Oak Ridge National Laboratory (ORNL) is the U.S. Department of Energy's largest science and energy laboratory — founded in 1943 as Clinton Laboratories for the Manhattan Project, sited in Oak Ridge, Tennessee, and operated for the DOE by UT-Battelle with a staff of more than 7,000.
ORNL's Fusion Energy Division is organized in two sections: Burning Plasma Foundations, which develops the physics basis for long-pulse operation and power exhaust, and Fusion Nuclear Science, Technology and Engineering, which builds the subsystems a power plant needs — fuel cycles, heating systems, remote maintenance. The laboratory is the U.S. center of gravity for fusion materials and neutronics. Specimens of 📝tungsten and 📝RAFM steel are irradiated in the High Flux Isotope Reactor at controlled temperatures from 300 °C to 1200 °C, then disassembled and mechanically tested in shielded hot cells — the closest available stand-in for the 📝neutron damage a D-T power plant inflicts. The division is also building MPEX, the Material Plasma Exposure eXperiment, a linear device intended to expose 📝plasma-facing components to reactor-like steady particle fluxes.
ORNL hosts the US ITER Project Office, which manages the American in-kind contribution to 📝ITER — the 📝central solenoid, 📝toroidal field coil conductor, 📝pellet injection fueling, 📝disruption mitigation, tokamak exhaust processing and diagnostics — with Princeton Plasma Physics Laboratory and Savannah River National Laboratory in support. That roughly 9 percent funding share buys the United States full access to ITER's technology and data. With Princeton, ORNL also jointly leads 📝INFUSE, the DOE program that opens laboratory capability to private 📝fusion companies.