In July 1992 Livermore came back with its proposal for the Nova upgrade. The laser would have eighteen beamlines, half in the existing Nova building and the other half in the old Shiva building next door. The light from each beamline would be split into sixteen beamlets and channelled into an upgraded Nova target chamber. The laser contained a number of technical innovations which aimed to save money as much as improve performance, such as main amplifiers that the light passes through several times, bounced back and forth by mirrors, so as to get the maximum amplification. The final beam energy would be between 1 and 2 megajoules and the facility would cost around $400 million. But political events in the wider world would soon prompt a rethink of those plans.
In the few years since Livermore had begun to plan this latest generation of lasers, the Eastern bloc had torn itself apart, the Berlin Wall had fallen and the Soviet Union itself had fractured into Russia and a handful of newly independent states. In the early 1990s the Russian economy was near to collapse and the old Cold War adversaries, worn down by decades of the nuclear arms race, were eager to talk about disarmament. One of the first items on the agenda was a comprehensive nuclear test ban, the prohibiting of all nuclear explosion tests on land, underground, in the sea, air or space. The first discussions of such a treaty began in 1991 and the following year the United States began a voluntary moratorium of testing which it has held to ever since. Without the ability to test weapons it would be impossible to design and build new ones, or even to check that existing ones were still working. The two main weapons laboratories – Los Alamos and Livermore – suddenly began to look like expensive luxuries and members of Congress started asking whether Livermore, in particular, was needed at all.
The national labs struggled to find new roles for themselves and sought to diversify into environmental research and green energy technologies. But they were given a big boost when Congress enacted a bill in 1994 that created the Stockpile Stewardship Program. The SSP was a scientific programme to understand the physics and chemistry of what happened to nuclear weapons as they aged so that measures could be taken to ensure they remained safe and reliable. This included refurbishing or remanufacturing components or whole weapons if necessary. The programme was also required to ‘maintain the science and engineering institutions needed to support the nation’s nuclear deterrent, now and in the future.’ This meant that the country needed to keep trained weapon designers working in its national labs so that they could design new weapons if required by emerging threats in the future and, theoretically, build them without using explosive testing. Top-flight scientists were not going to sit around in the labs keeping an eye on the slowly ageing stockpile of nuclear weapons; they needed some serious science to keep them busy, so the lab directors started looking around for major new facilities that could be built as part of the programme.
The government put around $4.5 billion per year into SSP, which was a lot less than it used to spend on nuclear testing before 1992 but was still a considerable sum. The directors of the national labs held a series of meetings to decide who would get what. Sandia, it was decided, would build the Microsystems and Engineering Sciences Applications (MESA) complex where the radiation-hardened electronic components of nuclear weapons could be designed, fabricated and tested. Los Alamos got the Dual-Axis Radiographic Hydrotest Facility (DARHT) in which conventional explosives are used to compress sections of plutonium as would happen during the implosion of a nuclear bomb. The facility uses powerful pulsed x-ray beams to take ultrafast pictures of these test implosions. For Livermore the meetings decided on a laser fusion facility with which weapon scientists could study tiny thermonuclear blasts and use the data to validate computer models of nuclear weapons. The Omega upgrade wasn’t sufficient for the weapons scientists’ requirements and so Livermore drew up a new plan: dubbed the National Ignition Facility (NIF), it brazenly carried one of its main objectives in its name.
With the weight of the SSP behind it, NIF seemed to have an unstoppable momentum. But its huge price tag of around $1 billion and its controversial dual role – fusion energy research and stockpile stewardship – immediately drew criticism. Those in the laser fusion field, including proponents of direct drive from Rochester and the Naval Research Laboratory, argued that it was too big a technological leap and was the wrong kind of machine to be a demonstrator for fusion energy. NIF was being designed to produce laser pulses with an energy of 1.8 megajoules – sixty times Nova’s energy. Laser experts feared that with that amount of energy moving through in ultra-short pulses the machine’s optics would suffer frequent damage, making the laser prohibitively expensive to operate. They were sceptical that such a huge machine could produce beams of sufficient smoothness to implode targets evenly. They saw indirect drive as a dead end because hohlraums made of heavy metals such as gold – which are destroyed in each shot – would be too expensive for a working power plant. And, they said, Nd:glass was never going to cut it as a driver for a fusion energy plant because it was too inefficient at converting electrical energy into beam energy and it couldn’t do the rapid-fire operation needed to make a plant commercially viable. Why then, they asked, make such a huge investment in a laser that won’t take the technology of fusion energy forward?
Many in the stockpile stewardship field didn’t like it either. NIF had rapidly grown to become the behemoth of the SSP and scientists at the other national labs and elsewhere attacked it for taking up so much SSP funding while having little real impact on the science of maintaining reliable nuclear weapons. There was a widespread suspicion that NIF’s real role was either to surreptitiously allow the designing of new nuclear weapons or that it was just an expensive play thing to keep weapons designers busy in case they are needed in the future.
Despite the criticism, DoE pushed ahead with NIF, asking Livermore for a conceptual design. Although this isn’t as detailed as an engineering design, for NIF it ran to twenty-seven volumes, a total of 7,000 pages. But the next phase, an engineering design, was put on hold in May 1994 when the then Energy Secretary, Hazel O’Leary, received a five-page memo from an anti-nuclear group called Tri-Valley Citizens Against a Radioactive Environment (Tri-Valley CAREs) which argued that any use of NIF to design new weapons could jeopardise negotiations going on at that time to renew the Nuclear Non-Proliferation Treaty. O’Leary allowed the engineering design to go ahead later in the year but she realised that NIF had better have firm scientific justification before proceeding to construction, so she asked the National Academy of Sciences to set up an inertial confinement fusion advisory committee to vet the NIF design and assess its readiness for construction. Steven Koonin of Caltech, who had chaired the 1989-90 laser fusion panel, was chosen to lead this one too.
The Natural Resources Defense Council (NRDC), an advocacy group in Washington, DC, and a vociferous opponent of NIF, accused DoE of biasing the committee. According to NRDC, several of the committee members were paid consultants to Livermore, some were awaiting decisions on bids for DoE contracts, almost all had a personal or institutional connection with DoE, and a majority had previously stated positions in favour of NIF. The committee’s report, which everyone expected to approve NIF’s construction, was due to be released in early March 1997, but then NRDC along with Tri-Valley CAREs and a group called the Western States Legal Foundation took the matter to court. They invoked a clause of the Federal Advisory Committee Act of 1972 which stipulates that such committees must conduct their business in public. Koonin had presided over some closed sessions of the committee, in contravention of the Act, so NRDC and the other two bodies were able to win an injunction barring DoE from making use of the report or spending any more money on it.
While deliberation of that case continued, NRDC and thirty-eight other environmental groups sought another injunction in May to prevent the start of construction of NIF, claiming that DoE had failed to comply with environmental standards when planning the facility. An official groundbreaking ceremony went ahead on 29th May although
Vice President Al Gore did not attend because of the lawsuit. The official start of construction, scheduled for 5th June, was put on hold. Legal arguments continued until August when the judge in Washington’s district court turned down NRDC’s environmental injunction. DoE still didn’t have the seal of approval of Koonin’s advisory committee but it decided to go ahead without it and construction of NIF began.
This was how NIF came to be the centrepiece of the US inertial confinement fusion programme. Rochester built its upgraded Omega laser, but much of the work it did was in preparation for NIF. Some inertial confinement projects continued on a small scale at other labs – Los Alamos, Sandia, the Naval Research Lab – but these were sideshows compared to NIF. As construction began, DoE estimated NIF would cost $1.1 billion to build plus another $1 billion for operation and be finished by 2002 – like Livermore’s computer simulations, this proved to be wildly optimistic.
Everything seemed to go smoothly at first, apart from a four-day hiatus in construction when crews found the 16,000-year-old bones of a mammoth on the site. A high point came when NIF’s target chamber was hoisted into place in June 1999. A steel sphere 10m across and weighing 130 tonnes, the chamber required one of the world’s largest cranes to lift it. The Secretary of Energy Bill Richardson was present at the ceremony that followed and he announced that the project was ‘on cost and on schedule.’ He said the same thing in Congress when questioned about progress. Then everything seemed to go wrong at once.
First Michael Campbell, the long-time Livermore physicist who was leading the project, stepped down in August after an anonymous whistleblower told Livermore managers that he had never finished the PhD from Princeton University that he claimed to have. Then only days later it emerged that the project was suffering from numerous technical problems and was, in fact, a year behind schedule and $200 million over budget. Worse still, the project’s leaders had hidden this information from Richardson, which had led him to give incorrect information to Congress. A number of staff were fired or demoted and there were financial penalties for the Livermore director and the University of California, which manages the lab. Numerous investigations were launched to find out what had gone wrong, including one by the influential Government Accountability Office, the investigative arm of Congress. A Congressional appropriations committee directed DoE to develop a new schedule and cost estimate for NIF and to present it to Congress by 1st June, 2000 or prepare to terminate the project. Livermore’s freedom to manage the project as it saw fit with little scrutiny – a side-effect of its role as a weapons lab – was at an end as NIF became one of the most closely monitored projects in the history of science.
NIF’s technical troubles had started hundreds of miles away at Sandia National Laboratory in New Mexico. With its expertise in pulsed power experiments, Sandia was contracted to produce 200 huge capacitors – stores of electric charge – which would be used to power the flashlamps that pump NIF’s laser amplifiers. But during tests the material of the capacitor was vaporising and the pressure inside the device caused its metal cladding to fly off like shrapnel. The capacitors had to be redesigned with a centimetre-thick steel shell on the outside and pressure-escape doors at the bottom. The companies that were making the neodymium-doped glass for the amplifiers had trouble keeping out impurities, which led to more delays. Another constant bugbear was dust: if there was any dust on the surfaces of the optics when beams passed through it was likely to ignite and damage the surface. But keeping the levels of dust down in a building the size of a football stadium proved to be a complete nightmare. The building itself turned out to be a problem because it was built before the design of the laser system had been finalised, leading to a tight fit that left little room for maintenance.
DoE reported back to Congress on 1st June, 2000 with an ‘interim report’ that did not detail cost or schedules, but it soon emerged that it was estimating a final cost of $3.3 billion and completion in 2008. The Government Accountability Office submitted its report in August, concluding that ‘NIF’s cost increases and schedule delays were caused by a combination of poor Lawrence Livermore management and inadequate DoE oversight.’ Its estimate of NIF’s total cost was nearer to $4 billion. Energy Secretary Richardson said that he didn’t want to ask Congress for more money for NIF so would find the cash from elsewhere. Fearing that some of their facilities might be cut back to pay for NIF, the other weapons labs suggested cutting back on the number of NIF beamlines to save money. But somehow the wounded NIF survived. It limped on, heavily scrutinised, but without much further incident, until 2009 when it was declared complete, seven years late and having cost almost twice the original estimate.
Accident-prone it may have been, but NIF’s many opponents failed to stop it being built or to scale it back. With the backing of weapons designers and a measure of institutional inertia, it made it to the finish line. All that remained now for the world’s biggest laser was to see if it could achieve ignition.
One of two laser bays at the National Ignition Facility. Here beams are amplified in power before converging on a fusion target.
(Courtesy of Lawrence Livermore National Laboratory)
CHAPTER 7
One Big Machine
IN MOST SCIENCES YOU BUILD MACHINES TO ALLOW YOU TO DO experiments. In fusion, the machine is the experiment. You build it to see if it will work and how it works. Because fusion machines take such a long time to build, fusion scientists are always looking one, two or more machines into the future: while they’re building one, they’re always planning more. So it was in the late 1970s, when the construction of JET and TFTR was only just beginning, that many researchers were beginning to think about what was to come next.
The route to fusion energy that had been mapped out earlier in the decade had three stages. First was a demonstration of the scientific feasibility of fusion, in other words a gain greater than 1, and the big tokamaks being built in Princeton, Culham and Naka were expected to take care of that. Next would be technical feasibility, a machine that would produce large amounts of energy while testing some of the technologies that would be needed in a fusion power station, such as superconducting magnets, a system for extracting heat to raise steam, and a method for breeding tritium for fuel. The final stage was commercial feasibility – a prototype power reactor.
So while the three big machines still existed only on paper, some of the more far-sighted planners were already thinking about the even bigger machine, the ‘engineering reactor’ that would come after. One of them was Russian theorist Evgeniy Velikhov. Velikhov was a rising star in the Kurchatov Institute’s fusion department in the 1960s where he teamed up with fellow young theorists Roald Sagdeev and Aleksandr Vedenov – soon dubbed by colleagues as the ‘holy trinity.’ Plasma theory was too narrow a field to contain his talents and he later branched into lasers as well as computers and automation. He was also a skilful political operator – he knew how to play the Soviet system of patronage and political influence. His star was rising so fast that in 1973, at the age of just 38, he took over the reins of Russia’s fusion programme following the death of Lev Artsimovich. In 1974 he was made a full member of the Soviet Academy of Sciences and three years later was elected its vice president.
Before his death, Artsimovich sent Velikhov to represent the Kurchatov Institute in discussions at the International Atomic Energy Agency (IAEA) in Vienna. Ever since the 1958 Geneva conference, fusion scientists had maintained a constant dialogue between East and West. The IAEA organised its regular fusion conferences which all nations could attend. There were visits to each other’s labs and exchanges of information but relations stopped short of any formal cross-border collaboration apart from that of Euratom. That started to change when Velikhov, along with Amasa Bishop of the US Atomic Energy Commission and IAEA chief Sigvard Eklund, formed the International Fusion Research Council (IFRC) in 1971 to advise the agency in its efforts to coordinate worldwide fusion research. Although the IFRC was simply a group of advisers,
Velikhov hoped it would prove influential in moving fusion research towards closer collaboration. He already suspected that an engineering reactor might be so large as to be beyond the capabilities of a single country’s fusion research programme.
Velikhov was not the only one thinking along these lines. Within all the fusion programmes, researchers were beginning to realise that as soon as they had cracked the problem of getting a plasma to burn they would have to learn how to handle the neutrons, extract heat and breed tritium. One of those was David Rose, an engineer who was hired by the Massachusetts Institute of Technology in 1958 when it set up its Department of Nuclear Engineering. In the late 1960s he carried out a detailed study of how energy in a fusion reactor would be exchanged between different types of particles – electrons, deuterium and tritium ions, and alpha particles – and how you would inject fuel into the plasma and remove helium exhaust. His calculations suggested that a fusion reactor would be economically viable, but it would need to be big. In 1969 he co-organised a meeting at Culham, the first meeting to consider the engineering issues of a fusion reactor, and this encouraged many more engineers to get involved.
As the 1970s progressed and tokamaks grew bigger and performed better, the need for engineering solutions became more pressing. In 1977 Rose invited senior engineers from different countries to a meeting to discuss how they might better work together. The group weren’t sure how to form an international collaboration but concluded it should probably be organised by the IAEA. It turned out the IAEA was already moving in that direction. The agency’s chief, Eklund, asked the IFRC for suggestions of how the IAEA could take a more active role in fusion research and Velikhov quickly stepped up with a plan he had already worked out: an international collaboration to design a reactor with the express purpose of testing the technology necessary for a commercial reactor.
Piece of the Sun : The Quest for Fusion Energy (9781468310412) Page 22