydrocarbons comprising

• i. removing nitrogen oxides, gaseous carbon dioxide, water vapor and hydrocarbons contained in said effluent gas mixture therefrom, thereafter
• ii. liquifying the oxygen in said effluent gas mixture and distilling off gaseous nitrogen oxides a portion of the oxygen, and argon contained therein in a cyrogenic distillation column thereby forming a concentrated liquified mixture in the lower portion thereof, said concentrated liquified mixture also containing ozone formed from oxygen in the radioactive medium,
• withdrawing a fraction of said ozone-containing liquified mixture from said distillation column and dissociating said ozone in said liquified mixture and then returning said liquified mixture to said distillation column, and removing a liquified mixture of oxygen containing xenon and krypton from the lower portion of said distillation column, then
• iii. adding hydrogen to said oxygen containing xenon and krypton and catalytically combining said oxygen with said hydrogen to form water and removing said water, to form an admixture of xenon and krypton, and
• iv. cryogenically distilling said admixture of xenon and krypton to distill the krypton as a gas from liquid xenon and recovering said xenon.