Plutonium processing chemical applications

The fission product and encapsulation plant (FPCE) to be built by Isochem, Inc.y in Washington state will produce fully encapsulated fission products for the commercial market. Among these, all of which are extractable from Hanford s plutonium process residues, is cesium-137, a 600-kv. gamma emitter of interest to the process irradiation industry. Isochem will offer cesium in large production quantities and low cost to irradiators of foods, woods, chemicals, etc. Its 30-year half-life promises economies in source array replenishment to compensate for decay. Cesium thus becomes an economic contender for current and planned irradiation applications. 

The complex interrelationships of three types of chemical equilibria, namely oxidation-reduction, hydrolysis, and complexa-tion, as well as polymerization, a nonequilibrium process, determine the nature and speciation of plutonium in aqueous environmental systems. This paper presents a selective, critical review of the literature describing these processes. Although most research has been conducted under non-environmental conditions— that is, macro concentrations of plutonium and high acidities—the results in some cases are applicable to environmental conditions. In other cases the behavior is different, however, and care should always be exercised in extrapolating macro data to environmental conditions. 

Direct calcination of Pu(N03)4 involves no chemical separations that could remove impurities, so a highly pure plutonium nitrate feed solution is required. The plutonium dioxide product can be hydrofluorinated to PUF4, or it can be used as a feed for the formation of PUCI3. Direct calcination has received less industrial-scale application than the precipitation processes described above [C2]. 

Chen J, Zhu Y, Jiao R (1996) Sep Sci Technol 31 2723 Choppin GR, Rydberg J (1980) Nuclear chemistry, theory and applications. Pergamon, Oxford Choppin GR, Rydberg J, Liljenzin JO (1995) Radiochemistry and nuclear chemistry, theory and applications. Butterworth-Heinemann, Great Britain Coops MM, Knighton JB, Mullins LJ (1983) Pyrochemical processing of plutonium. In Carnall WT, Choppin GR (eds) Plutonium chemistry, ACS symposium series, vol 216. American Chemical Society, Washington DC, pp 381-400... 

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