Experts have questioned Lockheed Martin’s claims that it is ten years away from deploying nuclear fusion as a practical power source.
The US defence contractor says researchers in its Skunk Works division – a blue-sky engineering team responsible for the U2 and Blackbird spy planes – are working on a new compact fusion reactor (CFR), which it believes will result in a working prototype in five years and a device capable of powering a warship within a decade.
Unlike conventional nuclear fission that relies on splitting atoms, fusion harnesses the same forces that drive the sun, subjecting hydrogen atoms to incredibly high pressures until they become a plasma and the super-hot atomic nuclei fuse together to release huge amounts of energy.
Lockheed has released few details about the proposed device aside from claims that its design could produce a 100MW reactor that could fit on the back of a large truck, but Professor Steve Cowley, director of the Culham Centre for Fusion Energy in the UK, has questioned the lack of clarity.
“There is no technical information or apparent progress so I am confused as to why they are making an announcement now,” he said.
“Lots of people can and have speculated but where are the results — for example what is the temperature achieved? What is the confinement time of the plasma? I’m very surprised that Lockheed would put out a press release that is so devoid of content. A lot can be said without compromising IP.”
The reactor described bears similarities to a concept called a ‘field reversed configuration’, according to Cowley, but this was examined in the 50s, 60s, and 70s and found to be highly unstable.
On its website Lockheed describes the design as a high beta concept, meaning that a large proportion of the magnetic field pressure generated by superconducting magnets to confine the plasma is put to use, rather than dwarfing the plasma pressure.
A high beta ratio denotes better efficiency due to the high energy costs involved in running superconducting magnets and also allows for a more compact design, but Cowley has questioned whether the device shown in a video on Lockheed’s website could accommodate the shielding needed to protect the magnets from high energy neutrons emanating from the plasma.
The reactor would use a combination of deuterium and tritium – both hydrogen isotopes – as a fuel source to generate nearly 10 million times more energy than the same quantity of fossil fuels, according to Lockheed.
Speaking in a Lockheed video, programme leader Dr Tom McGuire said the reactor will allow the “true atomic age” to start, adding that he envisages compact fusion reactors taking the place of gas turbines in power stations to provide a readily available source of emission-free energy.
“Our compact fusion concept combines several alternative magnetic confinement approaches, taking the best parts of each, and offers a 90 per cent size reduction over previous concepts,” he said. “The smaller size will allow us to design, build and test the CFR in less than a year.”
But Dr Joel Gilmore of Australian energy consultancy ROAM Consulting warned against using the announcement as a reason to delay transitioning away from fossil fuels towards renewables in the hope of future breakthroughs.
“Certainly, I’d welcome fusion as part of the world’s energy mix, but this announcement is a long way from a working prototype, let alone a commercially viable power generator,” he said.
“Fusion requires incredibly high temperatures and pressures, which is challenging, and a lot of people have been working on fusion for a long time. So I won’t get too excited yet. Even if successful, the big question is ‘what will fusion power cost’. It will be challenging to compete with the falling costs of conventional renewable energy sources.”