The US National Ignition Facility (NIF), seen inside here in July 2008, allegedly achieved a fusion reaction that produces more energy than was put into it – Copyright AFP/Jonathan NACKSTRAND File
The US Department of Energy’s nuclear fusion laboratory says there will be a “scientific breakthrough” announced Tuesday, as media reports scientists finally passed a major milestone for the technology: getting more energy than we Was inverted.
The announcement has the scientific community in an uproar, as nuclear fusion is considered by some to be the energy of the future, particularly because it produces no greenhouse gases, leaves little waste and has no risk of nuclear accidents.
Here’s an update on how nuclear fusion works, what projects are underway, and estimates for when they might be completed:
– Energy from the stars –
Fusion differs from fission, the technique currently used in nuclear power plants, by fusing two atomic nuclei instead of splitting one.
In fact, fusion is the process that powers the sun.
Two lightweight hydrogen atoms, when colliding at very high speeds, fuse into a heavier element, helium, releasing energy in the process.
“Controlling the power source of the stars is the greatest technological challenge humanity has ever undertaken,” physicist Arthur Turrell, author of “The Star Builders,” tweeted.
– Two different methods –
Producing fusion reactions on Earth is only possible by heating matter to extremely high temperatures: more than 100 million degrees Celsius (180 million Fahrenheit).
“So we have to find ways to isolate this extremely hot matter from anything that could cool it down. This is the containment problem,” Erik Lefebvre, project manager at France’s Atomic Energy Commission (CEA) told AFP.
One method is to “confine” the fusion reaction with magnets.
In a huge donut-shaped reactor, light isotopes of hydrogen (deuterium and tritium) are heated until they reach the state of plasma, a very low-density gas.
The magnets confine the swirling plasma gas, preventing it from coming into contact with the chamber walls, while the atoms collide and begin to fuse.
This is the type of reactor used in the large international project known as ITER, currently under construction in France, as well as the Joint European Torus (JET) near Oxford, England.
A second method is inertial confinement fusion, in which high-energy lasers are simultaneously directed at a thimble-sized cylinder containing the hydrogen.
This technique is used by the French Laser Megajoule (LMJ) and the world’s most advanced fusion project, the California-based National Ignition Facility (NIF).
Inertial confinement is used to demonstrate the physical principles of fusion, while magnetic confinement seeks to mimic future industrial-scale reactors.
– Status of the investigation –
For decades, scientists have tried to achieve what is known as a “net energy gain”—that is, the fusion reaction produces more energy than is needed to activate it.
According to reports in the Financial Times and the Washington Post, that will be the “scientific breakthrough” announced Tuesday by the NIF.
But Lefebvre cautions that “there is still a long way to go” before “an industrial-scale demonstration that is commercially viable.”
He says that such a project will take another 20 to 30 years to complete.
To get there, the researchers must first increase the efficiency of the lasers and reproduce the experiment more frequently.
– Fusion Benefits –
The reported success of the NIF has generated great enthusiasm in the scientific community, which hopes that the technology can be a game changer for global energy production.
Unlike fission, fusion carries no risk of nuclear accidents.
“If some lasers are missing and they don’t fire at the right time, or if the confinement of the plasma by the magnetic field…isn’t perfect,” the reaction will simply stop, Lefebvre says.
Nuclear fusion also produces much less radioactive waste than today’s power plants, and above all, it does not emit greenhouse gases.
“It’s a totally carbon-free source of energy, generates very little waste and is inherently extremely safe,” according to Lefebvre, who says fusion could be “a future solution to the world’s energy problems.”
Regardless of Tuesday’s announcement, however, the technology is still some way from producing power on an industrial scale and therefore cannot be relied on as an immediate solution to the climate crisis.