Study on the technology of U-Pu Co-stripping process for reprocessing spent fuel of fast reactor

Abstract

To develop an aqueous reprocessing process for spent fuel of fast reactor, a counter current experiment (U-Pu co-stripping) based on a simplified PUREX process was carried out with 30%TBP/Kerosene solution containing U, Pu and HNO₃. The experiment was done in a 16-stage miniature centrifugal contactor. The stripping percentage of U was 99.99%, Pu 99.94%. U stripping mainly took place in X1-feeding stage (11.00 mol/L HNO₃ feeding stage) to the 16th one, while Pu stripping mainly took place in the first stage to the X1-feeding stage. And a simple method was presented to calculate c_{U/X1−feeding stage, Org} when the X1-feeding stage number is more than 7 and the stripping percentage of U from the X1-feeding stage is more than 99.9% through the rear stages' stripping. The calculation results by this method were validated by Computer Simulation when only changing U concentrations in feed solution from 40.0 g/L to 90.0 g/L or only changing the X1-feeding stage from the 7th stage to the 11th one. Finally the optimized technology was given.