Published September 2007

Visit to see Culham’s Nuclear Fusion Power Projects

The visit was on the 23rd May, one of those hot, sticky days of early summer. It started with a lecture theatre presentation on the basics and continued with a tour around the facilities by guides from Culham’s technical staff.

At Culham there are basically two projects relating to the overall objective of producing electricity by way of nuclear fusion. They are; the Joint European Torus (JET) and the Mega Ampere Spherical Tokamak (MAST). In both the focus is on producing heat by nuclear fusion, since the production of electricity from heat is by conventional means, i.e. heat is used to warm water, to produce steam, to power steam turbine driven electrical generators.

JET, the oldest of the projects, currently includes financial contributions from mainly western EU countries, together with Finland, Sweden and Switzerland. The design team started work in 1973, construction started in 1979 and first operation began in 1983. There has been a sea of problems to overcome; making, evacuating and maintaining the vacuum in such a large vessel, generating, guiding, controlling and maintaining a plasma beam suitable for producing the necessary nuclear reactions, increasing beam strength to allow useful power extraction, extracting power in the plasma beam to allow the production of electricity and determining radiation levels, and materials to withstand the radiation over a prolonged period and minimise radioactive waste products.

There have been advances along all the research fronts to the point were the focus of effort may be described as increasing and sustaining beam strength from the very small, very intermittent beams that were produced in 1983, to larger currents lasting over ten seconds that can be produced today. Since the beam is circular, in the current design about 3m diameter, large magnets are needed to keep it in place and these unfortunately consume a great deal of electricity themselves. To counter this, i.e. to produce more electricity than is consumed, the plasma beam power needs increasing but unfortunately this makes it more difficult to control and so maintain.

The current equipment is just capable of producing more electricity than it consumes but still the plasma controllability is a major handicap to making it generate so much electricity that becomes economically viable. However, research to date has shown that one aspect of the design is almost unopposedly in its favour, physical size. The larger the machine can be made the easier it will be possible, all other things being more or less equal, to control and maintain the plasma beam and so generate a surplus of power. As a result it has now been decided to build a considerably larger machine at St Paul-lez-Durance near Marseille in France. Its goal; ‘to demonstrate the scientific and technological feasibility of fusion power for peaceful purposes.’ The name of the project set up to do this is ITER.

Work began on the second project, MAST, in 1999. This British initiative, predominantly British effort and predominantly British funded project has the primary objective of producing a more compact design. As a side benefit it produces information useful for ITER and so gets a small measure of funding from the European community. Features that the MAST project includes to help gain information to help the ITER project are; adaptable fuelling and heating systems, digital control systems to produce tighter control and extensive and advanced diagnostic features to test features and facilitate data collection that should better define ITER’s operating envelope.

In spite of the above some may think the MAST project smacks of the age old British failing of running up R&D bills introvertedly pursuing perfection, rather than pushing to get a speedy financial return to stimulate the ever greedy market place to self interestedly ‘fall over itself’ to provide funding for the subject in general. By contrast consider what a beastly monster, not least conceptually, the conventional reciprocating internal combustion engine basically is, yet look how well it has evolved with liberal funding provided enthusiastically by an appreciative market keen to achieve any form of cheap mobility. Consider all the exotic nuclear fission reactors Britain developed in past years, at great expense and delay and heartache, compared to the simple heavy water reactors. Heavy water reactors that are used almost universally elsewhere in the world and which have evolved well enough to produce sufficiently reliable, safe, power.

Of overall note is that there has been international collaboration into how to produce electricity by way of nuclear fusion for nearly forty years. Some of you may recall that it was being said forty years ago that it was hoped nuclear fusion plants would be producing electricity in about forty years time. If so you will no doubt be thinking, ruefully that here we are, forty years later, and it is still being said that it will be forty years before nuclear fusion produces commercial electricity. It is tempting to say, “What on earth has been going on all this time”, but clearly much has. It is just that the ‘end’ is still far from sight, although appearances are now that at least the ‘light at the end of the tunnel’ is said to be finally growing steadily larger. Perhaps part of the problem is that to the general populace, including politicians and the majority of media personnel, science is a black art to be mistrusted. They are proud not to understand it, they don’t understand the subtlety of what they are told about it and they easily run away with their over simplified misunderstandings which they have a detrimental ability to magnify. Consider the hospital’s name, MRI, for what we know as an NMR machine, because of patient’s fear generated by the word ‘nuclear’. Or Britain’s powerful opposition to nuclear power, in part due to fear of a Chernobyl like occurrence, when one considers that we buy nuclear generated electricity from France, which has almost sixty nuclear power stations, many far closer to the heavily populated parts of Britain than most of Britain’s own nuclear power plants.

The overall expenditure on the projects to produce nuclear electricity by way of nuclear fusion have been miniscule by British standards, never mind European standards, or world standards, when compared to the amounts spent on trying to achieve continuity and security of alternatives, e.g. oil and gas supplies. Almost all the wars in the near and middle east since 1900 have had that as a major objective and it looks as if the way the world is aligning for the future the trend is sure to continue as vigorously as ever it did in the past. There are now more ‘hungry’ players than during the last century.
Consider merely the latest bout in the Middle East. As an ‘up front’ cost the US has spent well over 400 billion $ US in three years. That is just to destroy things; the cost of rebuilding will be many times that. And then there are the growing costs of measures to increase ‘security’, in part due to that venture, but also to earlier ‘mess ups’ connected with earlier efforts to achieve or maintain hegemony. Compare these costs to the mere five billion Euros, circa six billion $ US) over the next ten years that together the many national contributors plan to fund ITER with. Money, remember, is only an easily convertible trading means for resources, world resources, resources, e.g. oil, gravel, lime, timber, steel that are increasingly costly to produce or recover. So, as you probably all realise as engineers, such things as windmills, solar panels and better insulation although useful contributions to answering the problem of the world’s energy shortage are by no means the answer. Cheap, economically, sustainable base load power production is required. At present the greatest hope for this is nuclear fusion plants. I think we all ought to do our bit to help educate the public to so perhaps influence the politicians. After all, your efforts don’t have to be too taxing. What about over a pint or two, or if that doesn’t sit will with your beliefs, over a cup of coffee or a plate of nuts, or ….. And don’t forget that almost the most wasteful thing you can do with gas, or oil or coal is burn it. They are in themselves wonderful starting points for the production of a multitude of products from fertilizer, through plastics to lipstick. Besides polluting the earth as we burn the raw materials what are we going to do when they have gone, even if, by then we have cheap, sustainable energy from nuclear fusion.

Well, Britain’s general nulearphobe stance, compared with France’s general nuclearphile stance, is resulting in the next major step in the development of Nuclear Fusion power technology moving across the Channel. To France will go the ‘spin off’ benefits of a lift to their local economy, paid for by the other participating partners. Spin off in terms of additional infrastructure e.g. roads, international school, and doorstep development of the technology and workforce. Today we are importing builders from Poland; in times to come it will be the nuclear engineers and technicians from France. They already have a vast pool of them. I wonder who wants all our media studies graduates.