Back-extraction phase
The purpose of the second stage of the process is to recover the uranium and plutonium from the kerosene. The kerosene is brought into contact with pure water and the resulting mixture agitated as before. TBP is no longer effective, as the water is not sufficiently acidic. As a result, it releases the uranium and plutonium, which enter the pure water. The water and kerosene naturally separate when the mixture is allowed to rest. All that remains is to transfer the kerosene. This results in water containing just the uranium and plutonium, and the kerosene-TBP mixture, which can be reused (almost indefinitely) in subsequent extraction operations.
IN2P3 (I. Billard)