Reduction-oxidation of actinides extraction process (ROANEX) for used nuclear fuel recycling

A method for processing used nuclear fuel in a single purification cycle, the method comprising the steps of:

• a. diluting the used nuclear fuel into a nitric acid solution (HNO3) to form a first solution, the used nuclear fuel containing a plurality of actinides and a plurality of fission products, the plurality of actinides including U(VI), Am(III), Pu(IV,V,VI), Np (IV, V, VI), and Cm (III), the plurality of fission products including at least Cs, Sr and Tc (VII), the concentration of the nitric acid in the first solution being approximately equivalent to a first predetermined molarity;
• b. separating fission products Cs and Sr from the first solution;
• c. diluting said first solution to form a second solution, the second solution having a concentration of nitric acid approximately equivalent to a second predetermined molarity;
• d. removing Tc(VII) from the second solution to form a third solution;
• e. adjusting said third solution to form a fourth solution, the fourth solution having a concentration of nitric acid approximately equivalent to a third predetermined molarity;
• f. adding a reductant to the fourth solution to form a reduction phase solution, the reduction phase solution including U(III), Am(III), Pu(III), Np(IV), and Cm(III);
• g. adding an oxidant to the reduction phase solution to form an oxidation phase solution, the oxidation phase solution including U(VI), Am(V or VI), Pu(IV), Np (IV), and Cm (III);
• h. adding an organic extractant solution to the oxidation phase solution to form an organic phase solution and a nitrate solution, the nitrate solution including Am(V or VI) and Cm(III);
• i. stripping U(VI), Pu(IV), and Np(IV) from the organic phase solution to form an aqueous phase solution;
• j. adding a predetermined acid to the aqueous phase solution to form a precipitate;
• k. heating the precipitate to form a first mixed oxide fuel (MOX), the first MOX including UO2, PuO2, and NpO2.