Contract signed for pilot UK integral molten salt reactor fuel plant

The agreement builds on a contract signed in August 2023 for the planning and initial design of IMSR fuel supply, leveraging the established deconversion and fuel manufacturing infrastructure at Westinghouse’s Springfields nuclear fuel manufacturing site in Preston in the UK. It has been expanded in scope to include a "wide range of commercial-scale fuel services" such as deconversion, fabrication, packaging and transportation. "Upon completion of the pilot plant, the facility will be positioned to scale to commercial fuel production for a future fleet of IMSR Plants," Terrestrial Energy said.

Terrestrial Energy's Integrated Molten Salt Reactor (IMSR) is a 4th generation reactor that uses molten salt as both fuel and coolant, with integrated components, which can supply heat directly to industrial facilities or use it to generate electrical power. It does this using conventional nuclear reactor fuel - standard assay low-enriched uranium, enriched to under 5% uranium-235. The use of this fuel - which the company refers to as SALEU - aligns with Springfields' "nearly 80-year legacy as a global leader in the supply of SALEU as uranium oxide fuel to commercial nuclear power reactors", the company said.

"Terrestrial Energy’s use of SALEU, the only commercially available reactor fuel on the market today, for IMSR plant operation shields the company from substantial supply challenges associated with the use of High-Assay Low-Enriched Uranium fuel (HALEU), which have been exacerbated by geopolitical tensions and the current lack of commercial-scale supply in the US market," it added. "SALEU supply chains are supported by well-established international transport protocols and decades of regulatory acceptance, positioning Terrestrial Energy to pursue a practical and accelerated pathway to early commercial IMSR plant deployment."

The pilot plant design features a re-optimised chemical process to supply uranium tetrafluoride - UF4 - which has been deconverted from uranium hexafluoride (UF6) at 5% enrichment: the current industry standard is the deconversion of UF6 at 5% enrichment, supplied from enrichment plants, to uranium oxide fuel. Optimising the process to deconvert to UF4 with the pilot plant design will enable the large-scale fuel supply required for IMSR fleet deployment by leveraging Springfields' existing commercial scale infrastructure, the company said.

Terrestrial Energy CEO Simon Irish said the expanded partnership with Westinghouse at Springfields is a "strategic milestone" in Terrestrial Energy's Western supply chain strategy as it commercialises its reactor technology. "With our SALEU fuel choice, we can maximise the use of existing nuclear industrial infrastructure at the Springfields site for capital efficiency. This collaboration enhances both our capital efficiency and scalability as we seek to meet the rapidly growing demand for clean, reliable, and flexible energy supply," he said.

Tarik Choho, Westinghouse President of Nuclear Fuel, said the company has been working with Terrestrial Energy on this "transformative initiative" for more than four years. "This partnership brings together complementary strengths and opportunities, accelerating innovation and delivering important impacts to our industry," he said.

Construction of the new plant is set to begin in 2026.