Abstract: The method described herein may be characterized as reacting uranium dioxide with carbon to produce uranium carbide, and, reacting the uranium carbide with a silane, a silicon halide, a siloxane, or combinations thereof, and excess hydrogen to produce uranium silicide.

Abstract: A metal carbide ceramic fiber having improved mechanical properties and characteristics and improved processes and chemical routes for manufacturing metal carbide ceramic fiber. Metal carbide ceramic fibers may be formed via reaction bonding of a metal-based material (e.g. boron) with the inherent carbon of a carrier medium. One embodiment includes a method of making a metal carbide ceramic fiber using VSSP to produce high yield boron carbide fiber. Embodiments of the improved method allow high volume production of high density boron carbide fiber. The chemical routes may include a direct production of boron carbide fiber from boron carbide powder (B4C) and precursor (e.g. rayon fiber) having a carbon component to form a B4C/rayon fiber that may be processed at high temperature to form boron carbide fiber, and that may be subsequently undergo a hot isostatic pressing to improve fiber purity. Another route may include a carbothermal method comprising combining boron powder (B) with a precursor (e.g.

Abstract: A method for measuring intensity distribution of light is disclosed. The method includes the steps of manufacturing a superaligned carbon nanotube array arranged on a substrate; irradiating a top surface of the superaligned carbon nanotube array with a light source and changing the morphology of the top surface of the superaligned carbon nanotube array; and obtaining an intensity distribution of the light source by analyzing the morphology of the top surface of the superaligned carbon nanotube array.

Abstract: An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound (“PYRUC”) shielding material is preferably formed by heat and/or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

Abstract: The invention relates to a silicon carbide or metal carbide foam to be used as a catalyst or catalyst support for the chemical or petrochemical industry or for silencers, as well as the process for producing the same. The foam is in the form of a three-dimensional network of interconnected cages, whose edge length is between 50 and 500 micrometres, whose density is between 0.03 and 0.1 g/cm3 and whose BET surface is between 20 and 100 m2/g. The carbide foam contains no more than 0.1% by weight residual metal and the size of the carbide crystallites is between 40 and 400 Angstroms. The production process consists of starting with a carbon foam, increasing its specific surface by an activation treatment using carbon dioxide and then contacting the thus activated foam with a volatile compound of the metal, whose carbide it is wished to obtain.

Abstract: A method of preparing active, sinterable, finely-divided plutonium oxide (PuO.sub.2) powder from plutonium metal is disclosed. The process yields plutonium fissile material which can be easily blended to form a uniformly homogeneous powder for the fabrication of high-quality light water reactor ceramic fuel pellets. Such homogeneous fuels are required to prevent hot spots from developing in a reactor using the fuel.

Abstract: A method for producing UO.sub.2 or (U/Pu)O.sub.2 powder includes obtaining ammonium uranyl carbonate or ammonium uranyl plutonyl carbonate by treating a starting oxide selected from the group consisting of uranium oxide, plutonium oxide and uranium plutonium mixed oxide, with at least one solution selected from the group consisting of aqueous ammonium carbonate solution and aqueous ammonium hydrogen carbonate solution. The ammonium uranyl carbonate or ammonium uranyl plutonyl carbonate is then heated and in particular calcined.

Abstract: Matter is floated to the surface of a liquid by bonding ions to the surface of the matter to give the matter a charge, and forming a froth with the aid of a frothing agent having groups of opposite charge to the ions so that the frothing agent bonds to the matter and is carried in the froth to the surface of the liquid. By removing the froth the matter can be separated from any inert matter present in the liquid. The oxidation state of the surface of the matter may be changed before bonding takes place with the ions to one which facilitates that bonding. The matter can be particulate or dissolved ions. For example, uranium dioxide particles are oxidized with hydrogen peroxide, sodium carbonate added to produce a negatively charged uranyl carbonate complex and a froth formed with the aid of cetyl trimethylammonium bromide. Cationic groups in the latter bond to the uranyl carbonate complex causing the uranyl carbonate complex to be concentrated in the froth at the surface of the liquid.

Abstract: Preparation of metal carbides, nitrides, borides, silicides and phosphides, also metal alloys and pure metals, by providing a precursor in which there are organic ligands bonded to the metal or metals, such precursor having the element X also bonded directly or indirectly to the metal or metals, the ligand-metal bonding being weaker than the X-metal bonding whereby on pyrolysis the product M.sub.a X.sub.b results in which M represents the metal or metals, X represents C, N, B, Si, P and a and b represent the atomic proportions of M and X. The subscript b may be zero if an alloy or pure metal is to be prepared. The product M.sub.a x.sub.b can be prepared by relatively low temperature pyrolysis and the precursor can be used as a solution or a low melting solid. This enables one to apply a surface coating or to shape the precursor into a fiber, rod or other shape and to pyrolyze the coating or shaped article. M is a transition, lanthanide or actinide metal or tin.

Abstract: Transition metal carbides in which the carbon is in excess and is covalently bound to the metal are produced by pyrolyzing transition metal amides that have two or more metal atomos, such as hexakis(dimethylamido) ditungsten or dimolybdenum.

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: 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: Flexible metal carbide fabrics are produced by a process that involves the steps of:(a) impregnating a preformed organic polymeric fabric with a solution of a metal compound;(b) heating the impregnated fabric to evolve volatile decomposition products and to leave a carbonaceous relic containing the metal in finely dispersed form; and(c) further heating the relic to 1000.degree.-2400.degree. C. in a non-oxidizing atmosphere to form the metal carbide. Boron carbide and silicon carbide fabrics produced by this process are attractive for high temperature structural applications.

Abstract: Class III-B metal ores such as Thorium and Uranium oxides are reduced to the powdered metal state by mixing them with a hydroxide such as Sodium Hydroxide (NaOH), or others of the Classes I-A and II-A metal series, and sugar or starch, then heating the mixture until hydrocarbon fuel is produced and burns utilizing the oxygen of the ores for such combustion, then boiling the residue in water, flushing and rinsing it in same, further cleansing in hydrocarbon or alcohol solutions, again flushing and rinsing in water, drying, and screening the residue to metal powder.

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: Pure monocarbides, or pure mononitrides or carbonitrides of metals are prepared by first forming a mixture of carbon with an oxalate of the metals and thermally decomposing the metal oxalate in the presence of the carbon by a stream of hydrogen. The hydrogen is removed and monocarbides are then formed by heating the decomposition products in vacuo to carbothermally reduce them. Mononitrides and carbonitrides can be formed by replacing the hydrogen with nitrogen and heating the decomposition products in the nitrogen.

Abstract: Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen cabonate or an NH.sub.4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol.