The Molten Chloride Reactor Experiment aims to achieve first criticality in 2027, with the US Department of Energy approving cost-shared funding under its Advanced Reactor Demonstration Program.
The funding for an accelerated final stage is intended to support work by utility Southern Company, Idaho National Laboratory and maritime nuclear specialist Core Power to "advance scientific understanding of molten salt reactor technology and inform future reactor development".
The Molten Chloride Reactor Experiment is expected to generate data on the behaviour of the fuel, reactor operation and performance "providing the scientific and engineering foundation needed to support future reactor design, licensing pathways and commercial deployment".
Jess Gehin, associate laboratory director for Nuclear Science and Technology at Idaho National Laboratory, said: "MCRE (The Molten Chloride Reactor Experiment) will be the world's first fast-spectrum molten chloride reactor to achieve criticality. It will provide direct measurements of how this novel reactor behaves during sustained fission, data that until now, has come from models alone. Enhancing those models with real-world operating evidence will reduce uncertainty for future reactor designers and regulators."
Mark Berry, Southern Company senior vice president of research, environment and sustainability, said: "Public-private partnerships play an essential role in advancing energy technologies from concept to demonstration. Through collaboration among DOE, Idaho National Laboratory and industry partners, MCRE will help expand knowledge of molten salt reactor technology and help reduce technical uncertainty for future developers."
Mikal Bøe, CEO of Core Power, said: "Core Power's role in this partnership is to help translate advanced reactor technology into deployable industrial systems and unique delivery mechanisms needed to realise the potential of this technology. Merging the pathway of novel nuclear fuel cycle development that MCRE represents with Core Power's pathway of maritime nuclear development, creates unique opportunities to deliver an ultimately sustainable nuclear fuel solution to new markets around the world. One such market is a sustainable future of civil maritime nuclear propulsion of large commercial ships, where an enduring, zero-emission power source can transform the way global trade is transported at sea."
The Molten Chloride Reactor Experiment uses liquid salt as the fuel and the coolant, allowing for high operating temperatures to efficiently produce heat or electricity. It will need 72 to 75 batches of fuel salt to enable it to go critical - giving Idaho National Laboratory its largest fuel production challenge in 30 years, according to the DOE Office of Nuclear Energy. The fuel salt production process began in 2020, but early attempts yielded far below the goal of 90% conversion of uranium metal into uranium chloride and production of 18 kg of fuel salt per batch. But a breakthrough in 2024 - when the team developed a new step to improve uranium utilisation - eventually led to the achievement of 95% conversion and full-batch production. They have since demonstrated they can produce a batch in as little as one day, according to INL.