The European nuclear fusion reactor risks starting lame

The European nuclear fusion reactor risks starting lame

In the south of France, Iter is nearing completion. When activated in 2035, the International thermonuclear experimental reactor is set to become the flagship of nuclear fusion, as well as the largest device of its kind ever built.

Inside a reaction chamber in the shape of a donut, called tokamak, two types of hydrogen, deuterium and tritium, will collide so that when they merge, they create a plasma hotter than the sun's surface, producing enough clean energy to power tens of thousands of homes - an unlimited source of electricity taken straight from science fiction.

Or at least, that's the plan. The problem is that when Iter is ready, there may not be enough fuel left to run it.

Like many of the major experimental nuclear fusion reactors, Iter also depends on a constant supply of deuterium and tritium for its experiments. While deuterium can be extracted from seawater, tritium, a radioactive isotope of hydrogen, is incredibly rare.

Problems with tritium Levels of tritium in the atmosphere peaked over the years Sixty, before the ban on testing nuclear weapons. According to the latest estimates, there are currently less than twenty kilos of tritium on Earth. As Iter's project lags years on schedule and overshoots the budget by several billion, the best sources of tritium to power the device and other experimental fusion reactors are slowly disappearing.

WiredLeaks, how to send us an anonymous report Currently, the tritium used in nuclear fusion experiments such as those conducted by Iter and Jet - a smaller tokamak in the UK - comes from a very specific type of nuclear fission reactor , called heavy water reactor. Many of these reactors, however, are nearing the end of their life cycle, and fewer than thirty remain in operation worldwide to date: twenty in Canada, four in South Korea and two in Romania, each of which produces about 100 grams of tritium per year (India plans to build more, but it is unlikely to make its tritium available to fusion researchers).

This solution is not viable in the long run: the purpose of nuclear fusion is to provide a cleaner and safer alternative to traditional nuclear fission energy. "Using 'dirty' fission reactors to power clean fusion reactors would be nonsense," explains Ernesto Mazzucato, a former physicist who has openly criticized Iter and nuclear fusion in general, despite spending much of his working life studying i tokamaks.

The second problem is that tritium deteriorates rapidly. The half-life of the element is 12.3 years, which means that when Iter is ready to start deuterium-tritium operations (coincidentally, in about 12.3 years), half of the tritium available today will have decayed into helium-3. After the ignition of Iter, the problem is destined to worsen with the development of other deuterium-tritium devices (D-T ).

These two forces have helped transform tritium from an unwanted by-product of nuclear fission to be carefully disposed of into, by some estimates, the most expensive substance on Earth. Tritium costs $ 30,000 per gram mo and it is estimated that a functioning fusion reactor will need up to two hundred kilograms per year of the element. As if that weren't enough, tritium is also coveted by nuclear weapons programs, because it helps make bombs more powerful; however, the military tends to produce it themselves, since Canada, which holds most of the world's production capacity for tritium, refuses to sell it for non-peaceful purposes.

In 1999, Paul Rutherford, a researcher at Princeton's Plasma Physics Laboratory, published an article predicting the problem and describing the so-called "tritium window," a favorable period in which tritium supplies would peak before declining as reactors shut down heavy water. Right now we are inside this window, but Iter - whose construction is almost a decade behind schedule - is not ready to exploit it. "If Iter had started producing plasma with deuterium and tritium about three years ago, as predicted, it would have been fine," explains Scott Willms, head of Iter's fuel cycle division. or not right now ".

Making tritium Scientists have been aware of this potential obstacle for decades and have come up with a way around it: a plan to use nuclear fusion reactors to" generate "the tritium, so as to generate fuel at the same time it is burned. The project envisages surrounding the fusion reactor with a lithium-6 "mantle"; when a neutron escapes the reactor and hits a lithium-6 molecule, tritium should be generated which can be extracted and fed back into the reaction.

The project to generate tritium was initially to be tested under Iter, but when the costs of the project have soared from the initial six billion dollars to more than twenty-five billion, it has been set aside. Willms' job within Iter is to manage small-scale tests. Instead of a lithium mantle surrounding the fusion reaction, Iter will use lithium samples inserted into "gates" positioned around the tokamak.

However, Willms himself admits that the technology is far from ready and that we will have to wait for the next generation of reactors to test the reproduction of tritium on a large scale, when according to some it may be too late. "After 2035 we will have to build a new machine that will take another twenty or thirty years to test a crucial function like tritium production. How can we block global warming with fusion reactors if we are not ready before the end of this. century? ", underlines Mazzucato.

There are other techniques to create tritium, but they are too expensive to be used in the necessary quantities. In an ideal world, there would be a more ambitious program to develop the technology to reproduce tritium in parallel with Iter, Willms explains, so that when the project's fusion reactor is perfected there is still a source of fuel to make it work. "We don't want to build the car and run out of gas," adds Willms.

The tritium problem is fueling skepticism about Iter and D-T fusion projects in general. Initially, deuterium and tritium were chosen because they fuse at a relatively low temperature: they are the easiest elements to work with, at one time any other option seemed impossible.

The alternatives See more Choose the newsletters you want to receive and subscribe! Weekly news and commentary on conflicts in the digital world, sustainability or gender equality. The best of innovation every day. These are our new newsletters: innovation just a click away.

Arrow Today, however, with the help of magnets controlled by artificial intelligence (Ai), which help to confine the fusion reaction, and the advances in materials science, some companies are exploring alternatives. Tae Technologies, a California-based company, is looking to build a fusion reactor that uses hydrogen and boron that the company says will be a cleaner and more practical alternative to D-T fusion.

The goal is to achieve a positive energy balance - in which a fusion reaction creates more energy than it consumes - by 2025. Boron can be extracted from seawater by the ton and has the advantage of not irradiating the device, as it does. the D-T merger. Tae Technologies CEO Michl Binderbauer argues that this is a commercially more viable way to obtain fusion energy.

But the fusion community is still pinning its hopes on Iter, despite the potential problems supply of its essential fuel. "Fusion is really, really difficult, and anything other than deuterium-tritium will be a hundred times harder - explains Willms -. In a century, maybe we can talk about something else."

This article originally appeared on UK.

Powered by Blogger.