METHOD OF TREATING RADIOACTIVE SOLUTION Russian patent published in 2014 - IPC G21F9/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of treating a radioactive solution containing cobalt radionuclides along with an organic complexing agent and caesium radionuclides. The method involves adding to the initial radioactive solution an oxidising reagent while providing a given pH of the solution and an iron (II) containing reducing agent to reduce cobalt (III) to cobalt (II) and for decomplexation of the latter, adding a precipitation agent to transfer cobalt and caesium radionuclides into a precipitate and separation thereof from the mother solution containing the organic complexing agent and a residual amount of cobalt and caesium radionuclides. The oxidising reagent used is nitric acid; the iron (II) containing reducing agent is added in amount of 0.5-2.0 g/l Fe (II) at pH 3.0-3.5 with decomplexation of cobalt by iron (III) compounds formed in the solution; the obtained solution is held for 2-6 hours; the precipitation agent used is sodium sulphide Na₂S in an amount which is stoichiometrically required to form, at pH 4-6, a basic collective precipitate of iron sulphide FeS, which contains cobalt and caesium radionuclides, wherein the mother solution goes through a post-treatment cycle.

EFFECT: method reduces the amount of reagents used and a minimal weight, with respect to the solution being treated, of the radioactive precipitate to be disposed of, as well as high degree of purification of the solution from cobalt and caesium radionuclides.

8 cl, 4 ex