Abstract: A method of producing uranium nitride (e.g., uranium mononitride) and/or uranium-containing intermediates that can be used to further produce uranium nitride includes reacting a reaction mixture comprising uranium carbide with a gas comprising hydrogen and nitrogen, cooling the reaction mixture to a temperature suitable to produce a phase comprising U2N3, and heating the reaction mixture to a temperature suitable to convert the phase comprising U2N3 to a phase comprising UN. The method produces highly purified UN, is insensitive to excess carbon reactants, and can be readily integrated into existing uranium production facilities as part of a continuous process.

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

Abstract: The present invention provides a nuclear fuel comprising an actinide nitride such as 233U, 234U, 235U, 236U, 238U, 232Th, 239Pu, 240Pu, 241Pu, 242Pu, 244Pu, 239Np, 239Am, 240Am, 241Am, 242Am, 243Am, 244Am, 245Am, 240Cm, 241Cm, 242Cm, 243Cm, 244Cm, 245Cm, 246Cm, 247Cm, 248Cm, 249Cm, 259Cm, 245Bk, 246Bk, 247Bk, 248Bk, 249Bk, 250Bk, 248Cf, 249Cf, 250Cf, 251Cf, 252Cf, 253Cf, 254Cf, 255Cf, 249Es, 250Es, 251Es, 252Es, 253Es, 254Es, 255Es, 251Fm, 252Fm, 253Fm, 254Fm, 255Fm, 256Fm, 257Fm, 255Md, 256Md, 257Md, 258Md, 259Md, 260Md, 253No, 254No, 255No, 256No, 257No, 258No and 259No, and optionally fission products such as 97Tc, 98Tc and 99Tc, suitable for use in nuclear reactors, including those based substantially on thermal fission, such as light and heavy water reactors, gas-cooled nuclear reactors, liquid metal fast breeders or molten salt fast breeders. The fuel contains nitrogen which has been isotopically enriched to at least about 50% 15N, most preferably above 95%.

Abstract: The invention relates to a method for separating uranium(VI) from one or more actinides selected from actinides(IV) and actinides(VI) other than uranium(VI), characterized in that it comprises the following steps: a) bringing an organic phase, which is immiscible with water and contains the said uranium and the said actinide or actinides, in contact with an aqueous acidic solution containing at least one lacunary heteropolyanion and, if the said actinide or at least one of the said actinides is an actinide(VI), a reducing agent capable of selectively reducing this actinide(VI); and b) separating the said organic phase from the said aqueous solution. Applications: reprocessing irradiated nuclear fuels, processing rare-earth, thorium and/or uranium ores.

Abstract: A method of preparing an actinide nitride fuel for nuclear reactors is provided. The method comprises the steps of a) providing at least one actinide oxide and optionally zirconium oxide; b) mixing the oxide with a source of hydrogen fluoride for a period of time and at a temperature sufficient to convert the oxide to a fluoride salt; c) heating the fluoride salt to remove water; d) heating the fluoride salt in a nitrogen atmosphere for a period of time and at a temperature sufficient to convert the fluorides to nitrides; and e) heating the nitrides under vacuum and/or inert atmosphere for a period of time sufficient to convert the nitrides to mononitrides.

Abstract: The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as carbides and transition-metal, lanthanide and actinide oxides, using an aerodynamic levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Abstract: The present invention generally relates to the preparation of mixed actinide oxides, such as mixed oxides of uranium and plutonium (U, Pu) O2, by simultaneously coprecipitation and then calcinations.

Abstract: The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Abstract: The synthesis of actinide tetraborides including uranium tetraboride (UB4), plutonium tetraboride (PuB4) and thorium tetraboride (ThB4) by a solid-state metathesis reaction are demonstrated. The present method significantly lowers the temperature required to ≦850° C. As an example, when UCl4 is reacted with an excess of MgB2, at 850° C., crystalline UB4 is formed. Powder X-ray diffraction and ICP-AES data support the reduction of UCl3 as the initial step in the reaction. The UB4 product is purified by washing water and drying.

Abstract: A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g.

Abstract: A method of separating uranium and plutonium from a mixed solution containing uranium nitrate and plutonium nitrate comprises cooling the mixed solution to a temperature ranging from -40.degree. to -20.degree. C. to thereby selectively precipitate uranyl nitrate. The precipitated uranyl nitrate is separated from the solution while leaving plutonium nitrate to remain in the solution.

Abstract: A method of fabricating uranium dioxide (UO.sub.2) powder from uranium hexafluoride (UF.sub.6) is disclosed, which comprises(1) reacting UF.sub.6 gas with steam with controlling the temperature of reaction between said UF.sub.6 gas and said steam at a predetermined temperature within the range of 200.degree. to 700.degree. C., to form solid uranyl fluoride (UO.sub.2 F.sub.2) and/or uranium oxide with an O/U ratio (oxygen-to-uranium atomic ratio) of 2.7 to 3,(2) dissolving said UO.sub.2 F.sub.2 and/or uranium oxide in water or nitric acid to form an aqueous uranyl solution containing UO.sub.2 F.sub.2 and/or uranyl nitrate (UO.sub.2 (NO.sub.3).sub.2),(3) reacting said aqueous uranyl solution with ammonia to precipitate ammonium diuranate (ADU),(4) filtering said precipitate,(5) drying said precipitate,(6) calcining said dry precipitate, and(7) reducing said calcined precipitate, whereby controlling the characteristics of said UO.sub.2 powder.

Abstract: Method for treating plutonium and/or uranyl nitrate by superheating and concentrating a nitric acid starting solution, characterized by the feature that nitric acid starting solution is concentrated to form a Pu(VI)-and/or U(VI)-containing nitrate melt, is poured into a mold, is solidified by cooling down, and is transported and/or stored as a solidified solid body until further processing.

Abstract: A process for removal of H.sub.2 S from gas streams is described, the process being characterized by use of a novel iron chelate treating solution containing a specified ferric to ferrous chelate ratio, aqueous ammonia, and thiosulfate ion.

Abstract: A process for making fine, uniform metal nitride powders that can be hot pressed or sintered. A metal salt is placed in a solvent with Melamine and warmed until a metal-Melamine compound forms. The solution is cooled and the metal-Melamine precipitate is calcined at a temperature below 700.degree. C. to form the metal nitrides and to avoid formation of the metal oxide.

Abstract: The invention discloses a metal-actinide mononitride composition with dimensional stability in extended nuclear reactor operations, with a method of operation at surface temperatures in excess of 1700.degree. C. The preferred embodiment and operating method uses a mononitride of uranium and a metal selected from the group consisting of titanium or yttrium. Parameters for determination of the metal element to stabilize the fuel are disclosed.

Abstract: Hydroxymethane diphosphonic acid and alkali metal or ammonium salt of such acid are prepared. They are useful in detergent compositions and in sequestering and chelating polyvalent metals.

Abstract: Spent nuclear fuels, including actinide fuels, volatile and non-volatile fission products, are reprocessed and separated in a molten metal solvent housed in a separation vessel made of a carbon-containing material. A first catalyst, which promotes the solubility and permeability of carbon in the metal solvent, is included. By increasing the solubility and permeability of the carbon in the solvent, the rate at which actinide oxides are reduced (carbothermic reduction) is greatly increased. A second catalyst, included to increase the affinity for nitrogen in the metal solvent, is added to increase the rate at which actinide nitrides form after carbothermic reduction is complete.

Abstract: The preparation of nuclear fuels such as uranium dioxide, carbide and nitride employing the ammonium urante, (NH.sub.4).sub.2 U.sub.2 O.sub.7, as starting material usually must undergo a series of chemical and metallurgical processes at relatively high temperature and under strictly controlled working condition.A simple method for the preparation of these nuclear fuels has evolved with respect to the electrolytic amalgamation of uranium ion directly from an aqueous solution. The thereby obtained uranium amalgam maybe thermally decomposed into a fine metallic powder which reacts readily with water vapor, methane and nitrogen gas to bring forth uranium dioxide, carbide and nitride, respectively.

Abstract: A method is provided for producing a selected metal nitride utilizing a salt bath. The selected metal is introduced into the salt bath in the presence of gaseous nitrogen and at least a certain amount of a halide of the selected metal. The salt bath is maintained at a temperature above its melting point for time sufficient to form a precipitate of the desired amount of a nitride of the selected metal. In accordance with a preferred embodment, the pressure is thereafter reduced to less than atmospheric and the temperature increased above the boiling point of the salt for a time sufficient to volatilize the molten salt which is removed to leave a precipitate of the selected metal nitride. The method is particularly applicable to the production of the mononitrides of uranium, plutonium, thorium, and mixtures thereof.

Abstract: The preparation of metal and metalloid carbides, borides, nitrides silicides and sulfides by reaction in the vapor phase of the corresponding vaporous metal halide, e.g., metal chloride, with a source of carbon, boron, nitrogen, silicon or sulfur respectively in a reactor is described. Reactants can be introduced into the reactor through a reactant inlet nozzle assembly. Inhibition and often substantial elimination of product growth on exposed surfaces of such assembly is accomplished by introducing the corresponding substantially anhydrous hydrogen halide, e.g., hydrogen chloride, into the principal reactant mixing zone.

Abstract: A method for producing a beam of neutral uranium atoms is obtained by vaporizing uranium from a compound UM.sub.x heated to produce U vapor from an M boat or from some other suitable refractory container such as a tungsten boat, where M is a metal whose vapor pressure is negligible compared to that of uranium at the vaporization temperature. The compound, for example, may be the uranium-rhenium compound, URe.sub.2. An evaporation rate in excess of about 10 times that of conventional uranium beam sources is produced.

Abstract: A process for preparing actinide-nitrides from massive actinide metal which is suitable for sintering into low density fuel shapes by partially hydriding the massive metal and simultaneously dehydriding and nitriding the dehydrided portion. The process is repeated until all of the massive metal is converted to a nitride.

Abstract: An electrolytic process for making uranium from uranium oxide using Cl.sub.2 anode product from an electrolytic cell to react with UO.sub.2 to form uranium chlorides. The chlorides are used in low concentrations in a melt comprising fluorides and chlorides of potassium, sodium and barium in the electrolytic cell. The electrolysis produces Cl.sub.2 at the anode that reacts with UO.sub.2 in the feed reactor to form soluble UCl.sub.4, available for a continuous process in the electrolytic cell, rather than having insoluble UO.sub.2 fouling the cell.