Control of extraction cascades

Plutonium purification proceeds by reducing the aqueous phase pH that oxidizes the plutonium to Pu" +, which then extracts into the TBP phase. Impurities stay in the aqueous phase. The TBP phase strip-ping/extraction cycle is repeated to complete the plutonium purification. The uranium is purified using the same TBP/nitric acid extraction/stripping cycle. Careful control of the each element s oxidation state in the extraction cascade produces the plant-scale separations of uranium from plutonium of 10 . Fission product decontamination factor was 10. The plutonium and uranium recovery is about 99.9% with 95% of the nitric acid values and 99.7 /o of the organic solvent recycled. ... [Pg.2649]

Artificial cascades performed with isolated enzymes in vitro (cell-free extracts or purified enzymes) provide several advantages compared to artificial cascades in recombinant cells. Multi-enzyme reactions based on isolated enzymes can easily be controlled in a desired maimer, including key factors such as enzyme combination in defined ratios and adjustment of specific reaction component ratios (i.e., cofactors). This allows a more detailed control of the biocatalytic multi-enzyme system in contrast to in vivo cascades where the above-mentioned factors are much more difficult to control. [Pg.116]

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