Mixed-oxide (MOX) fuel

A type of nuclear reactor fuel that contains plutonium oxide mixed with either natural or depleted uranium oxide, in ceramic pellet form. This differs from conventional nuclear fuel, which is made of uranium oxide. The U.S. Department of Energy program to produce an MOX fuel under an agreement with Russia was canceled in 2018. The NRC terminated the facility’s construction authorization in February 2019. For further detail, see the Backgrounder on Mixed Oxide Fuel and Frequently Asked Questions About Mixed Oxide Fuel.