Key words: supercritical fluid extraction, liquid and/or supercritical carbon dioxide, spent nuclear fuel reprocessing, uranium, fission products, complexation, tributyl phosphate, aqueous ferric nitrate solution
The behavior of uranium and simulators of fission products during the reprocessing of a model spent nuclear fuel in subacidic ferric nitrate solution using supercritical carbon dioxide containing tributyl phosphate (TBP) is studied. A quantitative isolation of uranium from the ferric nitrate solution simultaneously with its separation from the present fission products can be reached in these conditions. Isolation of uranium from the TBP phase was performed by its back extraction by water hydrogen peroxide solution simultaneously with preci pitation in the form of uranium peroxide. A high efficiency of uranium purification from all fission products is achieved, which allows one to reuse uranium in a nuclear fuel cycle.