It hadn’t taken long after the final decision to build ITER at Cadarache for the project partners to start filling senior management positions. As expected, Japan’s choice for director general, Kaname Ikeda, the country’s ambassador to Croatia, was approved. Ikeda had held numerous government jobs relating to research and high-tech industry and had a degree in nuclear engineering – a suitably senior person to head such an international organisation, but not a fusion scientist. His deputy was Norbert Holtkamp, a German physicist who had a track record of managing big projects, having just finished building the particle accelerator for the Spallation Neutron Source at Oak Ridge National Laboratory in Tennessee – but again, not a fusion scientist.
These two couldn’t have been more different. Ikeda was every inch the Japanese diplomat: polite, deferential, immaculately presented. Holtkamp, by contrast, was laid-back, affable and liked to do things his own way. Even a few years working in the United States hadn’t squeezed him into the corporate mould – at ITER he managed to persuade the office manager to exempt him from the usual no-smoking rules so that he could puff cigars in his office. Below them were seven deputy directors, one from each project partner, and the recruitment continued in a similar vein, trying to keep a similar number of staff from each partner. It was a management structure designed by a committee of international bureaucrats and it would prove to be a millstone around the young organisation’s neck.
This new management team, whose leaders were new to fusion, included many researchers who had not been involved in drawing up the design for ITER, so the first thing they had to do was thoroughly familiarise themselves with the machine. They also had to check and recheck every detail of the design to ensure it was ready to be used as the blueprint for industrial contracts to build the various components of the reactor. Then there was the fact that the design was, by then, half a dozen years old and fusion science had moved on: now was the chance to incorporate the latest thinking into the design. So the new team appealed to the worldwide fusion community to come to their aid. They asked researchers to fill in ‘issue cards’ describing any aspect of the design that worried them or possible improvements that could be applied.
Fusion scientists weren’t shy in coming forward and by early 2007 the ITER team had received around 500 cards. They drafted in outside experts to help and set up eight expert panels to sift through all the concerns and suggestions. Many proved to be impractical and could be discounted, others required just minor modifications to the design, but a few required large – and expensive – changes. By the end of 2007 they had whittled the list down to around a dozen major issues and work still remained to figure out how these could be incorporated into the design without inflating the cost.
One of the most contentious concerned a new method for controlling edge-localised modes (ELMs), the instability that causes eruptions at the edge of the plasma that can damage the vessel wall or divertor – a side-effect of the superior confinement of H-mode. The solution already chosen for ITER was to fire pellets of frozen deuterium into the plasma at regular intervals. These cause minor ELMs, letting some energy leak out and so preventing larger, more damaging ones. But researchers working on the DIII-D tokamak at General Atomics in San Diego had come up with a simpler solution: applying an additional magnetic field to the plasma surface roughens it up, which also allows energy to leak out in a controllable way. The problem was that this additional field required a new set of magnet coils to be built on or close to the vessel wall, a potentially costly change at this late stage.
The ultimate goal of these early years was to produce a document called the project baseline. Thousands of pages long, the baseline is a complete description of the project, including its design, schedule and cost. The project partners were not going to sign off on the start of construction until they had seen and approved the baseline document. So the levelled site sat quiet and empty while the ITER team continued to wrestle with a paper version of the project.
In June 2008 the team presented the results of the design review to the ITER council, which is made up of two representatives from each partner. Despite their extensive whittling down of the many suggestions from researchers there were still numerous refinements and modifications to components including the main magnets and the heating systems, plus there were the additional magnet coils to control ELMs. These changes, the team estimated, would add around €1.5 billion to the cost. Nor did the original estimate of €5 billion for construction look that secure. The more the ITER team looked into the details of the design, the more they found that the designers of 2001 may have been overly optimistic and that the final cost could be as much as twice the original estimate.
It’s not uncommon for major scientific projects such as ITER to go over budget, but this ballooning price tag would be an especially hard sell because, since the founding of ITER in 2006, the worldwide financial crisis had swept through the economies of all the project partners. The delegations would not relish going back to their governments and asking for more money when ‘austerity’ was the new black. So the council sent the ITER team back to work with the instruction to nail down the cost completely so that there would be no more surprises. Nor did the council trust them to get on with it unsupervised. It appointed an independent panel, led by veteran Culham researcher Frank Briscoe, to investigate the project cost and how it was estimated. It also set up a second panel to study the organisation’s management structure.
A year later the team asked the council for permission to build ITER in stages. First they would fire up the machine with just a vacuum vessel, magnets to contain the plasma, and the cryogenic system needed to cool the superconductors in the magnets. The idea behind this was to make the whole system simpler so that operators could get the hang of running the machine without all the added complication of diagnostic instruments, particle and microwave heating systems, a neutron-absorbing blanket on the walls and a divertor, which would be added later. The council agreed and also approved a slip in the schedule: first plasma in 2018 not 2016, and first D-T plasma in 2026, nearly two years later than originally planned. The ITER team were still working on the project baseline, including that all-important cost estimate, but the council asked to see it at its next meeting in November 2009.
But the autumn meeting ended up being all about schedule. The European Union was concerned that finishing construction by 2018 was still too soon. Rushing the process could lead to mistakes that would be impossible to correct later. So ITER’s designers were sent back to the drawing board to do more work on the schedule. Other members of the collaboration were getting frustrated by the delays. They wanted to push ahead as quickly as possible but Europe, as the project’s biggest contributor at 45%, had the most to lose and so could throw its weight around. In the spring of 2010 a new completion date was agreed: November 2019. But still there was no baseline and the reactor’s home remained an idle building site.
Later that spring the true underestimation of ITER’s cost became apparent. The European Union was going to have to pay €7.2 billion for its 45% share of the cost. That put the total bill in the region of €16 billion. While this colossal figure would impose a severe financial strain on fusion funding for all the ITER partners, for the EU it caused a near meltdown. The problem was this: EU funding is agreed by member states in seven-year budgets; the current budget cycle ran until the end of 2013; the budget line for fusion in the years 2012 and 2013 contained €700 million; but the new inflated ITER cost required €2.1 billion from the EU in those years, so Europe had to find another €1.4 billion from somewhere.
EU managers considered a number of options to fill the gap, including getting a loan from the European Investment Bank, an EU institution that lends to European development projects. But this was rejected because there was no identifiable income stream to repay the loan. They considered raiding the budgets of EU research programmes but feared a backlash from scientists across the continent. In the end, they appealed directly to E
U member governments for an extra payment to get them out of a hole. In June member states declined to bail out the project, essentially saying this was the EU’s problem and it would have to find its own solution. The June ITER council meeting came and went with still no decision on the baseline.
With much persuasion and institutional arm-twisting, EU managers finally managed to cobble together the necessary funds from within the EU budget. Some €400 million was taken from other research programmes and the rest from other sources, in particular unused farming subsidies. The way was now clear for ITER to move forward.
On 28th July, 2010, the ITER council met in extraordinary session at Cadarache. Chairing the meeting was none other than Evgeniy Velikhov, again on hand to guide ITER through one of its major turning-points. With huge relief the national delegates approved the baseline, allowing ITER to move into its construction phase. But that was not their only item of business. They also bade farewell to director general Kaname Ikeda, who had asked to stand down once the baseline was approved. In his place, the council appointed Osamu Motojima, former director of Japan’s National Institute for Fusion Science. Motojima knew how to build large fusion facilities, having led the construction of Japan’s Large Helical Device, a type of stellarator. Ikeda’s was not the only departure following the baseline debacle. Norbert Holtkamp also stood down and his position of principal deputy director general was dispensed with.
Motojima’s mandate from the council was to keep costs down, keep to schedule and simplify ITER management. The latter he set about by sweeping away the previous seven-department structure and replacing it with a more streamlined three. The first department, responsible for safety, quality and security, was headed by Spaniard Carlos Alejaldre, who had filled the same role under the old structure. To run the key ITER Project Department, responsible for construction, Motojima appointed Remmelt Haange of Germany’s Max Planck Institute for Plasma Physics. Haange, like Motojima, was a seasoned reactor builder, having been involved in the construction of JET and as the technical director of Germany’s Wendelstein 7-X stellarator project. Finally, Richard Hawryluk, deputy director of the Princeton Plasma Physics Laboratory, was picked to head the new administration department. With these veteran fusion researchers at the helm, the project got down to the serious business of building the world’s biggest tokamak. Soon trucks and earth-moving machines were crawling over the site like worker ants.
Evgeniy Velikhov celebrates the end of his term as ITER council chair in November 2011.
(Courtesy of ITER Organisation)
Research into fusion energy is now well into its seventh decade. Thousands of men and women have worked on the problem. Billions have been spent. So it seems reasonable to ask, will it ever work? Will this amazing technology, which promises so much but is so hard to master, ever produce power plants that can efficiently and cheaply power our cities? Today’s front-rank machines, such as NIF and ITER, seem so thoroughly simulated and engineered, and the previous generation of machines got so close to break-even, that surely the long-sought goal can’t be far away? Let’s first consider the case of inertial confinement fusion and NIF.
At the time of writing it is still anyone’s guess whether NIF will ever be made to work. Many believe that it is just a matter of twiddling all the knobs until the right combination of parameters is found and suddenly everything will gel. But Livermore’s choices of neodymium glass lasers and indirect drive targets have always been controversial and critics say the whole field needs a complete change of direction, such as to krypton-fluoride gas lasers – which are naturally short wavelength – and simple and cheap direct-drive targets.
NIF cannot escape from the fact that its primary goal isn’t fusion energy but simulating nuclear explosions to help maintain the weapons stockpile. Nevertheless, when the machine was inaugurated in 2009 the press coverage focused almost exclusively on fusion energy. That was no accident. During the preceding years NIF’s managers felt which way the political wind was blowing: while maintaining the nuclear stockpile was still important, so was climate change and energy independence. If they were to maintain support for NIF from the public and Congress they had to broaden its appeal. Hence the emphasis on energy, not nukes.
NIF director Ed Moses and his team expected that when they achieved ignition it would spark a surge of interest in fusion energy and – hopefully – new money. They wanted to be ready to ride that wave of enthusiasm so, in traditional fashion, they started to plan for the reactor that would come next, one designed for energy production, not science or stockpile stewardship. Taking the achievement of ignition – which they expected soon – as their starting point, they sought to establish how fast and how cheaply they could build a prototype laser fusion power plant. They adopted a deliberately low-risk approach, sticking as closely as possible to NIF’s design in order to cut down on development time. All components had to be commercially available now or in the near future. They consulted with electricity utility companies about what sort of reactor they would like – something fusion researchers had never really done before. They called this dream machine LIFE, for laser inertial fusion energy.
The first thing to tackle was the laser. NIF’s laser, though a wonder, is totally unsuitable for an inertial fusion power plant. It’s a single monolithic device, prone to optical damage, and could only be fired a few times a day. The NIF team didn’t want to abandon neodymium glass lasers altogether – it was the technology that they knew and understood. But they could get rid of the temperamental and power-hungry xenon flashlamps that pump the laser glass full of energy. The ideal alternative would be solid-state light emitting diodes, similar to those used in LED TV screens and the latest generation of low-energy light bulbs. They are more efficient than flashlamps, power up more quickly and are less prone to damage. Electronics companies can make suitable diodes today but they are so expensive that they would make a laser power plant uneconomic. However the NIF researchers calculated that, like most electronic components, their price will go down rapidly and, by the time LIFE needs them, they will be affordable.
It also wouldn’t do to have LIFE relying on a single laser to drive the whole power plant. If any tiny thing went wrong the entire plant would have to be shut down for repairs. So instead of a single laser split into 192 beams, LIFE would have twice as many beams (384) with each produced by its own laser. The plan was for the lasers to be produced in a factory as self-contained units – essentially a box big enough to keep a torpedo in. The operators of the plant wouldn’t need to know anything about lasers; the units would be delivered by truck and the operators would just slot them into place and turn them on. The plant would have spares on site and if one laser failed it could be pulled out and be replaced without stopping energy production.
Livermore researchers also had a novel solution to one of the big questions of fusion reactor design: neutron damage. Nuclear engineers are working hard to find new structural materials for fusion reactors that can withstand a constant barrage of high-energy neutrons for years on end. But the Livermore team didn’t want to have to wait for new materials to be developed and tested. They opted for a simpler solution for LIFE: make the reaction chamber replaceable. In their design, the only thing that physically connects to the reaction chamber is the pipework for cooling fluid. After a couple of years this can be disconnected and the entire reaction chamber wheeled out on rails to an adjacent building, then a fresh chamber can be wheeled in. The old chamber would need a few months to ‘cool off’ so that its radioactivity drops to a safer level, then be dismantled and buried in shallow pits.
It was a bold plan and, because of its policy of relying on known technology and off-the-shelf components, the team calculated that, once ignition on NIF is achieved, they could build a prototype LIFE power plant in just twelve years.
Livermore wasn’t the only organisation thinking ahead to what will happen after ignition is achieved. The US Department of Energy and in particular its science chief Steven
Koonin realised that when that breakthrough came the White House, Congress, other organisations and the public would start asking questions, such as what has the US been doing in inertial fusion in recent years? And what is it going to do now to progress from scientific breakthrough to commercial power plant? The answer to the first question was: not very much. During the construction of NIF and afterwards, other research on inertial confinement fusion was starved of funding. The Rochester University lab got some money for its supporting role to NIF but research at the national laboratories and elsewhere was minimal. However that didn’t mean that those few researchers working in the field didn’t have ideas about what to do next.
Koonin was very familiar with NIF, having been drafted onto various panels over the years to assess it and other fusion projects. What Koonin needed now was a broad survey of the state of the whole field of inertial fusion research, so again the National Academy of Science was called on to investigate. The NAS assembled a panel of experts from universities, national labs and industry. Over the course of a year they visited many of the main facilities involved in inertial confinement fusion research and heard dozens of presentations. Their first port of call outside Washington was to Livermore where NIF researchers explained their plans for the LIFE power plant.
Next they visited the Sandia National Laboratory in Albuquerque, New Mexico. Researchers there had been working on inertial confinement fusion using, not lasers, but extremely powerful current pulses to crush a target magnetically. Their technique uses the pinch effect, the same phenomenon that Peter Thonemann stumbled upon in the 1940s and caused him to travel from Australia to Oxford to start building fusion reactors. The pinch effect causes a flowing electric current to be squeezed by its own magnetic field inwards towards its middle. Thonemann’s devices, along with all tokamaks, use the pinch effect to squeeze a flowing plasma, compressing and heating it. The researchers at Sandia use the pinch in a different way. They confine fusion fuel in a cylindrical metal can and then pass a huge current down the outer walls of the can. The pinch effect squeezes the walls of the can in towards the centre and so crushes the can. If the current pulse is big enough and fast enough then the crushed can compresses and heats the fuel inside enough to spark fusion.
Piece of the Sun : The Quest for Fusion Energy (9781468310412) Page 27