In January 1958, the U.S. Atomic Energy Commission (AEC) reviewed the status of transuranium isotope production in the United States. By November of the same year, the commission decided to build the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, with a fundamental focus on isotope research and production. Since it first went critical in 1965, the in-core uses for HFIR have broadened to include materials research, fuels research, and fusion energy research, in addition to isotope production and research for medical, nuclear, detector and security purposes.