In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

A method for preparing a powder comprising an intimate mixture of U.sub.3O.sub.8 particles and PuO.sub.2 particles and which may further comprise particles of ThO.sub.2 or NpO.sub.2. The method comprises: preparing, via oxalic precipitations, an aqueous suspension S.sub.1 of particles of uranium(IV) oxalate and an aqueous suspension S.sub.2 of particles of plutonium(IV) oxalate; mixing the aqueous suspension S.sub.1 with the aqueous suspension S.sub.2 to obtain an aqueous suspension S.sub.1+2, separating the aqueous suspension S.sub.1+2 into an aqueous phase and a solid phase comprising the particles of uranium(IV) oxalate and the particles of plutonium(IV) oxalate; and calcining the solid phase to convert (1) the particles of uranium(IV) oxalate to particles of triuranium octoxide and (2) the particles of plutonium(IV) oxalate to particles of plutonium(IV) dioxide, whereby the powder is obtained.

A method for preparing a powder comprising an intimate mixture of U.sub.3O.sub.8 particles and PuO.sub.2 particles and which may further comprise particles of ThO.sub.2 or NpO.sub.2. The method comprises: preparing, via oxalic precipitations, an aqueous suspension S.sub.1 of particles of uranium(IV) oxalate and an aqueous suspension S.sub.2 of particles of plutonium(IV) oxalate; mixing the aqueous suspension S.sub.1 with the aqueous suspension S.sub.2 to obtain an aqueous suspension S.sub.1+2, separating the aqueous suspension S.sub.1+2 into an aqueous phase and a solid phase comprising the particles of uranium(IV) oxalate and the particles of plutonium(IV) oxalate; and calcining the solid phase to convert (1) the particles of uranium(IV) oxalate to particles of triuranium octoxide and (2) the particles of plutonium(IV) oxalate to particles of plutonium(IV) dioxide, whereby the powder is obtained.

A method for purifying uranium includes forming primary uranyl peroxide precipitates (UO.sub.2O.sub.2.4H.sub.2O). Forming the primary uranyl peroxide precipitates includes obtaining impure uranium dissolved in an acidic solution, evaporating the acidic solution to increase uranium concentration and to form a concentrated solution, mixing a hydrogen peroxide (H.sub.2O.sub.2) solution with the concentrated solution in a first container, and forming uranyl peroxide precipitates in the first container. The method includes collecting the uranyl peroxide precipitates and washing and drying the uranyl peroxide precipitates. The method also includes converting the washed and dried uranyl peroxide precipitates into triuranium octoxide (U.sub.3O.sub.8).

Metal oxide gel particles, may be prepared with a desired particle size, by preparing a low-temperature aqueous metal nitrate solution containing hexamethylene tetramine as a feed solution; and causing the feed solution to flow through a first tube and exit the first tube as a first stream at a first flow rate, so as to contact a high-temperature nonaqueous drive fluid. The drive fluid flows through a second tube at a second flow rate. Shear between the first stream and the drive fluid breaks the first stream into particles of the metal nitrate solution, and decomposition of hexamethylene tetramine converts metal nitrate solution particles into metal oxide gel particles. A metal oxide gel particle size is measured optically, using a sensor device directed at a flow of metal oxide gel particles within the stream of drive fluid. The sensor device measures transmission of light absorbed by either the metal oxide gel particles or the drive fluid, so that transmission of light through the drive fluid changes for a period of time as a metal oxide gel particle passes the optical sensor. If a measured particle size is not about equal to a desired particle size, the particle size may be corrected by adjusting a ratio of the first flow rate to a total flow rate, where the total flow rate is the sum of the first and second flow rates.

Metal oxide gel particles, may be prepared with a desired particle size, by preparing a low-temperature aqueous metal nitrate solution containing hexamethylene tetramine as a feed solution; and causing the feed solution to flow through a first tube and exit the first tube as a first stream at a first flow rate, so as to contact a high-temperature nonaqueous drive fluid. The drive fluid flows through a second tube at a second flow rate. Shear between the first stream and the drive fluid breaks the first stream into particles of the metal nitrate solution, and decomposition of hexamethylene tetramine converts metal nitrate solution particles into metal oxide gel particles. A metal oxide gel particle size is measured optically, using a sensor device directed at a flow of metal oxide gel particles within the stream of drive fluid. The sensor device measures transmission of light absorbed by either the metal oxide gel particles or the drive fluid, so that transmission of light through the drive fluid changes for a period of time as a metal oxide gel particle passes the optical sensor. If a measured particle size is not about equal to a desired particle size, the particle size may be corrected by adjusting a ratio of the first flow rate to a total flow rate, where the total flow rate is the sum of the first and second flow rates.

The invention is related to nuclear technologies, in particular, to the technology of producing nuclear oxide fuel for fuel elements, this oxide fuel can be used for manufacturing palletized nuclear fuel from uranium dioxide to be consumed by NPPs. The essence of the invention: this method of producing palletized nuclear fuel from uranium dioxide involves preparation of uranium dioxide moulding powder with/without uranium oxide, at this point powdered uranium dioxide is used as a raw material for preparation of moulding powder. Powdered uranium dioxide should be in the following proportion: O/U=2.370.04, it is obtained using a renowned methodby air heating of powdered uranium dioxide (ceramic grade) with the following proportion O/U=2.012.15. The technical result of the invention is increased mechanical strength of sintered pellets and a larger grain size of sintered pellets.

Electrical devices operating in a range of 273 C. to 100 C. are disclosed. The devices include an insulating substrate. A UO.sub.2+x crystal or oriented crystal UO.sub.2+x film is on a first portion of the substrate. The UO.sub.2+x crystal or film originates and hosts a non-equilibrium polaronic quantum phase-condensate. A first lead on a second portion of the substrate is in electrical contact with the UO.sub.2+x crystal or film. A second lead on a third portion of the surface is in electrical contact with the UO.sub.2+x crystal or film. The leads are isolated from each other. A UO.sub.2+x excitation source is in operable communication with the UO.sub.2+X crystal or film. The source is configured to polarize a region of the crystal or film thereby activating the non-equilibrium quantum phase-condensate. One source state causes the UO.sub.2+X crystal or film to be conducting. Another source state causes the UO.sub.2+x crystal or film to be non-conductive.

A method loading powder into a mold can include immersing the mold comprising one or more microchannels into a suspension comprising the powder and a surfactant suspended in a dispersant, wherein the powder comprises particles having an average particle size of less than 100 m, wherein the mold is substantially entirely covered by the suspension; heating the suspension having the mold immersed therein under a temperature condition suitable to lower the stability of the particles of the powder in the suspension such that the particles settle out of solution and into the one or more microchannels; and applying an ultrasonic wave to the heated suspension to further settle the particles of the powder into the one or more microchannels thereby filling the one or more microchannels of the mold with the powder.

A method loading powder into a mold can include immersing the mold comprising one or more microchannels into a suspension comprising the powder and a surfactant suspended in a dispersant, wherein the powder comprises particles having an average particle size of less than 100 m, wherein the mold is substantially entirely covered by the suspension; heating the suspension having the mold immersed therein under a temperature condition suitable to lower the stability of the particles of the powder in the suspension such that the particles settle out of solution and into the one or more microchannels; and applying an ultrasonic wave to the heated suspension to further settle the particles of the powder into the one or more microchannels thereby filling the one or more microchannels of the mold with the powder.