Since the latest episode of the Israel-Iran conflict began on June 13, uranium centrifuges have drawn global attention. According to Israel and the U.S., these Iranian nuclear facilities held several hundred, possibly thousands, of uranium centrifuges. These machines play a crucial role in Iran’s nuclear efforts—and in any nuclear program aimed at weapons—by enriching uranium to 90%. Uranium-235 Is the Real Protagonist of this StoryTo understand the role of uranium centrifuges, it’s important to examine two isotopes of this heavy, radioactive metal. Centrifuges can only separate gases, so the uranium must be converted into uranium hexafluoride (UF6), a gas.