Abstract: Embodiments of a series-coupled fluidized bed reactor unit are provided. In one embodiment, the reactor unit includes primary and secondary reactors. The primary reactor includes a reaction vessel, a gas distributor fluidly coupled to the reaction vessel, and a cyclonic plenum assembly. The cyclonic plenum assembly includes a plenum assembly housing, which is fluidly coupled to the gas distributor and which has an annular sidewall; and a gas/solids inlet pipe, which fluidly couples a partially-reacted gas outlet of the secondary reactor to the plenum assembly housing. The gas/solids inlet pipe is tangentially positioned with respect to the annular sidewall of the plenum assembly housing to induce vortex flow within the plenum assembly housing of the partially-reacted gas received from the secondary fluidized bed reactor through the gas/solids inlet pipe to promote the cyclonic separation of entrained solids from the partially-reacted gas prior to entry into the gas distributor.

Abstract: Embodiments of a series-coupled fluidized bed reactor unit are provided. In one embodiment, the reactor unit includes primary and secondary reactors. The primary reactor includes a reaction vessel, a gas distributor fluidly coupled to the reaction vessel, and a cyclonic plenum assembly. The cyclonic plenum assembly includes a plenum assembly housing, which is fluidly coupled to the gas distributor and which has an annular sidewall; and a gas/solids inlet pipe, which fluidly couples a partially-reacted gas outlet of the secondary reactor to the plenum assembly housing. The gas/solids inlet pipe is tangentially positioned with respect to the annular sidewall of the plenum assembly housing to induce vortex flow within the plenum assembly housing of the partially-reacted gas received from the secondary fluidized bed reactor through the gas/solids inlet pipe to promote the cyclonic separation of entrained solids from the partially-reacted gas prior to entry into the gas distributor.

Abstract: A fluidized bed reactor comprising a reaction column having a fluid portion; a gas inflow means for flowing a gas upwardly from the fluid portion of the reaction column; a particle feed means for feeding particles to the fluid portion of the reaction column; a cyclone capable of separating particles from the gas flowing upwardly from the fluid portion of the reaction column, the cyclone being located within the reaction column and being in communication with the gas flowing upwardly, wherein the cyclone comprises a cyclone body having an inlet, a gas outlet, and a particle drop port; and a particle discharge pipe having an upper part connected to the particle drop port of the cyclone body, and a lower part, wherein the particle discharge pipe is located substantially outside of the reaction column.

Abstract: A fluidized bed reactor comprising a reaction column having a fluid portion; a gas inflow means for flowing a gas upwardly from the fluid portion of the reaction column; a particle feed means for feeding particles to the fluid portion of the reaction column; a cyclone capable of separating particles from the gas flowing upwardly from the fluid portion of the reaction column, the cyclone being located within the reaction column and being in communication with the gas flowing upwardly, wherein the cyclone comprises a cyclone body having an inlet, a gas outlet, and a particle drop port; and a particle discharge pipe having an upper part connected to the particle drop port of the cyclone body, and a lower part, wherein the particle discharge pipe is located substantially outside of the reaction column.

Abstract: The present invention includes a composition of LiF—ThF4—UF4—PuF3 for use as a fuel in a nuclear engine.

Abstract: The invention relates to a particle blend comprising mainly or consisting of an oxide phase of the pseudo-brookite type comprising at least titanium and aluminum, said blend being obtained from at least two particle size fractions, namely a coarse particle size fraction, the median diameter d50 of which is greater than 12 microns, and a fine particle size fraction, the median diameter d50 of which is between 0.5 and 3 microns, the mass ratio of said coarse fraction to said fine fraction being between 1.5 and 20, limits inclusive, and the ratio of the median diameter of the coarse fraction to that of the fine fraction being greater than 12.

Abstract: The invention relates to a process for the chemical beneficiation of raw material containing tantalum-niobium such as wastes, scoria, concentrates and ores.

Abstract: The invention provides a series of techniques for processing uranium containing feed materials such as uranium ores, reprocessed uranium, uranium containing residues and uranium containing spent fuel. The processes described involve fluorination of uranium containing material, separation of the uranium containing material from other materials based on ionization thereof with the non-ionized fluorine containing material being recycled. Metallic uranium and/or plutonium and/or fission products may result. The technique offers advantages in terms of the range of materials which can be reprocessed and a reduction in the number of complexity of stages which are involved in the process.

Abstract: Fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel to produce fluorides of uranium and plutonium, and recovering the fluorides using a difference in volatility behavior. The method includes steps of: subjecting a mixture of UO2 and PuO2 with hydrogen fluoride mixed with hydrogen to HF-fluorinate uranium and plutonium into UF4 and PuF3; subjecting UF4 and PuF3 with a fluorine gas to F2-fluorinate uranium and plutonium into UF6 and PuF6; and fractionating UF6 and PuF6 using a difference in phase change of obtained UF6 and PuF6, removing a part of UF6, and volatilizing the remaining UF6 and PuF6 at the same time. By such a reprocessing method, PuF4 hard to undergo a reaction is prevented from being formed as an intermediate fluoride, the material of a reactor is hard to be corroded, and a consumption of expensive fluorine gas is reduced.

Abstract: Fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel to produce fluorides of uranium and plutonium, and the fluorides are recovered using a difference in volatility behavior. The spent oxide fuel is subjected to a reaction with an HF gas, whereby uranium, plutonium and most impurities are converted into solid fluorides having low valences or remained as oxides to inhibit volatilization thereof, and then in an F2 fluorination step, the HF fluorination product is subjected to a reaction with a fluorine gas in two stages: one at a low temperature and the other at a high temperature, whereby a certain amount of gaseous uranium and volatile impurities are separated with plutonium kept in a solid form in the first stage, and mixed fluorides of remaining uranium and plutonium are fluorinated into hexafluorides at the same time in the second stage. By such a reprocessing method, plutonium enrichment can be adjusted, uranium and plutonium can be purified, and steps are simplified as well.

Abstract: The invention provides a method of separating uranium from at least fission products in irradiated nuclear fuel, said method comprising reacting said irradiated nuclear fuel with a solution of ammonium fluoride in hydrogen fluoride fluorinating said reacted irradiated nuclear fuel to form a volatile uranium fluoride compound and separating said volatile uranium fluoride compound from involatile fission products. The invention thus provides a reprocessing scheme for irradiated nuclear fuel. The method is also capable of reacting, and breaking down Zircaloy cladding and stainless steel assembly components. Thus, whole fuel elements may be dissolved as one thereby simplifying procedures over conventional Purex processes.

Abstract: A single furnace loading cycle method for sintering at least one product. The method comprises the steps of placing at least one product into a ventable/sealable box, which box is placed inside a furnace. The box is vented inside the furnace at a first temperature range, and then the box is sealed with the at least one product inside the box in a second temperature range, wherein the second temperature range is higher than the first temperature range, and wherein the step of sealing occurs after the step of venting without removing the box from the furnace.

Abstract: The invention relates to a process and a catalyst composition for the destruction of volatile organic compounds (VOCs). The process includes the step of contacting the VOCs with an oxygen-containing gas in the presence of a catalyst which is a metal-exchanged, metal-impregnated aluminosilicate zeolite with at least one exchanged metal in the zeolite being selected from the group consisting of Ti, V, Cr, Co, Ni, Cu, Fe, Mo, Mn, Pd, and Pt, and at least one impregnated metal in the zeolite being selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Pd and Pt, and wherein the difference between the exchanged metal and the impregnated metal varies the temperature necessary to promote oxidation of the compounds and for a contact time sufficient to oxidize the compounds. The process reaction temperature can vary from about 100.degree. C. to about 650.degree. C. and the contact time can vary from about 0.01 to 20 seconds. Preferredly, the reaction temperature is from about 150.degree. C.

Abstract: Process for the treatment of a metal alloy based on uranium, generally in highly enriched form and other metallic elements, comprising a fluorination treatment with the aid of at least one fluorine-containing gas, optionally with an intermediate fluorination with the aid of a fluoric compound, a distillation treatment of the gaseous fluoride flow obtained in order to obtain pure uranium hexafluoride, as well as a mixing treatment of said hexafluoride with another more depleted hexafluoride to obtain the desired final isotopic content.

Abstract: A process and a sorbent/catalyst composition are described for the oxidation of volatile organic compounds. The process uses the steps of adsorbing a volatile organic compound in a first segment of a sorbent/catalyst bed at an adsorption temperature, followed by sequential heating of an opposed second segment of a sorbent/catalyst bed, downstream of the first segment, from an initial temperature to an oxidation temperature, desorbing the volatile organic compound from the first segment of the bed by heating, and cooling of the first and second segments of the bed respectively. The sorbent/catalyst contains an adsorption segment, e.g., metal oxides, unexchanged zeolites, carbon and polymeric resins, etc., and a catalytic segment for the subsequent catalytic oxidation of the compounds.

Abstract: A process for the selective electrofluorination of metallic alloy based on U characterized by effecting a selective anodic reaction on at least one of the components of the alloy by means of a controlled anodic voltage applied to the alloy in a bath of molten fluorides.

Abstract: A multichamber type fluid bed reaction apparatus has a series of chambers formed by dividing the fluid bed part and the wind box part thereof with particular walls. Each reaction chamber is supplied with a reaction gas whose composition, flow amount and temperature can be selected arbitrarily. A fluid bed, a moving bed or a fixed bed may be used in each divided chamber. Regulation of particle formation, gas-particle reaction and amount of particles transferring between the chambers results in an improvement of efficiency and a simplification of the apparatus.

Abstract: A method of producing a high density, low hygroscopic green salt from hydrated green salt includes heating a charge of hydrated green salt in a nonreactive atmosphere to a first temperature above the boiling point of water to drive off free water; heating the charge in a nonreactive atmosphere to a second temperature higher than the first temperature to drive off the water of crystallization present in the green salt; heating the charge in a nonreactive atmosphere to a third temperature higher than the second temperature to induce anhygroscopicity of the charge; and cooling the charge to approximately 400.degree. F. or less in a protective atmosphere to prevent atmospheric oxidation and hydrolysis.

Abstract: A compound MF.sub.n, where M is a metal and n is the valency of the metal and has a value between 1 and 6, is subjected to a thermal plasma at a temperature in excess of 3000 K to dissociate it into the metal and fluorine. Also present in the reactor is an added reactant that will react with the metal or the fluorine to prevent their recombination so that there is formed fluorine gas or a fluoride other than the fluoride of the metal M.

Abstract: In a method of producing uranium (IV) fluoride, a feedstock comprising uranium metal or alloy is dissolved in hydrochloric acid and hydrofluoric acid to produce a clear solution. The solution is heated and excess hydrofluoric acid added to produce a precipitate comprising uranium (IV) fluoride.

Abstract: A process for preparing uranium tetrafluoride by reacting a uranous solution with a hydrofluoric acid solution in a fluorination precipitation tank is provided. A cylindrical inner tube having upper and lower ends opened is disposed in the tank in the longitudinal direction thereof. An agitator is arranged within the inner tube to generate a descending or ascending stream inside the inner tube and a ascending or descending stream outside the inner tube, thereby producing a circulation of reaction liquor in the tank. The uranous solution and the hydrofluoric acid solution are introduced into the tank from the upper part thereof and the produced uranium tetrafluoride crystals are withdrawn from the lower part of the tank together with a part of the reaction mother liquor. The amount of the hydrofluoric acid solution added to the uranous solution is adjusted so that the fluorine concentration in the reaction mother liquor in the tank is maintained at 2 to 4 g/l.

Abstract: A process for the preparation of uranium tetrafluoride by reduction of gaseous uranium hexafluoride using: (1) sulphur vapor with a minimum of halogen and/or a halide, chosen from among Cl.sub.2, Br.sub.2, S.sub.2 F.sub.2, SCL.sub.2, S.sub.2 Cl.sub.2, and S.sub.2 Br.sub.2 ; or (2) a minimum of one sulphur halide chosen from among S.sub.2 F.sub.2, SCL.sub.2, S.sub.2 CL.sub.2, and S.sub.2 Br.sub.2. The ratio R of the total number of gram-atoms of sulphur present during the reduction reaction to the number of gram-moles of UF.sub.6 is at least 0.6.

Abstract: A method and apparatus are provided for producing green salt (UF.sub.4) from uranium-bearing metal pieces. The uranium-bearing metal pieces are dissolved in a first aqueous solution containing hydrochloric acid and between 0.5% and 5% fluoboric acid to provide a second aqueous solution which includes uranium (U.sup.+4), chlorine ions (Cl.sup.-) and hydrochloric and fluoboric acids. Hydrofluoric acid is added to the second aqueous solution to precipitate green salt out of that solution and provide a third aqueous solution which contains hydrochloric acid. The green salt is then separated from the third aqueous solution.

Abstract: A process for the recovery of uranium which has been extracted from phosphate-bearing solutions by means of an organic solvent and which is re-extracted from said solvent by means of hydrofluoric acid is disclosed.The process is characterized in that sodium ions are introduced into the solution of hydrofluoric acid, while aluminum and magnesium ions may also be added to the sodium ions. That solution may be produced by recycling of a fraction of the suspension of fluoride from the re-extraction step, after having separated the solvent, and to which a make-up of sodium, aluminum and magnesium ions and hydrofluoric acid was added.

Abstract: A method for monitoring the stack gases of a purge cascade of a gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases.

Abstract: A method and apparatus are provided for producing green salt (UF.sub.4) from uranium-bearing metal pieces. The uranium-bearing metal pieces are dissolved in a first aqueous solution containing hydrochloric and fluoboric acids to provide a second aqueous solution which includes uranium (U.sup.+4), chlorine ions (Cl.sup.-) and hydrochloric and fluoboric acids. Hydrofluoric acid is added to the second aqueous solution to precipitate green salt out of that solution and provide a third aqueous solution which contains hydrochloric acid. The green salt is then separated from the third aqueous solution.

Abstract: In a process for the production of uranium tetrafluoride (UF.sub.4), uranic oxides, UO.sub.3 and U.sub.3 O.sub.8, are dissolved in dilute sulphuric acid (H.sub.2 SO.sub.4) and hydrofluoric acid (HF) is added to produce a uranyl fluoride-sulphate solution which is electrolytically reduced to uranous fluoride-sulphate complexes from which hydrated uranium tetrafluoride is precipitated by the addition of dilute HF at elevated temperature (preferably above 90.degree. C.). The uranyl fluoride-sulphate solution can alternatively be produced by dissolving uranyl fluoride in H.sub.2 SO.sub.4 or from uranyl sulphate solutions (derived from solvent extraction or ion exchange purification processes) conditioned with HF.

Abstract: A process for the incremental enrichment of deuterium and/or tritium in a material which is suitable for the isotope exchange of deuterium and tritium with hydrogen, and an arrangement for the implementation of the process. The process and arrangement for the enrichment of deuterium and/or tritium in water which, in addition to a high transport speed for the molecules which participate in the isotope exchange, evidences a high enrichment factor for each enrichment stage and a high yield, so that at a relatively small number of stages and low energy consumption there is attainable an overall high degree of enrichment. For each enrichment stage, water containing deuterium and/or tritium is introduced into a carrier gas flow, reduced and set to a hydrogen (H.sub.2) partial pressure of maximally 100 mbar.

Abstract: A recovery process of uranium comprising:(1) extracting uranium ions with an organic solvent containing one or more compounds selected from the group consisting of alkyl phosphoric acid, alkyl-aryl phosphoric acid, alkyl dithio phosphoric acid, aryl dithio phosphoric acid, neutral phosphoric acid ester and alkyl amine together with a petroleum hydrocarbon as a diluent; and(2) stripping the uranium ions in the resultant organic solvent from the step (1) to an aqueous phase with contact of an aqueous solution containing one or more compounds selected from the groups of NH.sub.4 F, NH.sub.4 HF.sub.2, KF or KHF.sub.2.

Abstract: The lifetime of the photo redox induced disproportionation products of ruthenium polypiridine complexes is significantly increased from about two milliseconds in a liquid phase to greater than thirty-six hours by depositing the complexes in the pores of thirsty glass, thus making possible their use in chemical reactions such as the reduction of water to produce hydrogen at room temperatures.A photochemical reaction system is thereby formed within the situs of the porous glass which adsorbs the photo redox agent and permits diffusion of hydrogen out as an end product while retaining its transparency and characteristics for long periods of use.The porous glass medium withstands high temperatures and processes of organizing the reaction system by depositing as complementary layers various agents and catalysts necessary in a chemical reaction system from solutions and at temperatures otherwise incompatible with liquid redox agents or other site materials.

Abstract: Method and apparatus for separating isotopes in an isotopic mixture of atoms or molecules by increasing the mass differential among isotopic species. The mixture containing a particular isotope is selectively irradiated so as to selectively excite the isotope. This preferentially excited species is then reacted rapidly with an additional preselected radiation, an electron or another chemical species so as to form a product containing the specific isotope, but having a mass different than the original species initially containing the particular isotope. The product and the remaining balance of the mixture is then caused to flow through a device which separates the product from the mixture based upon the increased mass differential.

Abstract: Irradiated nuclear fuels consisting primarily of plutonium compounds and/or uranium compounds such as oxides, carbides, nitrides are converted in accordance with the method to plutonium hexafluoride and/or uranium hexafluoride. In a first step, the compounds are contacted within a first zone of an enclosure with a gas mixture containing at least one fluorination reagent. In a second step, the remainder of the compounds which have not been converted to fluorides during the first step is contacted directly within a second zone of the enclosure with a bed which has been fluidized by means of a gas mixture containing at least one fluorination reagent.

Abstract: There is provided a process for continuous preparation of uranium tetrafluoride hydrate which comprises the steps of continuously feeding uranous solution and hydrofluoric acid into the lower section of a reaction vessel to produce crystal particles of uranium tetrafluoride hydrate causing the crystal particles to float up and be suspended in the upper section of the reaction vessel by agitation; in which section the crystal particles grow and then precipitating and discharging the thus grown crystal particles from the bottom of the vessel, while causing waste solution to overflow from the top of the vessel. There is also provided an apparatus to accomplish the aforementioned process.

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: The reduction of UF.sub.5 to UF.sub.4 in a molten fluoride salt by sparging with hydrogen is catalyzed by metallic platinum. The reaction is also catalyzed by platinum alloyed with gold reaction equipment.

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 novel method is disclosed for producing a pure uranium trifluoride efficiently. Said method is characterized by heating a mixture of uranium tetrafluoride and uranium nitride in an inert gas stream or under vacuum.

Abstract: A process which comprises reacting at a temperature above 100.degree.C. a metal oxide, hydroxide or a mixture thereof with aqueous fluosilicic acid, said fluosilicic acid having a concentration of about 10 to 45% by weight, to form gaseous silicon tetrafluoride and the corresponding metal fluoride and recovering said metal fluoride from the reaction medium.

Abstract: The production of UF.sub.6 in which UF.sub.4 is reacted with air or oxygen in the presence of a catalyst at 500.degree. to 700.degree.C. The solid byproduct of this reaction is reduced with hydrogen in the presence of a catalyst at 400.degree. to 600.degree.C. Fresh UO.sub.3 may also be reduced with hydrogen in the same reactor as UO.sub.2 F.sub.2. The reduction product or products are reacted with hydrogen fluoride at 400.degree. to 600.degree.C, producing UF.sub.4 which would be recycled for further reaction to produce UF.sub.6.

Abstract: A process for making uranium metal from uranium oxide by first fluorinating uranium oxide to form uranium tetrafluoride and next electrolytically reducing the uranium tetrafluoride with a carbon anode to form uranium metal and CF.sub.4. The CF.sub.4 is reused in the fluorination reaction rather than being disposed of as a hazardous waste.