Molten salt nuclear reactors to power 40,000 homes

Plans to construct a nuclear reactor fueled by molten salt by the end of the decade have been unveiled.

UK-Canadian innovator Moltexflex has outlined plans to roll out the technology from its base in the north west of England.

Each Flex reactor, roughly the size of a two-story house and using a pair of molten salts – one as a fuel instead of traditional uranium pellets, one as a coolant – has the potential to power 40,000 homes according to the firm.

It’s forecast that each 500MW plant could take two years to build – significantly shorter than the lead time for traditional nuclear plants.

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Versatile technology

Moltexflex’s system harnesses two molten salts – a mixture of sodium fluoride and uranium fluoride produced from the existing uranium enrichment process as a fuel salt, and a coolant salt very similar to the synthetic cryolite used in aluminium smelters.

According to the firm, the fuel salt replaces the uranium oxide pellets which normally fill fuel pins in a nuclear reactor, meaning that radioactive fission products are chemically converted to stable non-volatile compounds that cannot be released though the atmosphere.

The coolant salt replaces water used to cool the reactor core in conventional reactors meaning that the reactor operates at atmospheric pressure and avoids potential loss of cooling and explosion when water flashes to steam if there is a failure in the pressure boundary.

Designed with no moving parts according to the team of scientists behind the technology, the reactor can also respond to changes in energy demand given its ability to rapidly switch between an idle state and full power, thereby having the potential to dovetail with intermittent solar or wind power.

Once online, each reactor can last 60 years with only two scheduled breaks to refuel.

The main radioactive waste product is spent fuel, the bulk of which can be recycled with the remainder having a hazardous lifetime of between 200 and 300 years versus the thousands of years from traditional nuclear waste.

It has also been suggested that the 750°C heat produced from the process could be used for water desalination and more efficient hydrogen production.

“The reactor provides the safety net of affordable domestic energy, but is versatile enough for applications ranging from decarbonising heavy industry to powering cargo ships,” David Landon, chief executive officer at Moltexflex said.

New nuclear innovation

Moltexflex’s announcement comes after the strategy for energy security in Great Britain set out in April 2022 sharpened the government’s focus on new nuclear.

It stated that a new government body, named Great British Nuclear, would be set up to help deliver 24GW of nuclear capacity by 2050 alongside the launch of a £120 million Future Nuclear Enabling Fund.

More recently, the Department for Business, Energy and Industrial Strategy (BEIS) earmarked £3.3m in funding to boost the next generation of homegrown nuclear tech harnessing novel and innovative fuels, coolants, and technologies. Six projects to develop advanced modular reactors in the UK were each offered up to half-a-million pounds in funding to support early-stage innovation.

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