Engineering news
The company behind the development of a nuclear fission molten salt reactor is raising £8 million to develop its first prototype, while warning that the first demonstrator is likely to be built outside of the UK.
Moltex Energy is in discussions with governments and companies around the world about funding the next stage of its reactor’s development, a prototype demonstrator and regulatory approval.
Dr Ian Scott, inventor of the Stable Salt Reactor and co-founder of Moltex Energy, told PE: “All the key novel elements have been validated at the theoretical level. The fundamental chemistry is well-established. We have a strong patent position. The demonstrator doesn’t have to be in the UK – we need a site and location where regulatory resource is readily available.”
Molten salt reactors use ionic salts for both the reactor coolant and to carry the dissolved reactive material as fuel. The salts are efficient for transferring heat. The reactors can use a wide range of fuels, from legacy waste to enriched uranium.
The reactor designs feature passive safety and are said to be relatively cheap and simple to construct. Research in molten salt reactors was conducted in the US and the UK in the 1960s and 1970s, but designs were not developed for civilian use.
Scott said the development team had shown that no special steels needed to be developed for the design, saving years off the development time for the reactor.
In the Moltex design, the salt is held in vented tubes, which is possible because the fission products form compounds in the salt. These tubes are bundled into fuel assemblies, which in turn form the reactor modules. The tank is filled with the molten salt coolant, which is not pressurised as it is in gas- or water-cooled reactors. Refuelling is achieved by moving fuel assemblies sideways out of the core. The design has no high-pressure systems, few moving parts, and is continuously cooled by natural air flow. It does not require a pressure vessel from a specialist foundry, said Moltex.
According to Scott, initial Moltex costings put the cost of electricity produced by a full-scale reactor at $1,000/kW capacity – substantially lower than the cost of nuclear power stations such as the proposed new reactor at Hinkley Point. A 150MW demonstrator salt reactor will cost up to $500 million to build, he said.
Mike Middleton, strategy manager for nuclear at the Energy Technologies Institute, said: “Molten salt reactors sit in that basket of reactor concepts and designs that should be funded. The concept hasn’t been funded or developed like gas-cooled or light water reactors. There is debate about how long it will take to build a demonstrator, but the technology is worthy of research and development.”