The continuing quest to use nuclear fusion for the world’s energy demand: CORDIS attends the 11th World Conference of Science Journalists
What weighs 23 000 tonnes and has a potential temperature of 150 million °C? Literally, it’s the new star of the energy world, the ITER reactor.
Dr Bernard Bigot, ITER Organization Director-General (DG), sits alone on the stage, the star machine backdrop rising behind him at the site in Provence, France. He was formerly director of the French Commission for Atomic Energy, the CEA, and has been leading the world’s most expensive project ITER as a world expert on nuclear fusion since 2015.
ITER is an international collaboration of the EU, China, India, Japan, Korea, Russia and the United States, half the population of the world. All the members are involved in the building of the reactor, the culmination of decades of research and design.
Ready to react
The ITER machine, a tokamak, will fuse light atoms into heavier ones, like the reactions at the core of the Sun and stars. The fuel is hydrogen, specifically ‘heavy’ atoms of the element: deuterium and tritium.
Dr Bigot exclaims: “One gramme of the fuel will generate as much energy as 8 tonnes of fossil fuels. We will go to a higher temperature than in the Sun with more acceleration and more energy expended.” Little wonder then that nuclear fusion is heralded as the saviour against global warming and pollution associated with burning carbon-based material from plant and animal remains.
Three generations of physicists have worked to make the ITER Tokamak a reality. Previous tokamaks were too cool so there was not enough plasma formation and not enough (atomic) collisions. The timeline DG Bigot outlines seems a long way off, but: “In March 2020, the reactor will be ready to operate … the first plasma where fusion will occur will be formed in 2025 … and in 2035, the temperature at the plasma core with self-sustaining plasma will be 150 million °C,” he declares passionately.
Statistics out of this world and more to come from the unknown
There will be a total of 100 000 km niobium wire used in the structure, enough to wrap around the Earth twice. Each of the coils is 20 m long and produced to an accuracy of 0.2 mm! Referring to the massive collaboration in one project: “One country on its own couldn’t manage this,” Dr Bigot declares with emotion.
Aware that there are still many unknowns for nuclear fusion, Dr Bigot states openly that there will be unexpected events in the reactor. Just one example: “High energy particles are produced in the fusion reaction. The material used to absorb this energy, niobium, may not be good enough, so we possibly have to invent new materials. We are inventing new materials,” he emphasises.
Dr Bigot sums up: “My dream is that we will do the best we can so fusion will work and it will offer some surprises … We will fulfil the expectations of the ITER project and make fusion a reality.”