The radiolytic changes in oxidation state for solutions of initially Np(V) and/or Np(VI) were investigated by gamma-irradiation in conjunction with UV/Vis spectroscopy of the aqueous phase. Samples were irradiated in varying concentrations of nitric acid, and with or without the presence of 30 % TBP in dodecane. At short irradiation...
Neptunium, with its rich redox chemistry, has a special position in the chemistry of actinides. With a decades-long history of development of aqueous separation methods for used nuclear fuel (UNF), management of neptunium remains an unresolved issue because of its not clearly defined redox speciation. Neptunium is present in two,...
Spent nuclear fuel (SNF) resultant from the generation of nuclear power is a chemically and radiologically diverse system which is advantageous to chemically process prior to geologic disposal. Hydrometallurgy is the primary technology for chemical processing for light water reactor spent fuels, where spent fuel is dissolved in an acid...
Aqueous complexation of Th(IV), U(IV), Np(IV), Pu(III/IV), and Ce(III/IV) with DTPA was studied by potentiometry, absorption spectrophotometry, and cyclic voltammetry at 1 M ionic strength and 25 °C. The stability constants for the 1:1 complex of each trivalent and tetravalent metal were calculated. From the potentiometric data, we report stability...
Carboxylic acids have played an important role in the field of actinide (An) and lanthanide (Ln) separations and the reprocessing of irradiated nuclear fuel. Recent bench-scale experiments have demonstrated that 3-carboxy-3-hydroxypentanedioic acid (citric acid) is a promising aqueous complexant that can effectively aid in the separation of transition metals from...
Used Nuclear Fuel (UNF) contains transuranic (TRU) elements and numerous fission products as a result of the uranium fission process and neutron activation that occur in commercial light water power reactors. Recent environmental and nuclear proliferation concerns have spawned the development of advanced reprocessing techniques to close the nuclear fuel...
Waste products from industry have often been disposed in
landfills without regard for any beneficial uses of the product in
agricultural production. This research was conducted to determine
the effect of a refractory metal processing waste product on (a) soil
chemical and physical properties, (b) perennial ryegrass forage
quality and...
An analytical technique has been developed for the determination of methylmercury compounds in environmental samples. The technique is based on a two-stage procedure. In the first stage, methylmercury compounds are isolated from the sample matrix as methylmercury chloride (MeRgCl) by distillation. The distillation procedure is based on a series of...