The U.S. Department of Energy is preparing to restart the Transient Reactor Test Facility at the Idaho National Laboratory, more commonly known as TREAT. The pulsed reactor, built in 1959, has not operated since 1994. It is expected that the facility will become operational in 2018.

The TREAT reactor is one of the few research facilities in the United States that use HEU fuel. The reactor core contains about 20 kg of U3O8 in graphite matrix with uranium enriched to 93.1% U-235. Department of Energy has studied the feasibility of converting TREAT to LEU fuel, but it is not clear whether the conversion will be completed by 2018.