Behavior of Uranium in the Partitioning Process of PUREX Reprocessing

Abstract

The impact of the removal of the U scrubbing column from a standard Pu partitioning process on the product Pu solution was estimated and the amount of U(IV) mixed into the product Pu solution by changing the organic/aqueous phase flow rate or U(IV) feed rate as a reductant was also evaluated in a standard flow sheet. By removing the U scrubbing column, a Pu solution containing uranium of 76.9 wt% is obtained, compared with that of 8.7 wt% achieved in the standard process. The surplus U(IV) as a reductant can be mixed into the Pu solution intentionally by increasing the flow rate of the Pu scrubbing solution or by decreasing the flow rate of the U solvent. A Pu solution containing 1.0–80.0 wt% uranium is obtained by controlling the flow rate of the Pu scrubbing solution and the U(IV) feed rate supplied as a reductant. The behavior of U(IV) in the partitioning process can be explained by the axial profiles of the extraction factor (Λ) for U(IV). It is suggested that pure Pu recovery can be prevented by these methods and the Pu product will contain a significant ratio of U.