REDUCTION STRIPPING OF PLUTONIUM(Ⅳ) WITH HYDROXYLAMINE NITRATE IN THE CENTRIFUGAL CONTACTOR

Reduction stripping of Pu(IV) with hydroxylamine nitrate under conditions of Purex 3B contactor is carried out with 16-stage mixer-centrifugal settler in laboratory scale. Results show that the apparent recovery of Pu is more then 99.9%. But there is great difference in the concentration of plutonium of every stage in extraction equipment at different temperature. For example, plutonium concentrations in organic phase of several stages near the organic effluent at 4550℃ are lower than that at 20-24℃. Thus, recovery efficiency of plutonium can be assured only for the former. However, plutonium will probably be lost, if operating conditions are fluctuated. In addition, plutonium accumulated in the extraction equipment increased appreciably for the case of 20-24℃. Therefore, in order to ensure recovery efficiency of Pu, reduction stripping of Pu should be made at higher temperature.