I heard information on TV5 on French television that disturbed me quite a bit. I summarize: “This is it! We have finally succeeded in nuclear fusion and in 10 years, 20 at the most, we will no longer need oil, conventional nuclear power plants, etc. This new energy will replace all the others. ” Either the info was very optimistic (which I suspect) or it is true. Where are we exactly?
Francoise Chesnay
You are right to moderate your optimism. We would not advise Hydro-Quebec to start dismantling its dams right away, let’s say …
It is indisputable that the promises of nuclear fusion are immense.
“We are dealing with the Holy Grail and it is true that it would provide unlimited energy forever with an“ inexhaustible ”fuel [l’eau !] accessible to all countries. But to talk about all this in the next 10 or 20 years is illusory, in my opinion, ”says Émile Knystautas, professor in the engineering physics department at Laval University.
Let us first clarify things. In traditional nuclear power plants, large atoms like uranium are broken into smaller ones to produce energy in a process called nuclear fission. Fusion aims the opposite: to merge hydrogen atoms, the lightest that exist, to transform them into helium. It is the reaction that powers stars like the Sun and it releases massive amounts of energy. The other advantage is that such plants would produce virtually no greenhouse gases or nuclear waste.
The problem is, it’s anything but easy to do. To force the hydrogen atoms to combine, we must create a plasma, the fourth state of matter after solid, liquid and gas. We then have to heat this plasma to around 100 million degrees Celsius … without destroying everything around it. Since no material can contain such a plasma, it must be kept in place with very strong magnetic fields. Another approach uses lasers instead.
China, the European Union, the United States, Japan, India and Korea have come together to try to apply the recipe in a reactor called ITER, built in the south of France. Budgets are constantly being revised upwards and deadlines pushed back.
However, it is true that interesting progress has been made recently. As recently as this week, a Chinese team announced that it had kept plasma at 70 million degrees Celsius for more than 17 minutes – a record. Another sign that things are progressing: the private sector is jumping into the boat.
According to the new Fusion Industry Association, at least 35 companies are chasing the dream of nuclear fusion. Commonwealth Fusion Systems, an MIT company, recently announced that it had raised a colossal $ 1.8 billion from various investors, including Bill Gates and Google.
One of the challenges is to succeed in producing more energy than is supplied to the system. “We’re almost there, depending on the criteria we adopt and who we talk to,” says Professor Knystautas. But this is far from the end of the story.
Another milestone will be reaching what is called the ignition threshold, the point where the reaction can sustain itself. We’re not there yet. Mr. Knystautas also recalls that all the reactors under study in the world are experimental, and not power plants designed to supply the electricity grid. Significant engineering challenges will arise during the construction of the power plants, in particular because the plasma gradually destroys any metallic surface.
“The problem with nuclear fusion, as with other areas of science, is that scientists fail to control the message and are often preceded by a shock wave of publicity which then leads to disillusionment,” indicates Émile Knystautas. I am very optimistic about all the research that is being done on this subject. But not on the illusory schedule that we often hear about. ”