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Energy: Nuclear Fusion

I congratulate the noble Lord, Lord Taverne, on initiating this debate on fusion power. It is a matter of major strategic importance to the UK. I congratulate him on his excellent and complete speech. Much of what I say will parallel what he has said. No matter how seriously or rapidly climate change impacts on our lives, it is certain that the supply of clean, economical energy ranks third only to the supply of sufficient clean water and food as a top priority for human progress, even for human survival. We have recklessly used our supplies of oil and natural gas at a rate that, if sustained, will mean that economical sources of these easy, but environmentally damaging, resources are used up well before the end of this century. Alternative energy sources including solar, wind, wave and tidal are being developed and may in the next two decades become economically viable, but they are all intermittent sources and will inevitably have to be backed up by continuous, supply-on-demand sources. To date only two sources of continuous power have been demonstrated at practicably high power levels—that is, powers per facility approaching 1 gigawatt—and at costs similar to fossil fuels—that is, less than 10p per kilowatt hour in today's money—and which have long-term—hundreds of years—potential. They are nuclear fission and hydro power. Hydro power is, of course, only continuous provided that water supplies can be sustained and adequate geographical locations found. So where do we turn to find the ideal continuous, sustainable, clean, safe and economical source of energy? Nuclear fission may well meet our needs throughout the century and perhaps for longer through the development of fast breeder reactors, but such reactors pose serious proliferation problems and difficulties will remain with radioactive waste disposal which must be dealt with. The only source we have with the potential to solve our problems cleanly and satisfactorily is fusion. Of course, there may be sources that we have yet to identify, although those will no doubt have their own problems—Rumsfeld's unknown unknowns, if you like. Leaving those aside, we are left with fusion. That reasoning led the committee of the US National Academy of Engineering, of which I was a member last year and which was charged with coming up with the grand challenges for engineering in the coming century, to select fusion as one of only 14 challenges on the committee's final list. Those challenges covered the whole of engineering and included such divergent objectives as developing the means to understand the human brain and the supply of clean water. There was considerable debate about including fusion and scepticism about its practicality, as alluded to by the noble Lord, Lord Taverne, and I shall talk about that briefly in a minute. However, it was felt that fusion was the only known completely satisfactory solution to our energy needs and therefore must be included in the list. In favour of fusion, as we have learnt, was the international buy-in to the ITER project with the commitment of major nations including the USA, the European Union, Japan, Russia, China, South Korea and India. While there are other attempts to produce fusion on a practicable scale using high power lasers, such as Europe's HiPER project, it is generally accepted that these are a generation, or 20 to 25 years, behind magnetic confinement, such as will be used in the ITER and is used in JET, the Joint European Torus, mentioned by the noble Lord, Lord Taverne, which, of course, is a European-funded project, much to our benefit. I believe we receive more than £50 million a year to run JET. ITER will be the first fusion experiment to produce a long pulse of energy release on a significant scale. The aim is to produce 500 megawatts, which is 10 times the power input, for 400 seconds, or 300 megawatts for several hours. I spent half an hour this morning on the phone with Sir Christopher Llewellyn Smith, who was until last September the director of UKAEA Culham Division, which is responsible for the UK's fusion programme and for the operation of JET, and with his successor Professor Steven Cowley, getting an update on the UK programmes and ITER. Sir Chris is now chairman of the ITER Council. What I learnt was encouraging but, as I am sure the Minister is aware and as the noble Lord, Lord Taverne, has told us, there will be funding difficulties with ITER, partly because of the expanded international nature of the programme. There were only three partners at the beginning when the original cost estimates were made, and there are now seven. There is also a lack of experience in pulling together such a vast international project on a greenfield site. But the new design for the reactor is much improved, and confidence is high that the aims of the project can be met. As we have heard, fusion powers the sun through a process in which atomic nuclei are compressed together to form heavier nuclei, typically with the release of a highly energetic neutron. A small mass loss occurs, and this mass is transformed into energy. The process relies on the extreme temperatures and gravitational pressure encountered in the sun. We cannot replicate the high pressure here on Earth, except in thermonuclear bombs and perhaps with lasers, because the Earth is so much smaller. But we can produce fusion by producing higher temperatures than are encountered on the sun in a magnetically confined plasma. This is how fusion is produced in the JET at Culham, of which the noble Lord, Lord Taverne, has given an excellent description. There is no point in trying to explain further the physics and engineering of a tokamak here. Suffice it to say that the fuel, which comprises isotopes of hydrogen called deuterium and tritium, can be produced from lithium, which is in vast supply in our oceans. A few tons of lithium would power a 1 gigawatt fusion power station for a year, and the oceans contain trillions of tons of lithium, so there is no fuel problem. Supplies would last for millions of years. From a safety point of view, there is no possibility of a runaway nuclear reaction, as it is difficult enough sustaining fusion in the first place. The problems of radioactive products are minute compared to today's fission reactors. The practical difficulties arise because of the extreme measures that have to be used to produce very high temperatures and because of the difficulty in extracting the heat from the magnetically confined plasma. These are now engineering and materials problems, and the ITER and the associated materials research facility are designed to solve them. Most of the science has been done. Incidentally, much of the materials research, as we have heard, can also be pursued at Culham using its compact reactor. Despite the fact that our expenditures on fusion are, as we have heard, small compared to those of our partners—especially Italy, France and Germany—we are in an extraordinarily strong position in fusion development, with UK scientists and engineers playing key roles in the world's leading fusion projects. The Government must not lose their nerve in their support for fusion and underinvest as we have done in so many promising new fields of technology when the running gets hot. Fusion has the potential to become a major source of UK industrial prosperity by the middle of this century.