US scientists take key step toward unlimited, clean energy

A technician at the Lawrence Livermore National Laboratory's National Ignition Center. / LLNL

Science | Energy

They have achieved for the first time that in a nuclear fusion more energy is generated than the amount invested to cause the reaction

American scientists have made a breakthrough on the long road to unlimited clean energy. According to 'Financial Times', a nuclear fusion experiment carried out at the Lawrence Livermore National Laboratory (LLNL) has generated more energy than that used to cause the reaction, which is known as net gain. Nothing like this had ever been achieved.

"If confirmed, we are witnessing a historic moment," plasma physicist Arthur Turrell of the Imperial University of London told the British newspaper. The United States Department of Energy has confirmed to the 'Financial Times' that the Secretary of Energy, Jennifer Granholm, and the Undersecretary for Nuclear Safety, Jill Hruby, will announce this Tuesday in Washington "an important scientific advance" at the National Ignition Center of the LLNL,

Nuclear fusion is the reaction that takes place in the heart of stars, where, at temperatures of millions of degrees, two nuclei of light atoms unite to form a heavier one, releasing a large amount of energy in the process. This is what happens in the Sun. There, the fusions of hydrogen nuclei give rise to helium nuclei and that generates light and heat thanks to which we live. Our star is a gigantic fusion reactor that consumes 620 million metric tons of hydrogen per second.

Unlike nuclear fission, which is based on breaking a heavy atom into lighter ones and is used to produce electricity in nuclear power plants, fusion does not leave radioactive residues and, furthermore, its fuel, hydrogen, is unlimited. That is why scientists have been chasing it since the middle of the last century. It is an unlimited and clean source of energy, without greenhouse gas emissions either, which has the major drawback that it requires very high temperatures for the fuel –hydrogen– to become plasma and confine it with very powerful magnets or lasers so that its nuclei they merge.

"Great scientific milestone"

The LLNL reaction took place on December 5 and "achieved a net energy of 2.5 megajoules with a 2.1 megajoule laser and, according to some sources, the possible achievement of up to 3 megajoules is being analyzed," explained José Manuel. Perlado, Emeritus Professor of Nuclear Physics and President of the Guillermo Velarde Nuclear Physics Institute of the Madrid Polytechnic University, to Science Media Center Spain. "This is a huge step forward in believing that this can indeed be the massive, concentrated high-density source of energy that humanity needs."

«The experimental results obtained at the National Ignition Center are of great scientific importance as they achieve for the first time an amplification of the nuclear fusion energy greater than unity. This is a great scientific milestone”, Carlos Hidalgo, director of the National Fusion Laboratory of the Center for Energy, Environmental and Technological Research (Ciemat), told SMC Spain.

The advance that is expected to be announced this Tuesday is very important, but it does not mean that fusion energy is just around the corner, but rather decades away, and it will require continuing to invest billions of euros in projects such as the Experimental Thermonuclear Reactor International (ITER). Always with an eye on a horizon of clean and unlimited energy.