Nuclear fusion is an attempt to replicate the Sun's processes on Earth. It is a highly efficient and very clean source of energy. Until recently, achieving this kind of energy seemed like the stuff of science fiction, but it seems that the dream of emulating solar energy in a controlled space is getting closer and closer. If realised, the fusion of hydrogen atoms would become a clean and inexhaustible energy source capable of powering the entire world. We could eliminate fossil fuels and nuclear fission, a major step towards halting climate change. And all this without the need, unlike renewable energies, to rely on external factors such as solar radiation, wind or water power.
The race for nuclear fusion is led by researchers at the Lawrence Livermore National Laboratory (California), at the National Ignition Facility (NIF), who have managed to reproduce almost the full potential of the Sun's energy on Earth in a hydrogen particle for a fraction of a second. This is a "historic breakthrough" that offers hope for the development of a new source of clean and inexhaustible energy for humanity.
The NIF facility is not intended as a power plant, but as an experiment to find the key to the nuclear fusion that everyone is currently pursuing. Although the energy lasted only a very short time, around 100 billionths of a second, the researchers were optimistic that it was a valid starting point for their research, which is all about exploring fusion ignition. In other words, creating more energy than is currently being used. The scientists also explained that, after several experiments, they were able to achieve a large amount of energy from fusion. The team launched around 200 laser beams at a tiny point to generate a super burst of energy. A record that puts us almost at the tipping point for getting the nuclear fusion that powers stars off the ground.
"This breakthrough puts researchers on the threshold of inertial fusion ignition, a major goal of NIF, and opens access to a new experimental regime," say the authors, who indicate that the energy unleashed by this test would be equivalent to 10% of the 170 quadrillion watts of sunlight that bathes the Earth's surface. 2And all the fusion energy emanated from a hot spot the width of a human hair," says Mark Herrmann, deputy director of Livermore's programme.
Despite the great results obtained during the research, many experts say that the results obtained so far deserve to be reviewed more cautiously. For the co-director of the same centre in London, Jeremy Chittenden, "turning this concept into a renewable source of electricity is likely to be a long process and will involve overcoming significant technical challenges".
Nuclear fusion is a specific type of nuclear reaction. It is the process by which, for example, the Sun releases energy and extreme temperatures of several million degrees Celsius melt the atomic nuclei of hydrogen isotopes: deuterium and tritium, also known as heavy hydrogen and hydrogen-3, respectively. This fusion produces helium, a neutron and an enormous amount of energy sufficient for solar fusion to never cease.
The fission of uranium and plutonium in conventional nuclear power plants produces a multitude of radioactive products. Some of these can be converted into new fuels, but in the end there is always radioactive waste. These substances must be stored for thousands or hundreds of thousands of years in deep geological areas. In nuclear fusion, by contrast, the only radioactive product is helium, a noble gas. Another great advantage is that the fusion reaction is extinguished if no new fuel is added. There is no chain reaction as in conventional nuclear power plants. It is therefore impossible for the fusion reactor to run out of control. However, fusion reactions have proven difficult to control and, to date, no experiment has succeeded in producing more energy than has been invested to make the reaction work and sustain it over time, leading to the desired 'ignition'.
Although the growth of renewables will increase, many argue that renewables alone cannot sustain the world's enormous energy consumption. Meanwhile, scientific experiments like this one aim to produce safe, clean and unlimited energy on a large scale by means of nuclear fusion. Despite the obvious success of the test, this reactor does not serve as a model for the fusion power plants of the future, as its lasers can only fire once a day and a power plant needs constant production.
Other projects, such as the International Thermonuclear Experimental Reactor (ITER), a programme involving China, the European Union, Japan, South Korea, Russia and the United States, are moving in this direction to prove that this energy can be commercially viable. This reactor, which is already under construction in the south of France, will begin its first tests in the next few years.
Private initiatives are more optimistic. Today, some twenty European, American and Canadian start-ups have launched energy projects that aim to make the dream of nuclear fusion energy a reality. In a world with an ever-growing population and scarce resources, this energy source is the only viable option to tackle environmental and supply problems.