Poly (ionic liquid)s for removal of radioactive antimony during nuclear reactor decontamination

Dilute Chemical Decontamination (DCD) is among the most common processes used for the decontamination of nuclear reactors. Indian PHWRs use the NAC process, which involves DCD with formulation containing NTA, Citric acid and Ascorbic acid. The metal ions brought into the solution by the dissolution of oxides deposited on the coolant surfaces by the DCD formulation are removed by the ion exchange resin beds. It was seen during the decontamination campaigns that the removal of antimony was not very effective leading to reduced decontamination factors. One of the factors contributing to this is the ineffective binding of the antimony species by the regular ion exchange resins used during the decontaminations processes. The antimony removal properties in presence of NAC formulation and excess ferrous ions, as seen during typical decontamination of PHWRs, is also explained