California’s nuclear fusion breakthrough seen as an important step toward a clean energy future

In a first, US scientists have created “net energy” through a nuclear fusion reaction, the Department of Energy announced on Tuesday.

The successful experiment, which took place Dec. 5 at Lawrence Livermore National Laboratory, is the most significant milestone ever in the decades-long quest to produce cheap, clean, carbon-free energy through fusion. nuclear.

“We have taken the first steps towards a clean energy source that could revolutionize the world,” said Jill Hruby, administrator of the National Nuclear Security Administration.

Energy Secretary Jennifer M. Granholm called the achievement “one of the most awe-inspiring feats of science of the 21st century,” adding that it “will go down in the history books.”

In a nuclear fusion reaction, two atoms collide and fuse into a larger atom of a heavier element, releasing their excess mass as energy.

Fusion is the process by which the sun produces energy. The Sun’s core is the ideal high-pressure, high-temperature environment for hydrogen atoms to fuse into helium; replicating these conditions on Earth has proven to be much more difficult.

Scientists at Lawrence Livermore in the San Francisco Bay Area achieved their breakthrough by training 192 lasers at a diamond-coated target about the size of a peppercorn, heating it to more than 3 million degrees Celsius (over 5.4 million degrees Fahrenheit) and – briefly – mimicking star conditions. The merger has started.

“All of this had happened before. A hundred times before,” said Marvin Adams, National Nuclear Security Administration deputy administrator for defense programs. “But last week, for the first time, they designed this experiment so that the fusion fuel would stay hot enough, dense enough, and round enough long enough to ignite and produce more energy than lasers can’t. had filed.”

This net energy gain was “about two megajoules indoors, about three megajoules outdoors,” Adams said.

A fusion reaction generates three to four times more energy than fission, which itself is about a million times more powerful than any other energy source on Earth.

Nuclear fission, or the splitting of atoms, also releases a massive amount of energy in a chain reaction. Fission reactions have been channeled productively into nuclear power plants and destructively into nuclear weapons.

Unlike fission, nuclear fusion does not release harmful radioactive byproducts that take thousands of years to decay. And since it doesn’t involve a chain reaction, it’s inherently less dangerous.

Additionally, merging has long been seen as essential to achieving the goal of net zero emissions. The production of electricity and heat currently accounts for 30% of global greenhouse gas emissions. Technology that successfully harnesses nuclear fusion could, in theory, create endlessly renewable amounts of clean, low-risk, carbon-free energy.

All of these factors have made controllable nuclear fusion one of the most sought after goals of science since the 1950s, attracting billions in government and private investment.

“We’ve taken a technology that was born for destruction, and now we’ve opened the door to using it for more than that,” said Lee Bernstein, a UC Berkeley nuclear engineering professor and former deputy group leader at the Livermore Laboratory’s National Ignition Facility, where the experiment took place.

While Tuesday’s announcement is a major step toward that ideal, there’s still a long way to go. Any practical application is probably “decades away,” said Livermore director Kim Budil.

“It’s one ignition capsule, one time only. To achieve commercial fusion energy, you have to do a lot of things. You need to be able to produce very many fusion ignition events per minute,” Budil said. “With concerted effort and investment, a few decades of research into the underlying technologies could put us in a position to build a powerhouse.”

Indeed, Livermore’s achievement is “much like the Wright brothers’ first flight,” said Caltech plasma physicist Paul Bellan.

With their self-designed airplane, Orville and Wilbur Wright proved in 1903 that “you could make a heavier-than-air craft that would take off and fly without falling,” Bellan said. “That didn’t mean you could fly from LA to London” right away. Nor did it mean that the Wrights’ plane was the only workable design for an airplane, he added. But it proved that a bold leap in physics was possible and inspired others to build on their success.

“It’s a defining moment, definitely,” Bellan said. “It shows that it’s worth working on, and eventually we’ll come up with something that will pay off.”

Although it takes decades for fusion to be commercial, nuclear fission technology has powered the United States for decades. Ninety-three nuclear reactors generated almost a fifth of the country’s electricity last year; among them is the Palo Verde plant just off Interstate 10 in Arizona, which powers Los Angeles and other cities and is the nation’s largest electricity generator. President Biden sees nuclear power as crucial to achieving his goal of 100% climate-friendly electricity by 2035.

Even before Tuesday’s historic announcement, a string of successes at the National Ignition Facility had inspired new generations of scientific talent. Since August 2021, when the team reached a key threshold in achieving a self-sustaining reaction, student interest in fusion has increased, said Siegfried Glenzer, professor of photon science at the University of Stanford and Division Director at SLAC National Accelerator Laboratory.

“It really is a big magnet now for young people who want to make a difference in the world. Many are driven by climate change and want to see a carbon-free source of energy produced,” Glenzer said. exciting time for researchers of all ages.

Times writer Sammy Roth contributed to this report.