Simulation of nuclear-fuel solvent-extraction reprocessing 7. Separation of macroscopic amounts of plutonium and uranium by displacement reextraction of plutonium in reprocessing fast-reactor fuel (section 1)

Conclusions

These data have been obtained from simulating displacement reextraction in a system with two inputs (system for reprocessing a fast-reactor fuel), and they show that it is possible to obtain a uranium extract with not more than 100 μg Pu/kg U in a counter current system with 18 stages to provide partial separation of the uranium and plutonium by reprocessing of an organic solution containing U⁺ Pu (10 ∶ 1) with 64% saturation in the sum of the metals to produce reextract containing plutonium with U : Pu≤3 and over 99.99% extraction of the uranium; this requires 90 g/liter of uranium in the reextractant and the parameters n=2.06−2.00 ($X_{HNO_3 }^0$=0.3 M); n=1.82−1.87 ($X_{HNO_3 }^0$=0.5 M); n=1.61−1.78 ($X_{HNO_3 }^0$=1.0 M).

Full data obtained from the simulation are to be found in [5], from which one can extract the parameters of the working state of the extractor and other data on the separation of uranium and plutonium, e.g., for other specifications for the plutonium level in the uranium. The next part of the present study will be concerned with engineering solutions that can extend the range of conditions that provide the appropriate output parameters within specified ranges and thereby improve the reliability in operating the process in the optimal region.