Process and installation for the decontamination of radioactive nitric effluents containing strontium and sodium

Process for the decontamination of a radioactive nitric aqueous effluent containing strontium and sodium, wherein the effluent has a nitric acidity of 0.5 to 2N, a strontium concentration up to 2 .mu.g/l and a sodium concentration of 0.01 to 0.2 mol/l, comprising the steps of:

• a) contacting the aqueous effluent with an organic phase incorporating a crown ether and a diluent, chosen so as to obtain an extraction selectivity of strontium compared with sodium such that the D.sub.Sr /D.sub.Na ratio, in which D.sub.Sr and D.sub.Na respectively represent the strontium and sodium distribution coefficients, is equal to or above 100 and D.sub.Sr is at least equal to 1,
• b) reextracting the strontium present in the organic phase in an aqueous solution, and
• c) fixing the strontium reextracted in said aqueous solution on a cation exchange resin.