A new report by a retired nuclear expert for the Global Warming Policy Foundation (GWPF) says there are ‘intrinsic concerns for commercial fusion’, as currently being explored by the large scale ITER device being built in France. It says issues included:
• excessive cost compared to fission, because of its enormous size and complexity;
• low operational availability due to the necessity to frequently replace components damaged by neutron irradiation;
• scarcity of tritium fuel, requiring regeneration in operations and probably supplies for start-up from a fleet of fission reactors.
The GWPF report ‘Nuclear fusion- should we bother?’ goes on to look in detail at the issues ITER and the mainstream approach face. It is pretty damning. As the author Dr John Carr says in the press release ‘there is a litany of technical difficulties, from degradation of materials due to radiation damage, to lack of tritium fuel supply. Progress towards a working reactor has been dismal, and the problems may be insuperable’. Even if it can be done, he says, ‘the costs of electricity from a fusion reactor are likely to exceed those from fission by a factor of ten or more.’
His main focus is ITER, but, in the report he notes that there are a some alternative projects, mostly privately funded. He says that ‘some private companies have possible remedies for the first two points [in his issues list above], through use of high temperature superconductors. However, these solutions raise new challenges and it is highly likely that the timescales to develop the new technologies will be very much longer than the commercial promises’.
Nevertheless, there are evidently many willing to try their luck. The report notes that ‘by 2023 there were a total of 43 major companies involved, of which 24 had declared funding of more than $10 million. The majority of these companies (15/24) are pursuing alternative concepts, while some (9/24) are building toroidal magnetic confinement devices, such as compact tokamaks, which are variants on the mainstream approach. A few of the companies (5/24) are proposing the use of alternative fuels. Many were founded by frustrated academic researchers, and all obviously want to avoid the pitfalls of mainstream fusion’.
It goes on ‘The arrival of the private fusion companies, making claims for commercial fusion power stations to be connected to the electricity grid in the early 2030s, has the potential to dramatically change the prospects for the technology. This commercial optimism will compete with technological reality during the next 10 years; the oldest private fusion companies, including TAE, have already passed the original dates for which they promised commercial fusion. Such claims must therefore be taken with a pinch of salt. In parallel with these private company claims, ITER will have to readjust to a new schedule for fusion reactions after 2035. So, should these private companies succeed, it will be difficult to see why the ITER/ DEMO programme would continue’.
Well yes, it could be overtaken, but, given the problems it identifies, the report does not in fact see the alternative fusion options as developing rapidly or effectively, so that, it concludes that overall ‘there is no reason to bother with fusion. It will almost certainly have no advantages over fission and will come – at best – a hundred years later than the Calder Hall milestone [i.e. 2056], costing vastly more. The timescale for fusion is such that it has no relevance for the reduction of climate-changing carbon dioxide emissions’.
That may be too conservative, even for the GWPF! John Carr may be right about ITER. And also some of the alternatives. He is certainly pretty dismissive about most of them. For example, he notes that ‘TAE is studying the use of proton-Boron to replace D-T, because Boron is both abundant and the reaction produces no neutrons. The snag is that this fuel requires 6 times the reaction temp. of D-T (> 1 bn degrees). Critically, the radiation losses in the plasma are higher, to the point where an energy gain is impossible, according to calculations. It is surprising that this company, which has prospered for 25 years, is advocating a technology that many experts say can never work’.
He looks at Commonwealth Fusion System’s ARC tokamak design, which uses high-temperature superconductors (HTS), in the form of the new rare-earth barium copper oxide (REBCO) material, rather than the usual superconductor of niobium-tin and niobium-titanium used in ITER. Using HTS allows ARC to use higher magnetic fields and thus be smaller- half the physical size of ITER for a similar fusion power output. That would reduce costs. CFS gives a cost estimate for ARC at about $6 bn, compared with ITER’s $60 bn.
However, the report says ‘The REBCO superconductor is brittle – being a ceramic rather than a metal. In addition, the use of higher magnetic fields results in greater mechanical stresses, so constructing reliable magnets is more difficult. Further, the smaller size means the same fusion power output must be extracted through smaller breeder blanket systems and divertors, requiring these devices to sustain higher temperatures and radiation doses – another major challenge’. It says it’s similar for the UK’s spherical STEP.
Well maybe, but what about some of inertia/laser systems being developed in the USA- there’s almost no mention of them. There is certainly a lot of hype about imminent breakthroughs with laser ignition, but, arguably, at some point, there might be some real progress in this area- or in others. However, in addition to costs and safety, the key thing is when? We need to deal with climate change now, not in many decades times. In that sense then Carr may be right- forget fusion for now. It’s not as if there are not other arguably much better (and urgent) things to spend the money on, although, given its hostility to almost all things green, the GWPF is probably not the best outfit to rely on for advice as to what the focus should be!
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