“We are just a few decades away” from nuclear fusion becoming the clean and inexhaustible energy that will change the world, said yesterday Kim Budil, physicist and director of the Lawrence Livermore National Laboratory (LLNL), after it became public that American scientists have managed to generate energy like stars do. Officials from the Department of Energy (DOE), the National Nuclear Security Administration and the LLNL announced in Washington that on December 5, a nuclear fusion was caused in a laboratory in which, for the first time, the energy produced was more than the energy invested. to achieve the reaction, which is known as net profit. An advance for which they spared no adjectives.
“This is a historic achievement for researchers and staff at the National Ignition Facility (NIF), who have dedicated their careers to seeing fusion ignition become a reality, and this milestone will undoubtedly trigger even more discoveries,” said Jennifer Granholm, US Secretary of Energy. “This astonishing scientific advance puts us on the precipice of a future that will no longer depend on fossil fuels, but on new clean fusion energy,” said Democrat Charles Schumer, Senate Majority Leader.
Merge vs Break
Nuclear fusion is the reaction that takes place in the heart of stars, where, at millions of degrees and under enormous pressure, two nuclei of light atoms join together to form a heavier one and a large amount of energy is released in the process. . The Sun is a fusion reactor that consumes 620 million metric tons of hydrogen per second, converting it into helium and generating in the process the light and heat with which we live.
Unlike fission, which is based on breaking heavy atoms and which produces electricity in nuclear power plants, fusion does not leave radioactive waste and, furthermore, its fuel, hydrogen, is unlimited. That’s why scientists have been pursuing it since the middle of the last century. It is the dream of inexhaustible and clean energy, without greenhouse gas emissions, but it requires very high temperatures for the fuel to become plasma and to confine it with very powerful magnets or lasers so that its nuclei fuse.
The NIF is a facility of the LLNL in whose construction the United States has invested 3.5 billion dollars. The December 5 experiment exceeded the fusion threshold by supplying 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of energy produced, generating for the first time more than was expended in the process. To achieve this, the scientists fired 192 laser beams at a peppercorn-sized capsule containing hydrogen atoms to heat them, compress them and fuse them. The laser used is so powerful that it can heat the capsule to 100 million degrees, compared to 15 million degrees at the center of the Sun, and compress it more than 100 billion times more than the Earth’s atmosphere. Obtaining more energy than consumed is a milestone that opens the doors to obtaining the holy grail of clean energy in the near future.
Many scientific and technological advances are still necessary to achieve a simple and affordable nuclear fusion that moves the world like fossil fuels do now. Currently, the NIF lasers can only fire a few times a day, when a commercial fusion plant would require at least ten firings per second. «We have had theoretical knowledge about fusion for more than a century, but the path from knowledge to practice can be long and arduous. Today’s milestone demonstrates what we can do with perseverance,” said Arati Prabhakar, senior advisor to the US president for Science and Technology, and director of the White House Office of Science and Technology Policy, yesterday.
“Achieving fusion ignition in the laboratory is one of the most important scientific challenges ever addressed by Humanity, and achieving it is a triumph of science, engineering and, above all, of people,” highlighted the director of the LLNL. Budil recalled that scientists have been pursuing this energy source for 60 years. Commercial use is “probably a matter of a few decades,” she said. And she pointed out that it won’t be six or five before it becomes a reality, alluding to the idea that nuclear fusion is an impossible thing that is always fifty years in the future, like sending the first humans to Mars.