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 and is corrosive to most metals. It reacts mildly with
aluminium, forming a thin surface layer of
AlF3 that resists further reaction.