More billions for fusion?

More billions for Fusion?

Climate change worries many of us, but in the back of many peoples mind is the belief that technology will come to the rescue. One of the big hopes is nuclear fusion- not messy uranium fission, with all its problems, but allegedly clean and hopefully prolific hydrogen based nuclear fusion. However, it’s a long time coming – and it’s costing a lot. $20 billion so far globally and more soon.

In response to a Parliamentary question in April, it was reported that the Government provided support for nuclear fusion research in the UK through the Engineering and Physical Sciences Research Council with an allocation of £26 million for 2007-8.
In addition it was noted that ‘The UK does not fund international fusion research directly, though it contributes to the Euratom European fusion research programme through its payments to the EU budget’. The main focus for that programme is the ITER project, now being planned at Cadarache in Southern France. The estimated cost of ITER has risen from £9 billion to, reportedly, around £18 billion. It’s a joint EU, Russia, US, China, Japan and S. Korea project toward which it seems the UK is contributing around £20m p.a.

For comparison, in response to a Parliamentary question on 25 March, it was reported that government expenditure on research and development for all the renewable energy sources in 2007-8 was £ 15.92 million via the Research Councils and £ 7.53m via the Technology Strategy Board. In addition it was noted that the Research Councils are providing funding of £13.88m over the period 2004-09 for the UK Energy Research Centre (which undertakes a range of research relating to renewable energy) and energy is included in the work of the Tyndall Centre for Climate Change Research (which has some £15.8m funding from the Research Councils over 2000-08).

At most then, in total renewable are getting around £28m p.a. at present. That is pretty much the same as it was decades ago, even ignoring inflation since then. For example, according to DTI statistics, Departmental funding for renewables was £24.8m in 1991-92, £25.6m in 1992-93 and £25.2m in 1993-94, all in ‘money of the day’ terms, though it fell off thereafter, as the then Conservative government imposed public sector spending cuts.

Why fusion?

Fusion is clearly getting favourable treatment compared to renewables- which after all include a wide range of technologies, a dozen or more very different systems, not just one. Does this make sense? The claim is that it offers, as the EURATOM web site says, ‘an almost limitless supply of clean energy’.

The prospects for fusion are actually rather mixed. The physics may be sorted, up to a point. The UK’s JET experiment at Culham managed to generate 16MW briefly. But the engineering is going to be complicated. How do you generate electricity from a radioactive plasma at 200 million degrees C? The answer it seems is by absorbing the neutron flux in a surrounding blanket that then gets hot, and has pipes running through to extract the heat, which is then used it to boil water and raise steam –as with traditional power plants. Not very 21st century…

As yet, few people would hazard a guess as to the economics of such systems. The ITER web site (www.iter.org) says ‘it is not yet possible to say whether nuclear fusion based on magnetic confinement will produce a competitive energy source’.

But at least there won’t be any fission products to deal with. However, the neutron flux will activate materials in the fusion reactor which will interfere with its operation, and will have to be stripped out regularly- so there will still be a radioactive waste storage problem, albeit a lesser one. The materials will only have to be kept secure for a hundred years or so, rather than thousands of years as with some fission products.

The risk of leaks and catastrophic accidents is said to be lower than with fission. Fusion reactions are difficult to sustain, so in any disturbance to normal operation the reaction would be likely to shut itself down very rapidly. But it is conceivable that some of the radioactive materials might escape, if for example the superhot high energy 'plasma' beam accidentally came into contact with and punctured the reactor containment.

The main concern is the radioactive tritium that would be in the core of the reactor: Tritium, which is also used in nuclear weapons, is an isotope of hydrogen, and, if accidentally released, could be easily dispersed in the environment as tritiated water, with potentially disastrous effects. To put it simply, it could reach parts of the body which other isotopes couldn’t.

Finally what about the fuel source? The basic fuels in the most likely configuration to be adopted would be deuterium, an isotope of hydrogen, which is found in water, and tritium, another isotope of hydrogen, which can be manufactured from Lithium. Water is plentiful but lithium reserves are not that extensive, at least on this planet. Even so, it is claimed that they might provide sufficient tritium for perhaps 1000 years, depending on the rate of use. It also presumably depends on the competing use in Li Ion batteries in consumer electronics and possibly soon, on a much larger scale, in electric vehicles.

That could be a problem for the future, but there is a long way to go before we need worry about fuel scarcity. The ITER project is small (500 Megawatt rated) and won’t start operating until 2018, and, even assuming all goes well, it’s only a step toward a commercial pilot plant. And that at best is decades away.

Too little, too late

The UK Atomic Energy Authority say that fusion ‘has the potential to supply 20% of the world’s electricity by the year 2100.’ That’s not a misprint – 20%, if all goes well, in 90 years time. Renewables already supply that now globally, including hydro, and the new renewables like wind, solar, tidal and wave power, are moving ahead rapidly. Wind power capacity is at 120,000 Megawatts globally now and expanding at around 30% per annum. Given planning permission, wind farms can be quick to install, in a matter of months, compared to years or even decades for fission projects. Solar thermal is at 120,000 Megawatts (th) and also expanding rapidly, with Concentrated Solar being the next big thing, along with PV solar, which is even quicker to deploy- we’re talking weeks if not days. Then come wave and tidal- a huge as yet mainly untapped resource. By 2020 the European Commission wants to have 20% of the EU total energy, not just electricity, coming from renewable, and there are scenarios with renewables supplying 50% of global energy by 2050, and perhaps earlier.

By contrast, fusion seems likely to be a long-shot high-tech gamble with a surprisingly small payoff: we need to start responding to the climate problem now, not in 90 years time. Renewables, along with energy efficiency, already offer us at least part of the solution. So why then are we spending so much taxpayers money on fusion? It might eventually be useful for powering space craft. But on Earth? Wouldn’t it make more sense to speed the development and deployment of full range of renewable technologies, and make use of the free energy we get from the fusion reactor we already have- the sun.