Abstract:
The control of path of Np in the purex process by using cascade count-current extraction method is investigated. Well-defined conditions for recovery, separation and purification of Np from the stream 2DW of 2nd. U-cycle are proposed.The factors effecting the process, such as the HNO3 concentration of the feed, the degree of uranium saturation of organic phase, the concentration of H2C2O4, the acidic concentration of stripping solution and the temperature of strip are discussed.The recovery of Np in 2DW stream was 97-99.9%. The loss of uranium to 2DW stream was less than 0.2 g/1. In the 3D extraction, jostactor, recovery of Np was 99-99.6%. The y-decontamination factor of Np from the mixture fission product elements was about 1×102-3×102. In the 2N stripping contactor recovery of Np was 99.3-99.5%. Separationfactor of Np from U(i.e. SFU) was 1.7 × 103-2×102, SFth---40 - 5.4×102, SFPu-----2.3-5.3. The decontamination factor of Np from the γ-emitters was about 1.4 -1.6. The main factor limitting the overall decontamination of Np was 95Zr as well as 106Ru and 95Nb.