UK Minister for Energy Michael Shanks reportedly said that ‘Fusion has the potential to provide virtually limitless clean energy’. That’s a dream that some now see as getting a bit more real. The UK has form in this area. It was a pioneer in nuclear fusion, with the ZETA device built at Harwell in the late 1950s getting, briefly, a very good press: there was front-page newspaper coverage saying it was a breakthrough towards unlimited energy. Sadly, and embarrassingly, it turned out not to be the case.
However, the UK persevered with fusion over the years, for example playing host to JET, the Joint European Torus test unit at UKAEA Culham. And now the UK government has committed more than £2.5 billion over five years to new nuclear fusion, including £1.3 billion for UK Fusion Energy to deliver the STEP programme (a spin-off from Culham) in partnership with industry. A further £740 million is earmarked for research and development infrastructure and facilities.
Fusion is famously always ‘just around the corner’, but endlessly in need of ‘just a few more billion’. Does this new spending make any sense- at a time when the UK is allegedly strapped for cash? We are told that the 100MW STEP project may deliver a working prototype of a new spherical design in the 2040s, but there is no guarantee of that. The larger (500MW) ITER project, being built in France with international backing, may also, it is said, be running by then, but it has been bedevilled by delays. Major backers include the EU, USA, Russia India, Japan and China, but the UK pulled out of it (and Euratom) after BEXIT, and some say that very big ponderous multi-state funded projects like this are less likely to succeed than some of the rival smaller private sector projects.
In addition to some big national projects (in the USA, China and elsewhere) there certainly are some new entrepreneurial players offering a range of technologies for speculative investments in fusion. Just as there are these days for small fission reactor designs, with, so far, mixed fortunes - for example the pioneering Canadian SMR programme seems to have come unstuck. Fusion might seem to be an even more risky investment, with a long way to go before a commercially viable system might be available.
Perhaps unsurprisingly, given that it’s a new technology, some of the new batch of fusion pioneers do seem to have had problems, leading to delays and changed project completion targets. And, beyond initial glitches, longer term there all sorts of technical and economic unknowns and issues to face. For example, fusion reactors don’t need fissile fuel, but they do need tritium, which is scarce and hard to make. One current plan is to breed it in lithium blankets surrounding fission, or eventually fusion, reactors. That may be costly- and we are getting short of lithium (it’s used in modern batteries). We may have to look elsewhere in the solar system for it or substitutes longer term. But, as far as using it for fusion goes, there is a doubling up option. The lithium blanket surrounding a fusion core may also be used to convert the neutron energy released by fusion into usable power. The blanket would get super-hot when neutrons are absorbed. That heat would then be used to boil water to make steam for a turbo-generator, as in a conventional power station.
That may sound a bit steam-punk Victorian! But there are also some key definitely not Victorian health and safety issues with fusion. Once running, fusion reactors will generate intense neutron and gamma radiation fluxes, as well as radioactive tritium gas and activated containment materials. All that has to be dealt with - fusion does not produce highly radioactive long-lived fission products, but it does lead to active wastes. So, alongside the benefits, there are also some serious issues and worrying down sides. And it diverts effort, people and money from developing renewables.
However, the dream of safe, clean endless fusion energy lives on. That despite no one really knowing what it might cost in reality – even if it can be made to work safely and cleanly. At some point in the future that may be possible, and, arguably, that would be handy for off-planet use. But for now, all we have is some possible prototypes in a decade or so – with it being unclear if any of them will be able to produce more energy than is needed for their construction and operation i.e. with an EROEI (Energy Return on Energy Invested) ratio greater than 1. Later models, with improved systems, may be able to do that and maybe much more, some say, but for now, as a solution to the urgent problem, of terrestrial climate change, fusion still seems a non-starter… or a very long shot.
Unless of course there is a big breakthrough. Can we afford to wait for that? By contrast, renewables are ready here and now. Arguably they are a much better bet….using the fusion reactor we already have- the sun. Which, in effect, as far as humanity is concerned, will continue to have an infinite EROEI for as long as it lasts. We have got quite good at using some of this free energy on earth. The solar energy derived renewables are already supplying more than half of the power needed in many key countries at competitive costs, and there is massive potential for expansion- if funding is not diverted to the various nuclear options, including fusion.
However, not everyone sees it that way. For example, in a surprise conference vote, the Green Party of England and Wales has just reversed its long standing opposition to nuclear and its commitment to a nuclear phase out. It doesn’t mention fusion, but in a statement to World Nuclear News, Green Party Spokesperson for Energy and Net Zero, Carla Denyer MP, a former renewable energy engineer, said the Green Party now think that nuclear fission ‘can be considered low carbon’, and therefore it has ‘a role to play’. She added ‘This evolution of our policy does not commit the party to backing new nuclear, but accepts this power source is here to stay for now, while we transition to electricity generation based primarily on renewable sources’.
Well in practice, there are only a few old nuclear plants still running in the UK (the old AGRs and Sizewell B), so this policy isn’t as radical as it might seem - assuming it means the greens will still oppose new plants, including SMRs. But then it’s hard to see why the Party has bothered with making this small change. Instead, more creatively, if it wanted to make a 'positive' policy change on nuclear, it could have said that it would only support new or old nuclear (fission or fusion) if the plants could be used to back up variable renewables. But then none of the current plants can do that and neither of the new big EPR plants are aiming to do that, while it remains to be seen if any of the new proposed SMR plants can or will be run flexibly to balance renewables. So maybe a policy dead end?
And fusion? It’s a way off, so for now no one can say exactly how the power systems will be configured, but it seems unlikely that flexible operation will be easy or economic. Though thinking much more wildly, some say that maybe China is going to crash ahead with new fusion technology with a giant EROEI! So, if you believe that, then all bets may be off…
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