METHOD OF PRODUCING COMBINED SOLUTION OF U AND Pu Russian patent published in 2015 - IPC G21F9/06 

FIELD: atomic physics.

SUBSTANCE: present invention relates to a method of producing a combined solution of U and Pu when treating irradiated nuclear fuel of a nuclear power plant. The disclosed method includes preliminary extraction of U, Pu, Np and Tc from a nitric acid solution with 30% tributyl phosphate solution in an aliphatic diluent. Separation of Te and re-extraction of Pu are carried out using a solution of depleted or regenerated uranium in the form of U(IV) from purification from neptunium using a hydrazine nitrate-stabilised solution of U(IV) with high concentration of nitric acid, fed into the first step of the zone for washing the Pu(III) re-extract from U(VI) in a Pu re-extraction unit with a flow rate which provides, in the washed Pu(III) re-extract, a weight ratio U:Pu of up to 6. The method includes simultaneously feeding into the middle of the unit a small stream a weakly acidic solution of U(IV) and at the end of the unit a solution containing 0.1-1.0 mol/l HNO₃ and 0.05-0.5 mol/l N₂H₅NO₃ with flow rates which enable to output Np(IV) and excess U(IV) with a U(VI) extract, followed by oxidation of U(IV) and separation of U(IV) and Np.

EFFECT: combining methods for combined production of Pu and depleted U by using a solution of depleted uranium in the form of U(IV) for re-extraction of plutonium and carrying out the process in strongly acidic conditions for purifying Pu from Np.

4 cl, 1 dwg, 1 ex