Uranium dioxide, or UO2, is a compound formed from uranium and oxygen. It is a black, solid material that is primarily used as fuel in nuclear reactors. The compound is known for its high melting point and good thermal conductivity, making it suitable for sustaining nuclear fission reactions. In the nuclear industry, uranium dioxide is often processed into small pellets, which are then stacked into fuel rods. These rods are placed in the core of a nuclear reactor, where they undergo fission to produce energy. The efficient use of UO2 is crucial for generating electricity in many countries around the world.