Method for separatnig uranium from plutonium in parex procedure

Abstract

A process for separating U from Pu in Purex flow includes such steps as cleaning U and Pu, in the HNO3 medium extracting the U and Pu in organic phase TBP solution, adding reducing agent, stirring to reduce Pu(IV) to Pu(III), and back extracting the Pu(III) into water phase HNO3 solution. Said reducing agent is hydroxyurea (HU). Its advantages are high speed and high efficiency.

Description

technical field [0001] The invention belongs to the technical field of nuclear fuel reprocessing, in particular to a method for separating uranium (U) and plutonium (Pu) in the Purex process. Background technique [0002] The Purex process is a process that uses tributyl phosphate (TBP) as an extraction agent to separate and recover uranium and plutonium from reactor spent fuel. In the Purex process, the co-decontaminated U and Pu are co-extracted into the organic phase TBP / alkane diluent. In the TBP / alkane diluent solution, U exists in the combined state of U(VI), and Pu exists in the combined state of Pu(IV). Pu(IV) has a higher oxidation potential than Pu(III) and is easily reduced to Pu(III). Pu(IV) can be reduced to Pu(III) with an appropriate reducing agent, the distribution of Pu(III) in TBP / alkane diluent is very small, therefore, Pu(IV) is stripped after reduction to Pu(III) to the aqueous phase. U(VI) is not reduced, but remains in the...

AI Technical Summary

Problems solved by technology

In order to stabilize U(IV) and Pu(III), it is necessary to add a large amount of hydrazine as a supporting reducing agent, and the use of hydrazine will generate HN in the solution 3 , NH 4 + Substances that are detrimental to the process and the process is complex