In this problem, we examine the process of recovering fission materials from spent nuclear fuel rods.

In this problem, we examine the process of recovering fission materials from spent nuclear fuel rods. This is usually referred to as reprocessing of the fuel to recover plutonium (Pu) and the active isotope of uranium (U_235 ). Reprocessing can be done by separation of the soluble isotope nitrates from a solution in nitric acid by a solvent such as a 30% solution of tributyl phosphate (TBP) in dodecane (C_12H_26) in which the nitrates are preferentially soluble. Industrial reprocessing of nuclear fuels is done by countercurrent operation of many liquid-liquid separation stages. These separation stages consist of well-mixed contacting tanks, where is exchanged between two immiscible liquid phases, and separation tanks, where the organic and aqueous phases are separated. A schematic of a separation stage is shown in Figure 5.25a