Uranyl fluoride a compound of uranium

Uranium

Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

, is an intermediate in the conversion of uranium hexafluoride

Uranium hexafluoride

Uranium hexafluoride , referred to as "hex" in the nuclear industry, is a compound used in the uranium enrichment process that produces fuel for nuclear reactors and nuclear weapons. It forms solid grey crystals at standard temperature and pressure , is highly toxic, reacts violently with water...

 UF₆ to an uranium oxide

Uranium oxide

Uranium oxide is an oxide of the element uranium.The metal uranium forms several oxides:* Uranium dioxide or uranium oxide * Uranium trioxide or uranium oxide...

 or metal form and is a direct product of the reaction of UF₆ with moisture in the air. It is very soluble in water. Uranyl fluoride also is hygroscopic and changes in color from brilliant orange to yellow after reacting with water. Uranyl fluoride is reported to be stable in air to 300 °C, above which slow decomposition to U₃O₈ occurs. When heated to decomposition, UO₂F₂ emits toxic fluoride fumes.

In accidental releases of UF₆, UO₂F₂, as a solid particulate compound, may deposit on the ground. The overall chemical reaction of this event can be represented as:

UF₆ + 2 H₂O → UO₂F₂ + 4 HF.

These reactions can take place whether the uranium hexafluoride is a solid or a gas, but will take place almost instantaneously when the UF₆ is in a gaseous state. The resulting hydrofluoric acid

Hydrofluoric acid

Hydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....

 and the presence of additional water results in formation of solids (primarily Hydrofluoric adduct

Adduct

An adduct is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species...

s of hydrated uranyl fluoride (UO₂F₂−nH₂O).

Toxicology

Chemical hazards are far more significant than radioactive hazards, though there is a radioactivity concern if prepared with enriched uranium. Material is corrosive, and harmful by inhalation, ingestion or skin absorption. Ingestion or inhalation may be fatal. Effects of exposure may be delayed.