Fusion- next steps for the UK

Nuclear fusion is being talked up as the next big energy thing- although it remains some way off and there are many technical and economic question marks. But Boris Johnson is evidently a fan. The UK government, keen to maintain headway in this field after the UK’s exit from Euratom, has set aside £222m for the development of new fusion technology. 

It has also asked local authorities to nominate potential sites for a prototype fusion plant, based on the MAST Tokamak developed at Culham in Oxfordshire. The Atomic Energy Authority will assess the sites before making recommendation to the Secretary of State for Business, Energy and Industrial Strategy. Candidate sites for the ‘Spherical Tokamak for Energy Production’ (STEP) project include Ratcliffe-on-Soar power station, Nottinghamshire and Aberthaw Power Station, near Barry, in Wales. With there being concerns about local job as coal plants close, new projects like this are obviously attractive, but the STEP programme is fairly leisurely, with a commercial-scale plant not being expected until 2040. 

The basic requirement for a viable fusion plant is to be able to sustain fusion reactions between relatively easily obtained hydrogen isotopes in a plasma of superhot gas for long enough to get more energy out than is needed to run the system. ITER, a very big 500MW rated conventional helical tokamak prototype, is being built with international support in France, but the STEP programme offers a possibly faster route using a much smaller spherical device. To make that viable you need higher power superconducting magnets to sustain/contain the plasma. The STEPs team have come up with a way to put thin layers of superconducting rare-earth barium copper oxide (ReBCO) on metal tape. The team says that the technology should be deployable in a test fusion pilot plant ‘in the early 2030s’. 

However, they are not alone. First Light, an Oxford University spin off company based in an industrial park in Oxford, are developing a novel inertia confinement system. And Canadian company General Fusion is to build and operate a demonstation Magnetised Target fusion plant plant at UKAEA's Culham Campus near Oxford. It involves injecting hydrogen plasma into a liquid metal sphere, where it is compressed and heated so that fusion occurs. The company, which is backed by Amazon’s Jeff Bezos, says its goal is to bring fusion energy to the world by the early 2030s. There are also pioneering projects underway in the USA and elsewhere - some with 2030 targets. Though there is some debate over target criteria and what counts as operational success- presumably a real total energy gain. And also debates over safety, security, environmental impacts and of course costs. 

It is very early days for these novel technologies, but there have been assessments made of health and safety risk factors in relation to ITER-type reactors, a key one being the creation of X and gamma ray activated containment materials from the powerful internal radiation fluxes.  So, as a Nature paper explained, even though they will be shorter lived than the waste produced by fission reactors, ITER-type plants will produce wastes that have to be dealt with, and will need shielding and careful access control to protect workers and the public. All of which will add to the cost. 

It is rare to see much in the way of convincing analysis of costs - with so many different still developing technologies and little work done yet on exactly how the neutron energy released by fusion reactors would be converted to electricity, it’s too early to say. ITER’s web site says that the average cost per kilowatt of electricity is expected to be similar to that from a nuclear fission plant ‘slightly more expensive at the beginning, when the technology is new, and less expensive as economies of scale bring the costs down’. 

However, there are other views: one study in 2018 put the estimated mid-range capital cost of an ITER-type commercial plant at roughly twice that from on shore wind, although it claimed that the average cost of energy would be similar, while it would be cheaper than wind when external (impact) costs were added. That is very surprising and seems to be based on the assumption that fusion plants’ external impacts would be tiny, whereas it has been argued that there could be significant issues e.g. from the release of radioactive tritium. 

The smaller inertia confinement systems may of course turn out to be cheaper since they do not need large complex energy-hungry magnetic containment systems. First Light has claimed that it could deliver a Levelised Cost Of Energy (LCOE) as low as $25/MWh compared with $100/MWh for conventional nuclear energy and up to $50/MWh for onshore wind. However, that is all very speculative, whereas one thing has been clear, year by year renewables like wind and especially solar PV are getting cheaper. 

Despite all these uncertainties and concerns over technical and operational viability, there is a lot of optimism about fusion, for both ITER and for the national programmes going on in parallel. However, it sometime involves over-egged media attention alluding to imminent breakthroughs. In reality, ITERs development programme stretches out decades ahead, with the first test run maybe in 2035, but, even if all goes well, it seems from project planning reports that a commercial-scale ITER follow up is not likely to be available to feed power to the grid until well after 2050!  

However, some of smaller rival projects may beat it to the market. In that regard, the UK and USA are reputedly in something of a race and China and South Korea are also in the game. It will be interesting to see how it plays out. There have been some perhaps rather optimistic claims by developers. For example, in 2014 Lockheed claimed that for their ‘compact fusion’ programme they were aiming for a ‘prototype in 5 years, defence products in 10, clean power for the world in 20 years’. That raised some eyebrows.  It will probably take longer that that for any of the schemes. Possibly much longer. In which case there is no way that fusion can help deal with the urgent problem of climate change, which raises the question – why is so much being spent on it?  Perhaps $20 billion globally so far and at least that again now likely to be invested in new research programmes. 

It may be reasonable to mount smallish long-term programmes, since, at some point in the future, we may need a power source for deep space travel, not least to get access to the helium 3 from the asteroids in order to run fusion reactors: given its use for electric vehicles, we may run out of lithium for tritium production. But why bother with the huge effort to get fusion plants running on earth? We have the sun, a free fusion reactor in the sky, that delivers all the energy we could ever need, without charge. And the technology needed to use it is available now, not, at the very best for fusion, in a decade or two, and more likely not until 40 years on…