Abstract: In a first step, uranium hexafluoride gas is reacted with steam in a first region of a vessel. In a second step, the oxyfluoride UO.sub.2 F.sub.2 obtained in the first step is converted to UO.sub.2 in a two-stage reduction process in which it is first contacted with a mixture of hydrogen gas and steam in one zone of the second region of the vessel, then contacted with the hydrogen gas in another zone of the second region.

Abstract: The present invention is directed to compositions of matter having the formula M.sub.2 UO.sub.2 F.sub.2 where each M is any alkali metal ion or mixtures thereof. The present invention is also directed to electrochemical cells having anodes containing anode-active alkali metal, electrolytes capable of conducting ions of said alkali metal, and cathodes containing cathode-active material having the formula M.sub.2 UO.sub.2 F.sub.2 where each M is any alkali metal ion or mixtures thereof. In another embodiment the cathode-active material has the formula UO.sub.2 F.sub.2.

Abstract: A nitrided alloy of uranium and zirconium is provided which consists of a single-phase UN structure containing a dissolved amount of Zr as ZrN, effective to inhibit dissociation of the UN phase.

Abstract: A continuous, four stage fluidized bed process for converting uranium hexafluoride (UF.sub.6) to ceramic-grade uranium dioxide (UO.sub.2) powder suitable for use in the manufacture of fuel pellets for nuclear reactors is disclosed. The process comprises the steps of first reacting UF.sub.6 with steam in a first fluidized bed, preferably at about 550.degree. C, to form solid intermediate reaction products UO.sub.2 F.sub.2, U.sub.3 O.sub.8 and an off-gas including hydrogen fluoride (HF). The solid intermediate reaction products are conveyed to a second fluidized bed reactor at which the mol fraction of HF is controlled at low levels in order to prevent the formation of uranium tetrafluoride (UF.sub.4). The first intermediate reaction products are reacted in the second fluidized bed with steam and hydrogen at a temperature of about 630.degree. C. The second intermediate reaction product including uranium dioxide (UO.sub.

Abstract: Process for the preparation of fine particle size uranium dioxide from a uranium trioxide feed comprising the following steps:A. reacting solid uranium trioxide with aqueous ammonium nitrate to form an insoluble ammonium uranateB. neutralizing the thus formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uraniumC. recovering the thus formed precipitates in a dry state andD. reducing the dried precipitate to uranium dioxide.

Abstract: A three stage fluidized bed process for converting uranium hexafluoride (UF.sub.6) to a ceramic-grade uranium dioxide (UO.sub.2) powder by first, reacting hydrogen and steam with UF.sub.6 in a first fluidized bed in a temperature range of from about 475.degree. to 600.degree. C to form solid intermediate products UO.sub.2 F.sub.2 and U.sub.3 O.sub.8 ; second, reacting hydrogen and steam with the intermediate products in a second fluidized bed at a temperature ranging from about 575.degree. to about 675.degree. C to produce a second group of intermediate products including UO.sub.2 F.sub.2, U.sub.3 O.sub.8, and UO.sub.2 ; and, third, reacting hydrogen and steam with the second group of intermediate products in a third fluidized bed at a temperature of 575.degree. to 675.degree. C to produce ceramic grade UO.sub.2 powder having low residual content of fluorides and other foreign materials.

Abstract: An actinide dioxide, e.g., uranium dioxide, plutonium dioxide, neptunium dioxide, etc., is prepared by reacting the actinide nitrate hexahydrate with sodium dithionite as a first step; the reaction product from this first step is a novel composition of matter comprising the actinide sulfite tetrahydrate. The reaction product resulting from this first step is then converted to the actinide dioxide by heating it in the absence of an oxygen-containing atmosphere (e.g., nitrogen) to a temperature of about 500.degree. to about 950.degree. C. for about 15 to about 135 minutes. If the reaction product resulting from the first step is, prior to carrying out the second heating step, exposed to an oxygen-containing atmosphere such as air, the resultant product is a novel composition of matter comprising the actinide oxysulfite tetrahydrate which can also be readily converted to the actinide dioxide by heating it in the absence of an oxygen-containing atmosphere (e.g., nitrogen) at a temperature of about 400.degree.

Abstract: Process and apparatus for producing ammonium diuranate (ADU) from uranium hexafluoride (UF.sub.6) wherein gaseous UF.sub.6 is first hydrolyzed, then partially neutralized with aqueous ammonium hydroxide to a pH of from 5 to 6, the resultant solution is conveyed to a precipitation vessel wherein it is admixed with additional aqueous ammonium hydroxide to a pH of from 9.8 to 10.

Abstract: A process for treating the aqueous effluents that are produced in converting gaseous UF.sub.6 (uranium hexafluoride) into solid UO.sub.2 (uranium dioxide) by way of an intermediate (NH.sub.4).sub.4 UO.sub.2 (CO.sub.3) .sub.3 ("AUC" Compound) is disclosed. These effluents, which contain large amounts of NH.sub. 4.sup.+ (ammonium), CO.sub.3.sup.-.sup.- (carbonate), F.sup.- (fluoride), and a small amount of U (uranium), are mixed with H.sub.2 SO.sub.4 (sulfuric acid) in order to expel CO.sub.2 (carbon dioxide) and thereby reduce the carbonate concentration. The uranium is precipitated through treatment with H.sub.2 O.sub.2 (hydrogen peroxide) and the fluoride is easily recovered in the form of CaF.sub.2 (calcium fluoride) by contacting the process liquid with CaO (calcium oxide). The presence of SO.sub.4.sup.-.sup.- (sulfate) in the process liquid during CaO contacting seems to prevent the development of a difficult-to-filter colloid. The process also provides for NH.sub.3 (ammonia) recovery and recycling.

Abstract: A pulsed flow process for the reduction of UF.sub.6 where the process may be continuous or batch starting without a seed bed. The initial amplitude and frequency of the pulsed flow is altered as a bed of particle-form material is formed and thereafter the particle-form product of the reaction is removed from the reaction zone.

Abstract: A process for converting uranium hexafluoride (UF.sub.6) to uranium dioxide (UO.sub.2) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed.

Abstract: A method of dehalogenating a particulate composition in a calciner having a heating zone and a cooling zone is presented in which a dehalogenating atmosphere flows through the calciner, including a constricted zone in the calciner, countercurrent to the movement of the composition through the calciner. There is practiced a step of constricting the passage of the controlled atmosphere to a zone of greater flow velocity so that the flow of the dehalogenating atmosphere through the constricted zone substantially minimizes diffusion into the cooling zone of the gaseous impurities removed from the particulate composition in the heating zone.

Abstract: Uranium is separated from contaminating cations in an aqueous liquor containing uranyl ions. The liquor is mixed with sufficient recycled uranium complex to raise the weight ratio of uranium to said cations preferably to at least about three. The liquor is then extracted with at least enough non-interfering, water-immiscible, organic solvent to theoretically extract about all of the uranium in the liquor. The oganic solvent contains a reagent which reacts with the uranyl ions to form a complex soluble in the solvent. If the aqueous liquor is acidic, the organic solvent is then scrubbed with water. The organic solvent is stripped with a solution containing at least enough ammonium carbonate to pecipitate the uranium complex. A portion of the uranium complex is recycled and the remainder can be collected and calcined to produce U.sub.3 O.sub.8 or UO.sub.2.

Abstract: Uranium is separated from contaminating metal ions in an aqueous feed liquor containing the uranyl ion. The liquor is extracted with a first, non-interfering, waterimmiscible, organic solvent containing a reagent which reacts with the uranyl ion to form a complex soluble in the organic solvent. The organic solvent is scrubbed with water if necessary, then stripped with a stripping liquor of an aqueous sulfuric acid liquor having a pH of about 0.5 to about 6 containing a reducing ion or an aqueous carbonate solution having a pH of about 8 to about 9. If the sulfuric acid liquor is used the stripped uranous ion is oxidized and the sulfuric acid liquor is diluted to prevent the precipitation of a uranium complex. The stripping liquor is extracted with an amine liquor comprising a second, noninterfering, water-immiscible, organic solvent and a tertiary or quaternary amine. The amine liquor is stripped with an ammonium carbonate solution to precipitate a uranium complex.