Salt reactor is secret ingredient for power plant developed in Britain

Each Flex reactor is about the size of average two-storey house and has the potential to power 40,000 homes

Sizewell B nuclear power station in England. Moltex says it can provide energy more cheaply and efficiently. WPA

A molten salt reactor has been unveiled, developed by a British company which says it can offer a low-cost alternative to nuclear technology.

Energy company Moltex said its plans to have its first reactors operational by 2029 and that its 500 megawatt plants can be built in only two years.

Moltex, in Warrington, north-west England, said its salt reactor is a complement to wind and solar energy, and an energy-providing option cheaper than nuclear power.

The Moltex Flex, a molten reactor using salt as fuel and coolant, has no moving parts, the company said.

“We recognised the need for an energy supply that can support renewables when the sun doesn’t shine or the wind doesn’t blow," said chief executive David Landon. "In the Flex reactor, we have a solution for consumers and countries alike.”

The reactor can respond automatically to changes in energy demand — moving to idle or full power — to work in tandem with wind or solar power plants.

Moltex said it has the flexibility of gas-fired power stations without carbon emissions.

Energy production and independence has swung into focus this year as the war in Ukraine broke out and fears grew over the dwindling supply of gas from Russia. Energy prices had already been rapidly increasing, contributing to inflation across Europe.

A fourth gas leak has been found in the Nord Stream gas pipelines in the Baltic Sea, with some experts suspecting sabotage.

Each Flex reactor is about the size of an average two-storey house and has the potential to power 40,000 homes for about £40 ($44) per MWh.

The system uses two molten salts: one acting as a fuel, the other circulating as a coolant. This system allows heat from the reactor to be extracted through natural convection, without the need for pumps.

In turn, that rules out the need for steel and concrete buildings, reducing operational and maintenance costs.

Once up and running, the Flex reactor can last for 60 years with only two scheduled breaks to refuel.