Choose and Validate of Technetium Scrubbing Section of Purex Process

The primary technic parameters of technetium scrubbing (TcS) section were discussed. It can be concluded that the optimal technics of TcS section can not only meet the demand of the latter section of Purex process, such as U/Pu separation stage, but also accord the economy of the whole reprocessing plant. The optimization technics were validated through mixer-settler bench scale experiments. The results indicate that both the max decontamination coefficient of Tc and the least loss of U and Pu can be achieved when the concentration of nitric acid of TcSW in TcS section maintains 4-4.5 mol/L. Based on the affirmatory decontamination coefficient of Tc, the optimal flow ratio of 1AP to TcSS1+TcSS2 is determined. Changing the combination of HNO₃ concentration and flow ratio can not remarkably improve the decontamination coefficient of Tc in TcS section if the overall consumption of HNO₃ is fixed. The lower concentration of nitric acid of TcSS2 is benefit for the decrease of the nitric acid concentration of TcSP and the reduction of the loss of U and Pu.