by In the heart of Provence, some of the brightest scientific minds on the planet are setting the stage for what is known as the world’s largest and most ambitious science experiment.
“It could be argued that we are building the most complex machine ever designed,” says Laban Coblentz.
The task at hand is to demonstrate the feasibility of harnessing nuclear fusion – the same reaction that powers our Sun and stars – on an industrial scale.
To do this, the world’s largest magnetic confinement chamber, or tokamak, is being built in southern France to generate clean energy.
The US, EU, Russia, China, India and South Korea formally signed the International Thermonuclear Experimental Reactor (ITER) project agreement in 2006 at the Elysée Palace in Paris.
More than 30 countries are now collaborating on the effort to build the experimental device, which is estimated to weigh 23,000 tons and withstand temperatures of up to 150 million °C when completed.
“In a way, this is like a national laboratory, a large research institute facility. But it is the convergence of the national laboratories, in fact, of 35 countries,” Coblentz, head of ITER communications, told Euronews Next.
How does nuclear fusion work?
Nuclear fusion is the process by which two light atomic nuclei combine to form one heavier one, generating a massive release of energy.
In the case of the Sun, hydrogen atoms are fused in its core by the enormous amount of gravitational pressure.
Meanwhile, here on Earth, two main methods of generating fusion are being explored.
“The first one, you may have heard at the National Ignition Facility in the US,” explained Coblentz.
“You take a tiny bit – the size of a pepper – of two types of hydrogen: deuterium and tritium. And you shoot a laser at them. So, you’re doing the same thing. You’re pushing on pressure as well. like putting heat with it and you get a burst of energy, E = mc². A small amount of matter is converted into energy”.
The ITER project is focused on the second possible way: magnetic confinement fusion.
“In this case, we have a very large chamber, 800 m³, and we add a very small amount of fuel -2 to 3 g of fuel, deuterium, and tritium – and we get it up to 150 million degrees through different heating systems. ,” said Laban.
“That is the temperature at which the velocity of these particles is so high that they come together and fuse instead of chasing each other with their positive charges. And when they combine, they release an alpha particle and release a neutron”.
In the tokamak, the charged particles are confined by a magnetic field, except for the highly energetic neutrons that escape and hit the wall of the chamber, transferring their heat and making way for the water running behind the wall that.
In theory, the resulting steam would harness energy to drive a turbine.
“This is, if you will, a successor to a long line of research devices,” explained Richard Pitts, head of ITER’s science division.
“The field has been investigating tokamak physics for about 70 years, since the first experiments were designed and built in Russia in the 1940s and 50s,” he said.
According to Pitts, the early tokamaks were small tabletop devices.
“Then, bit by bit, they get bigger and bigger and bigger because we know – from our work on the smaller devices, our scaling studies from small to large to large – that in order to get clean fusion power out of these things, we need to make one as big as this,” he said.
Advantages of fusion
Nuclear power plants have been around since the 1950s using a fission reaction, which splits the atom in a reactor, releasing huge amounts of energy in the process.
Fission has the clear advantage of being the established method that is already being tested, with over 400 nuclear fission reactors in operation around the world today.
But while nuclear disasters have been rare in history, the catastrophic meltdown of reactor 4 at Chernobyl in April 1986 is a stark reminder that they are not entirely risk-free.
In addition, fission reactors have to deal with the safe management of huge amounts of radioactive waste, which are usually buried deep underground in geological repositories.
In contrast, ITER notes that a fusion plant on a similar scale would generate power from a much smaller amount of chemical input, just a few grams of hydrogen.
“The safety effects are not even comparable,” Coblentz noted.
“You’ve only got 2 to 3 g of material. In addition, the material is used in a fusion plant, deuterium and tritium, and the material that comes out, non-radioactive helium and neutrons. So there is no something left there, so to speak, and the inventory of radioactive material is extremely tiny,” he said.
Blockade of the ITER project
The challenge with fusion, according to Coblentz, is that these nuclear reactors are extremely difficult to build.
“You try to build something up to 150 million steps. You try to do it to the scale that’s needed and so on. It’s just a difficult thing to do,” he said.
Certainly, the ITER project is struggling with the complexity of this gargantuan undertaking.
The original timeline for the ITER project set 2025 as the date for first plasma, with full commissioning of the system marked for 2035.
But there’s a changing timeline for system commissioning and a ballooning budget to match due to component backlogs and delays related to COVID-19.
The initial cost estimate for the project was €5 billion but has increased to over €20 billion.
“We’ve faced challenges simply because of the complexity and the multitude of similar materials, similar components in a similar machine,” explained Coblentz.
One notable setback involved misalignment of the welding surfaces of parts of the vacuum chamber manufactured in South Korea.
“The ones that came in where you’re welding together have enough inconsistencies in the edges that we have to redo those edges,” Coblentz said.
“It’s not rocket science in that particular case. It’s not even nuclear physics. It’s just machining and getting things to an incredible level of precision, which was difficult,” he said.
Coblentz says the project is currently undergoing a re-sequencing process, hoping to stick as close as possible to its 2035 goal of starting fusion operations.
“Instead of focusing on the dates we had before the first plasma, the first test of the machine in 2025, and then a series of four steps to first achieve fusion power in 2035, we will only do the first plasma to skip. make sure that test is done in a different way so that we can stick to that date as much as possible,” he said.
International cooperation
As far as international collaborations go, ITER is something of a unicorn in that it has withstood the geopolitical tensions between many of the nations involved in the project.
“Clearly these countries are not always ideologically aligned. If you look at the feature flags on the work site alphabetically, China flies next to Europe, Russia flies next to the United States, ” Coblentz noted.
“Regarding those countries making a 40-year commitment to work together, there was no certainty. There will never be certainty that there were not certain conflicts”.
Coblentz puts the relative health of the project down to the fact that nuclear fusion is a common dream passed down from generation to generation.
“That’s what brings that strength together. And that’s why he survived the current sanctions that Europe and others have on Russia in the current situation with Ukraine,” he said.
Climate change and clean energy
Given the scale of the challenge presented by climate change, it is little wonder that scientists are racing to find a carbon-free energy source to power our world.
But the abundant fusion energy supply is still a long way off, and even ITER admits that their project represents the long-term answer to energy concerns.
In response to the notion that fusion will come too late to help tackle the climate crisis in a meaningful way, Coblentz asserts that fusion power could play a role further into the future.
“If sea level rise is really as big as we start needing the energy consumption to move cities? If we start looking at energy challenges on that scale, the answer to your question is obviously,” said he.
“The longer we wait for the fusion to come, the more we need it. So the smart money is: get it here as fast as possible”.
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