Inside the first fast-spectrum molten chloride reactor fuel ever produced

Idaho National Laboratory (INL) has successfully produced the first batch of fuel for the United States’ experimental Molten Chloride Reactor Experiment (MCRE), marking a significant milestone toward realizing fast-spectrum molten chloride reactors. Unlike conventional nuclear reactors that use solid fuel rods and moderators to slow neutrons, the MCRE employs a liquid nuclear-enriched chloride salt fuel and operates with fast neutrons, enabling higher energy density, reduced waste, and more compact reactor designs. This approach also allows the reactor to reach higher temperatures and supports industrial applications such as hydrogen production and heavy manufacturing, while maintaining inherent safety features like passive cooling and meltdown resistance. The MCRE is unique in its use of chloride salts instead of the more common fluoride salts, which contributes to its ability to operate as a fast-spectrum reactor. The project, a collaboration between INL, Southern Company, TerraPower, CORE POWER, and the U.S. Department of Energy, aims to develop a versatile, safer, and cleaner nuclear power source that