Idaho National Laboratory Cracks the Code on Molten Salt Fuel Production

Researchers at Idaho National Laboratory (INL) have successfully developed an efficient method to produce fuel for the world's first fast-spectrum, salt-fueled reactor test. This advancement is pivotal for the Molten Chloride Reactor Experiment (MCRE), aiming to explore a novel class of reactors.

In 2020, INL initiated the design of a fuel salt synthesis process to create molten chloride fuel salt. The objective was to produce 18 kilograms of fuel salt per batch, achieving a 90% conversion rate of uranium metal feedstock into uranium chloride fuel salt—a target previously unreached.

Initially, the team managed to convert up to 80% of uranium metal, yielding 10 kilograms of fuel salt per batch. A significant breakthrough occurred last summer when they introduced a new step, enhancing uranium utilization to 95% and producing 18 kilograms of fuel salt. However, this process required approximately 200 hours, rendering it unsustainable for large-scale production.

Collaborating with experts from Southern Company and TerraPower, the team designed experiments to reduce production time. They can now sustainably produce 18 kilograms of fuel salt in just 8 hours, with plans to further decrease this time to 6 hours.

This efficient fuel production process is crucial for the MCRE, a 200-kilowatt-thermal reactor designed to operate at high temperatures using molten chloride salts as both fuel and coolant. The MCRE will provide essential data to validate the design and licensing of larger-scale molten chloride reactors, potentially leading to more efficient and cost-effective energy production.

The successful development of this fuel production method marks a significant step toward demonstrating the viability of molten chloride reactors, offering a promising avenue for advanced nuclear energy systems.