Abstract: The method of processing alkaline solutions containing radioactive iodine consists in dissolving irradiated fuels in a nitric acid solution. The vapors constituted essentially by nitrogen oxides, iodine and water formed during dissolution are passed into a condenser and then into a first absorption column in which the recombined nitric acid is formed. The recombined acid is returned to the dissolver while the gases discharged from the first absorption column are passed into a second absorption column in counterflow to an alkaline solution which is loaded with iodine and with nitrous ions. The alkaline solution discharged from the second absorption column is passed into a reaction vessel containing a mixture of nitric acid and sulphamic acid which destroys the nitrous products and releases the iodine.

Abstract: The method for processing a mixture of air and rare gases consisting especially of xenon and krypton which are at least partially radioactive and especially for processing gaseous effluents arising from the reprocessing of irradiated fuels comprises a step involving concentration of the rare gases in solution in liquid argon by cryogenic distillation of the light gases and mainly nitrogen from the liquefied mixture.

Abstract: After dissolving irradiated nuclear fuel in a nitric acid medium, the vapor produced by this dissolution and consisting of water, nitrogen oxides and iodine is passed into a condenser, then into a column for the absorption of the nitrous vapor in which is formed recombined nitric acid containing iodine and nitrous ions, the iodine contained in the recombined acid being then separated-out. The nitrous ions present in the recombined acid have a favorable influence on the important first stage of that separation.