Search results
Results from the WOW.Com Content Network
Uranium dioxide is minimally soluable in water, but after oxidation it can be converted to uranium trioxide or another uranium(VI) compound which is much more soluble. Uranium dioxide (UO 2 ) can be oxidised to an oxygen rich hyperstoichiometric oxide (UO 2+x ) which can be further oxidised to U 4 O 9 , U 3 O 7 , U 3 O 8 and UO 3 .2H 2 O.
In addition, because of the absence of oxygen in this fuel (during the course of irradiation, excess gas pressure can build from the formation of O 2 or other gases) as well as the ability to complement a ceramic coating (a ceramic-ceramic interface has structural and chemical advantages), uranium carbide could be the ideal fuel candidate for ...
According to the patent application [5] the reactor design has some notable characteristics, that sets it apart from other reactor designs. It uses uranium hydride (UH 3) "low-enriched" to 5% uranium-235—the remainder is uranium-238—as the nuclear fuel, rather than the usual metallic uranium or uranium dioxide that composes the fuel rods of contemporary light-water reactors.
Uranium dioxide or uranium(IV) oxide (UO 2), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used as MOX fuel.
The less-moderated neutrons are relatively more likely to be captured by uranium-238 and less likely to fission uranium-235, so light-water reactors require enriched uranium to operate. There are also proposals to use the compound formed by the chemical reaction of metallic uranium and hydrogen ( uranium hydride —UH 3 ) as a combination fuel ...
The resulting uranium hydride is pyrophoric; if the metal (e.g. a damaged fuel rod) is exposed to air afterwards, excessive heat may be generated and the bulk uranium metal itself can ignite. [11] Hydride-contaminated uranium can be passivated by exposure to a gaseous mixture of 98% helium with 2% oxygen . [ 12 ]
All uranium chlorides react with water and air. Bromides and iodides of uranium are formed by direct reaction of, respectively, bromine and iodine with uranium or by adding UH 3 to those element's acids. [6] Known examples include: UBr 3, UBr 4, UI 3, and UI 4. UI 5 has never been prepared. Uranium oxyhalides are water-soluble and include UO 2 ...
Thermal decomposition of concrete produces water vapor and carbon dioxide, which may further react with the metals in the melt, oxidizing the metals, and reducing the gases to hydrogen and carbon monoxide. The decomposition of the concrete and volatilization of its alkali components is an endothermic process.