High-performance reactor-based research facilities have been an essential part of the U.S. scientific and technological enterprise since the mid-1960s. These facilities contribute broadly to our national security, our fundamental and applied science knowledge base, our development of cutting-edge medical treatments, and our technological and industrial competitiveness. The flagship U.S. reactor facility is the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). This reactor is stewarded by the U.S. Department of Energy (DOE) under the auspices of Basic Energy of Sciences in the Office of Science.