A uranium oxide fuel pellet having an inner region and an outer rim region about the inner region, and that the fuel pellet is cylindrical and the inner region and outer rim region are coaxial cylindrical regions. The outer rim region has an excess of oxygen in comparison to the inner region , wherein high burnup structure (HBS) formation will be suppressed or delayed. Preferably, the excess oxygen is obtained by a chemical treatment by immersing the pellet in hydrogen peroxide (H.sub.2O.sub.2) or potassium permanganate (KMnO.sub.4) in solution.

A uranium oxide fuel pellet having an inner region and an outer rim region about the inner region, and that the fuel pellet is cylindrical and the inner region and outer rim region are coaxial cylindrical regions. The outer rim region has an excess of oxygen in comparison to the inner region , wherein high burnup structure (HBS) formation will be suppressed or delayed. Preferably, the excess oxygen is obtained by a chemical treatment by immersing the pellet in hydrogen peroxide (H.sub.2O.sub.2) or potassium permanganate (KMnO.sub.4) in solution.

Electrical devices 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.

Electrical devices 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.

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.

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.

The application discloses a preparation method of monocrystal uranium dioxide nuclear fuel pellets, comprising: granulating and pelleting UO.sub.2 powder to obtain UO.sub.2 pellets; then coating surfaces of the UO.sub.2 pellets with monocrystal growth additive micro powder to form core-shell structure particles; and activated-sintering the core-shell structure particles at high temperature, liquefying the monocrystal growth additive on the surface of the core-shell structure particle at high temperature and then diffusing into UO.sub.2 pellets, dissolving the UO.sub.3 in the liquid monocrystal growth additive, and recrystallizing the UO.sub.2 to form the monocrystal UO.sub.2 nuclear fuel pellets.

The application discloses a preparation method of monocrystal uranium dioxide nuclear fuel pellets, comprising: granulating and pelleting UO.sub.2 powder to obtain UO.sub.2 pellets; then coating surfaces of the UO.sub.2 pellets with monocrystal growth additive micro powder to form core-shell structure particles; and activated-sintering the core-shell structure particles at high temperature, liquefying the monocrystal growth additive on the surface of the core-shell structure particle at high temperature and then diffusing into UO.sub.2 pellets, dissolving the UO.sub.3 in the liquid monocrystal growth additive, and recrystallizing the UO.sub.2 to form the monocrystal UO.sub.2 nuclear fuel pellets.

Embodiments of the disclosure relate to a treatment method and a treatment apparatus for a UF.sub.6 heel, using a gas phase reaction. A specific treatment method includes (1) vaporizing the UF.sub.6 heel, (2) manufacturing solid phase UO.sub.2F.sub.2 by using UF.sub.6 gas vaporized at step (1), (3) separating the solid phase UO.sub.2F.sub.2 and by-product gas from each other, and (4) separating hydrogen fluoride from the by-product gas. According to the disclosure, stabilization of a reconversion process and the quality of UO.sub.2 powder may be improved by manufacturing the solid phase UO.sub.2F.sub.2, which is an intermediate of the UO.sub.2 powder, through the UF.sub.6 heel treatment, and the high cost of radioactive waste disposal is reduced by minimizing the UF.sub.6 heel to be less than 0.5 kg.

Embodiments of the disclosure relate to a treatment method and a treatment apparatus for a UF.sub.6 heel, using a gas phase reaction. A specific treatment method includes (1) vaporizing the UF.sub.6 heel, (2) manufacturing solid phase UO.sub.2F.sub.2 by using UF.sub.6 gas vaporized at step (1), (3) separating the solid phase UO.sub.2F.sub.2 and by-product gas from each other, and (4) separating hydrogen fluoride from the by-product gas. According to the disclosure, stabilization of a reconversion process and the quality of UO.sub.2 powder may be improved by manufacturing the solid phase UO.sub.2F.sub.2, which is an intermediate of the UO.sub.2 powder, through the UF.sub.6 heel treatment, and the high cost of radioactive waste disposal is reduced by minimizing the UF.sub.6 heel to be less than 0.5 kg.