British advanced nuclear technology developer MoltexFLEX has been awarded a Government grant worth £1.3 million (US$1.65 million) via the Nuclear Fuel Fund (NFF) to accelerate the development of fuel for its innovative FLEX reactor.

The NFF grant will provide funding for MoltexFLEX to develop detailed technical plans for commercial-scale delivery of its low-enriched uranium fuel salt. In turn, this will help solidify the UK’s position as a leader in the global nuclear sector.

MoltexFLEX is a UK business, developing its low-cost and passively safe FLEX reactor and GridReserve energy storage technology. Together, these innovations generate flexible energy which complements intermittent renewables such as wind and solar. Headquartered in Warrington, the business has ambitious plans to expand its team to several hundred employees within a few years.

“This award represents an important signal of support from Government for advanced modular reactors in the UK, and helps MoltexFLEX make significant progress in commercialising the fuel salt manufacturing route for the FLEX reactor,” said MoltexFLEX CEO David Landon. “We are delighted to receive this grant, which will help make advanced nuclear technology a reality.”

MoltexFLEX’s ability to create a domestic supply chain for the fuel will guarantee the UK a decades-long stream of economic activity. In the case of the low-cost small modular FLEX reactor, which is intended to be mass produced, fuel accounts for approximately 50% of the capital cost.

“Government support for British technology exporters like Rolls-Royce SMR and MoltexFLEX will generate new high-quality, long-term jobs and careers within the nuclear industry in the UK,” said Jez Stewart, National Secretary of the trade union Prospect.

The NFF award is further evidence of the growing external validation of MoltexFLEX’s progression. Having won funding from the Henry Royce Institute in January 2023, the company was also one of this year’s winners of the Green Builders of Tomorrow, which was supported by the Department for International Trade.

The award of the grant was announced at the launch event of new governmental body Great British Nuclear (GBN), which took place earlier today at the Science Museum in London. GBN is part of a raft of new initiatives that represent a renaissance of the UK nuclear sector, and the grant will ensure that MoltexFLEX is at the forefront of this.

MoltexFLEX is continuing to work with prospective partners to deliver its first reactor at a UK site around the turn of the decade, while also engaging potential customers around the globe.


Notes to editors

The FLEX reactor is a revolutionary design that employs separate molten salts for the fuel and coolant. The fuel salt uses standard 5% low-enriched uranium. UF4 is a possible feedstock for the fuel, but it is generally derived from UO2, which means there would be some level of undesirable oxygen-based impurities.

A better approach is to directly reduce UF6 to UF4 with sodium, and the NFF grant will enable MoltexFLEX to demonstrate this process at pilot scale and to develop the blueprint of the process for a full-scale manufacturing plant.

MoltexFLEX has developed significant proprietary data on fuel design and is expecting to partner with a major fuel supplier to establish a pathway to commercial production.