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The electrochemical reduction of uranium oxide in the treatment of spent nuclear fuel requires a characterization of the LiCl-Li2O salt used as a reaction medium. Physical properties, melting and vaporization are important for the application of the salt and thus they have been investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG), respectively. Experimental data suggest LiCl and Li2O compound formations, leading to a melting point depression of the LiCl and a co-vaporization of the LiCl-Li2O salt. [ABSTRACT FROM AUTHOR]

The Advanced Spent Conditioning Process (ACP) developed by the KAERI is based on pyrometallurgy and the electrolytic reduction plays a central role in transforming spent oxide fuels into metals. The constituents of the spent fuels are distributed between a salt and a reduced metal phase during electrolysis. Lithium metal is produced in a molten LiCl-Li2O cell and then it reacts with the metal oxides of the spent fuel producing Li2O and reduced metals. By focusing on the activity of Li2O and the electric potential, the electrolytic reduction process of the ACP is discussed. Thermodynamic considerations are defined and operation conditions are proposed including Li2O activity and cell potential. [ABSTRACT FROM AUTHOR]

The electrolytic reduction of U3O8 powder was carried out using LiCl-Li2O molten salt in a 20-kg U3O8 batch cell to verify the feasibility of the process. As the current passes the cell, the decomposition of Li2O and the reduction of U3O8 occur simultaneously in a cathode assembly and oxygen gas evolvs at the anode. The results from a 20-kg U3O8 scale cell were compared with data obtained from a bench scale cell. The results suggest a successful demonstration of this process, exhibiting a reduction conversion of U3O8 of more than 99% in a batch. [ABSTRACT FROM AUTHOR]

Abstract: An electrolytic reduction of U3O8 in a molten LiCl–Li2O salt was investigated using the electrochemical techniques of cyclic voltammetry (CV) and chronopotentiommetry (CP). The electrolytic reduction of U3O8 powder exhibited a different behavior when the initial current density was higher than for 10g U3O8/batch run. Two kinds of reduction mechanisms, an electro-metallothermic reduction (EMR) and a direct electrochemical reduction (DER) were adopted to explain the resultant behavior. Current efficiencies and reduction products were obtained by a series of constant current runs. Current efficiencies, evaluated for a reduction side, were estimated to be more than 75% throughout a series of constant current runs and lithium uranium oxides (lithium uranates) were detected during the U3O8 reduction to metallic uranium. [Copyright &y& Elsevier]

We report a case of angiofibroma confined to the pterygoid muscle plane without involvement of the sphenopalatine foramen or nasopharynx. The lesion was demonstrated on CT, MR, and angiography with typical findings of a hypervascular mass and was surgically resected after embolization.