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The metal uranium forms several oxides: Uranium dioxide or uranium(IV) oxide (UO 2, the mineral uraninite or pitchblende) Diuranium pentoxide or uranium(V) oxide (U 2 O 5) Uranium trioxide or uranium(VI) oxide (UO 3) Triuranium octoxide (U 3 O 8), the most stable uranium oxide; yellowcake typically contains 70 to 90 percent triuranium octoxide)
The most common forms of uranium oxide are triuranium octoxide (U 3 O 8) and UO 2. [3] Both oxide forms are solids that have low solubility in water and are relatively stable over a wide range of environmental conditions. Triuranium octoxide is (depending on conditions) the most stable compound of uranium and is the form most commonly found in ...
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.
For natural uranium fuel, fissile component starts at 0.7% 235 U concentration in natural uranium. At discharge, total fissile component is still 0.5% (0.2% 235 U, 0.3% fissile 239 Pu, 241 Pu ). Fuel is discharged not because fissile material is fully used-up, but because the neutron-absorbing fission products have built up and the fuel becomes ...
The use of pitchblende, uranium in its natural oxide form, dates back to at least the year 79 AD, when it was used in the Roman Empire to add a yellow color to ceramic glazes. [12] Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Bay of Naples, Italy, by R. T. Gunther of the University of Oxford in 1912. [29]
A collection of uranium glassware. ADU is an intermediate in the production of uranium oxides to be used as nuclear fuel; it is converted directly into an oxide by heating. β-UO 3 is produced at about 350 °C and U 3 O 8 is obtained at higher temperatures. When the alkali used is sodium hydroxide, so-called sodium diuranate, SDU, is produced.
The second is a medium to large (500–1,500 MWe) sodium-cooled reactor with mixed uranium-plutonium oxide fuel, supported by a fuel cycle based upon advanced aqueous processing at a central location serving multiple reactors. The outlet temperature is approximately 510–550 degrees C for both.
Mixed oxide, or MOX fuel, is a blend of plutonium and natural or depleted uranium which behaves similarly (though not identically) to the enriched uranium feed for which most nuclear reactors were designed. MOX fuel is an alternative to low enriched uranium (LEU) fuel used in the light water reactors which predominate nuclear power generation.