The global project of thermonuclear fusion is stalled: the Europeans are penny-pinching, the Asians are toying with risky nuclear power.
© Michiel de Boer - iStockphoto.comOne of the most expensive research alliances in history could explode before it succeeds in fusing its first nuclei. An energy-hungry club of states representing approximately half the world's population wants to tame solar fire in the South of France, where research reactor Iter is to fuse atomic nuclei.
And finally, after 50 years of basic research, demonstrate that energy can be generated on Earth according to the principles of the sun (two hydrogen nuclei become a helium nucleus). Mankind's dream of endless, clean power should be more enticing than ever in these times of growing energy consumption, fuel scarcity, climate change and oil spills.
But there's still nothing to be seen in Cadarache, France, except a meticulously levelled building site. One of the world's largest research projects is stalled, it may even be about to collapse. Because its development is becoming a continuous test of patience. And also because the cash is not flowing. The giant's price has just gone up again: it is expected to cost 15 billion euros, three times as much as originally projected. The EU alone will now have to find 7.2 billion euros, Germany up to 1.2 billion - in times of hotly debated austerity packages.
The Iter Council, the project's supervisory board, is meeting in Shanghai on Wednesday and Thursday of this week. On the agenda is the future of the energy machine. The EU states have already been discussing how to raise more money since late May. So far they have been unable to agree, a proposal is expected by next week at the earliest.
Tamed suns - Iter factsIter is Latin for »the way«. The name says it all: what is to take shape in Cadarache in the South of France is more than a precursor of fusion fire modelled on the sun. The technology is intended for later use in power plants. To achieve this, the developers will have to succeed in locking hydrogen plasma into magnetic fields and heating it to 200 million degrees. The fuel will be radioactive tritium, which is continuously generated in the reactor shell and is bred from lithium. European, Japanese, Russian and American fusion researchers have been planning the technically highly sophisticated experimental Iter facility since 1988. China and South Korea joined the large-scale project in 2003; the number of partners increased to seven when India joined in 2005. Work on the plant was scheduled to begin in 2009, but to date the site is still empty. Once construction is completed in 2026, 20 years of intense research are to follow: How can the solar fire be optimally harnessed? Which materials are the most resistant to it? Which are suitable as fuel suppliers? Well over 50 years will pass before commercial fusion reactors can be taken into operation. At least.
Federal Minister of Research Annette Schavan has already publicly stated that the German government does not want Iter »at all costs«. Possibly the reactor would have to be built more cheaply. »The costs must be transparent and capped«, demanded her state secretary for research, Georg Schütte. Other European member states are also refusing to sign a blank cheque. Some members have allegedly even enquired of the EU Commission how expensive it would be to leave the project.
This at least is a political signal: as opposed to the exploding costs of so many large-scale projects, this time the logic of escalating commitments is not taking effect. »This is a real crisis«, says Stephen Dean, President of Fusion Power Associates. The American group is in favour of a fast transition from basic research to competitively operating power plants. Now however one has to wonder whether fusion energy is even affordable, says Dean. »This is certainly a difficult time«, agrees Karl Lackner of the Max Planck Institute (MPI) of Plasma Physics in Garching.
When the project's cost previously soared to a two-figure billion sum in the late 90s, things became too much for the USA. They left the Iter project in 1998. Back then, Lackner wooed and coaxed them for years. The Americans only returned when the cost had been cut back and the dimensions of the fusion reactor halved. »I don't think anyone will leave the project«, Lackner emphasises today, but he adds: »Iter urgently needs more efficient management. Then the current discussion could also represent an opportunity.« The mega-project's organisation is sluggish and complicated. It is considered a cost driver, along with increased material costs (metal prices!) and amendments to the old reactor designs (expensive special coils!). Seven partners are currently participating in Iter; in addition to the founding members USA, Europe, Japan and Russia, China, India and South Korea are also involved. But instead of paying for a central construction from a single pot (as was the case with the CERN research centre), each party is developing and building its own reactor parts - in order to boost its own research and economy and later have important expertise. Duplicated work and co-ordination issues are inevitable.
Last spring, William Brinkman, head of research in the US Department of Energy, thundered, »If I could get my hands on the person who suggested the current management structure, I'd wring his neck.« The EU agency Fusion for Energy comes under particularly strong criticism. »Its organisational structure is unfortunately pretty bad«, Jewgenij Welikow, head of the Iter Council, succinctly informed Russian prime minister Wladimir Putin. The EU Commission replaced the head of the agency in February; the Director-General of Iter is also to be replaced at the meeting in Shanghai. But this game of musical chairs will not solve the structural problems. According to Deputy Director-General Norbert Holtkamp, it's too late to change the fundamental organisation. But it can at least be streamlined. »The tasks must be better distributed«, says Hartmut Zohm of the MPI for Plasma Physics. »You wouldn't order each wheel for a car from somewhere different either.« Karl Lackner wants more power for the central Iter organisation and would like to see posts staffed according to expertise rather than national proportionalities.
But for now, the arguments about money take priority. The EU Commission has already demanded more from the member states. These in turn would rather tap into the EU budget. A loan from the European Investment Bank (as was provided for CERN) is also under consideration. The shortfall for 2012 and 2013 amounts to 1.4 billion euros in all. The Europeans are now asking themselves where savings could be made on the reactor: By leaving out a component here or there? By downsizing? That was already taken to the limit in the late 90s. And MPI researcher Zohm emphasises: »There's not much left that can be cut, every part has already been repeatedly reviewed.« As general rule, saving money costs time. And the project is already way over schedule.
Iter was initially supposed to be fully operational by 2018; now it will be at least 2026. »We could start building with the already allotted money and add some components later«, says Dean, outlining a possible compromise. »Then the politicians wouldn't have to justify a higher budget now.« The most likely outcome is that somehow, the Iter project will continue - for a very long time. Once the machine is finally up and running, the researchers will still have to prove that energy can be generated by fusion. The process is extremely complicated: the fuel, a mixture of the heavy and super-heavy hydrogen types (isotopes) deuterium and tritium, has to be heated to a temperature of up to 200 million degrees. This releases the nuclei from their electron shells; in the resulting »plasma«, nuclei can fuse. To prevent the plasma from touching the walls of the reactor and cooling off, huge electrically charged coils lock it into a cage of magnetic fields. When the nuclei fuse, neutrons are released. Modules in the reactor shell transform their kinetic energy into heat, from which turbines and generators could generate power.
Iter is to be the first fusion reactor to release more energy than is required to heat up the plasma. The researchers still have to solve three big problems: firstly, finding materials that can withstand the enormous heat and neutron bombardment for as long as possible. Secondly, containing the hot, volatile plasma in such a way that it is retained for as long as possible. Iter is expected to manage a few minutes - a proper power plant however would have to produce energy continuously. And thirdly, the reactor is itself intended to produce tritium, which in contrast to deuterium does not occur in abundance on Earth. The scientists plan to build lithium, a light metal that releases tritium under neutron impact, into the shell.
Even if everything works out as planned, it will be 2075 before fusion power plants can cover a significant share of the energy demand, the Iter organisation itself estimates. Many in the fusion community are losing patience in view of this - comparatively optimistic - prognosis. They are advancing the seemingly strange idea of a hybrid power plant that combines nuclear fusion and nuclear fission in order to solve the problems of one technology by means of the other: the neutrons from the fusion could split nuclei of moderately enriched uranium, thorium, or even atomic waste, making it possible to generate power, save uranium supplies and reduce nuclear waste. A smaller, cheaper fusion reactor would suffice, they say. In particular, it would not require a particularly resilient shell, as released neutrons would end up in the nuclear fuel. Russia, South Korea and most of all China are particularly interested in a hybrid of this type. The Chinese Institute of Plasma Physics in Hefei plans to build a prototype by 2020. The fusion reactor East, which performs important tests for Iter and will be world-class once its next construction stage is complete, is already up and running there.
On the remote Kexue Dao (»Science Island«) peninsula, in traditional socialist concrete buildings and shielded by overgrowing palm trees, 250 researchers are working on fusion. As recently as the 1990s they were still practising with a decommissioned reactor from Russia; in 2006 East was taken into operation, largely self-built. The Chinese have proudly decorated the metal egg with their national flag. »What they've done there in such a short period is incredible«, says Joachim Roth of the MPI for Plasma Physics. His colleague Karl Lackner isn't taking the deadline for the fusion-fission chimera from Hefei entirely seriously - as opposed to the ambitions of the Chinese and the technology itself. And while institute director Li Jiangang is keeping quiet ahead of the Shanghai Iter meeting, sources close to him say »There's still a long way to go, but we will continue to advance hybrid fusion.«
US Secretary of Energy Steven Chu has also described the mixed concept as an option; the British secretary of state for research has recommended taking it into consideration. What a change! For many years, advocates of nuclear fusion wanted nothing to do with the dark side of nuclear power; they even dropped the »n-word« and spoke only of »fusion«, the »clean energy«. That attracted research funding: Germany has invested 3.3 billion euros since 1974 - 135 million this year alone, a third of the energy research budget. But because new energy sources are today needed more urgently than ever, fusion is gradually in danger of being sidelined. Germany for example plans to drastically reduce the use of fossil fuels in the medium-term in order to meet its climate targets - while simultaneously ending the use of nuclear power. A replacement will be needed well before 2075. That nuclear fusion won't be available in time is already clear. »Whenever nuclear fusion power plants finally become possible, there may be no place left for them on the energy market«, says Wolfgang Liebert, speaker of the Interdisciplinary Working Group for Science, Technology and Security at the TU Darmstadt.
Critics would rather channel the millions in research funding into regenerative technologies. Solar cells, solar thermal power plants and wind turbines would have good chances on the market, says Liebert: »The technical difficulties have largely been overcome. Of course renewables have yet to prove that they can fulfil their promise on a large scale.« The fusion researchers would be happy if they had no greater problems.
From DIE ZEIT :: 17.05.2010
16. November 2017
16. November 2017