This chemical compound - with the formula UF6 - contains 1 atom of uranium and 6 atoms of fluorine. In its solid form, its a white crystalline substance. This uranium compound is used during the uranium enrichment process.
Uranium hexafluoride is a solid at room temperature but forms a gas when heated. In gaseous form, the concentration of the fissionable isotope 235U, can be increased from the natural level of 0.711% to nuclear fuel levels of 3.0–5.0% by either a diffusion or centrifuge process.
Uranium hexafluoride is used widely in uranium processing as it can conveniently be used as a gas for processing, but can also be transported and stored as a solid or liquid without the use of extreme pressures or temperatures.
UF6 is used primarily in the gaseous diffusion and gas centrifuge processes that are used to enrich uranium. In gaseous diffusion, mined uranium ore is sent to a plant that produces uranium oxide, more commonly known as "yellowcake".
Uranium hexafluoride is not flammable or explosive, however it does react with water. When exposed to water, uranium hexafluoride undergoes rapid conversion into uranyl fluoride and hydrogen fluoride. If it is exposed to excess levels of water, the hydrogen fluoride then forms hydrofluoric acid, which poses a burn risk.
Uranium hexafluoride is transported worldwide in special transport containers in a solid form. During transport, the pressure inside these containers is maintained below atmosoheric pressure to ensure the uranium remains in solid form.