Purex partitioning schemes

Figure la. Classical Purex partitioning schemes—early partitioning (-) aqueous streams, (------------------------------------------------------) organic streams R. A., reducing agent TBP, n-tributyl phos-... 

Figure lb. Classical Purex partitioning schemes—late partitioning... 

A variation of the PUREX process is being proposed by the US Department of Energy as a possible alternative partitioning scheme for the transmutation of wastes. This aqueous process called UREX, only removes uranium from spent commercial LWR fuel and leaves plutonium in the HLW stream with the other minor actinides and fission products. Nonaqueous pyroprocessing, a variation of the ANL electrorefining process, is then proposed to be used to separate both the plutonium and minor actinides so that they can be transmuted in an ADS. For further information related to potential modifications of this process for other accelerator transmutation of waste applications, see ANL-99/15 (1999). 

Fig. 12.14 Schemes for partitioning Purex high-level waste, (a, data from Ref. 54 b, data from Ref. 55.)...

The location of the Pu-U partitioning step in Purex flow-sheets and the selection of specific operating variables (flow rates, concentrations, temperature) were generally determined by the type of fuel to be reprocessed, the subsequent waste management schemes, and the desired characteristics of the products. 

Figure 10.29 shows the principal steps in applying the Purex process to irradiated LMFBR fuel, step 7 of Fig. 10.28. The flow scheme and the compositions and locations of solvent, scrubbing, and stripping streams have been taken from the process flow sheet of a 1978 Oak Ridge report [Oil] describing a planned experimental reprocessing facility designed for 0.5 MT of uranium-plutonium fuel or 0.2 MT of uranium-plutonium-thoiium fuel per day. As that report gave process flow rates only for the uranium-plutonium-thorium fuel. Fig. 10.29 does not give flow rates for the uranium-plutonium fuel of present interest. This flow sheet shows the codecontamination step, in which flssion products are separated from uranium and plutonium the partitioning step, which produces an aqueous stream of partially decontaminated...

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