US Lab Makes Fusion Energy Breakthrough

U.S. scientists say they have made a historic scientific breakthrough in fusion energy that could pave a path toward advanced clean power and national defense.

A team of scientists at the Lawrence Livermore National Lab’s National Ignition Facility in California conducted a controlled fusion experiment Dec. 5 that successfully resulted in more energy produced than the laser energy used to power the experiment.

“The fusion fuel stayed hot enough, intense enough and around enough for long enough that it ignited, and it produced more energy than the lasers had deposited: about 2 megajoules in, about 3 megajoules out,” Dr. Marvin “Marv” Adams, deputy administrator for defense programs for the National Nuclear Security Administration (NNSA), explained during an Energy Department event Dec. 13. “The energy production took less time than it takes light to travel one inch. Kind of fast. So, this is pretty cool.”

Fusion occurs when two light nuclei are heated to extreme temperatures. The heat causes the nuclei to fuse together to form one heavier nucleus, releasing large amounts of energy. Neither greenhouse gases nor radioactive byproducts are released.

Making a breakthrough

As part of the experiment, the scientists fired 192 laser beams into a capsule to hit a target about the size of a peppercorn, heating the inner wall of its capsule to more than 3 million C and depositing energy. Conditions of a star were briefly simulated, said NNSA Administrator Jill Hruby.

X-rays from the walls impinged on the capsule, squeezing the fusion fuel— comprised of hydrogen isotopes called deuterium and tritium—and depositing energy. All of this has happened in previous experiments, according to Adams.

But, last week, the experiment resulted in a net energy gain for the first time.

The science behind the discovery is the same that enables the sun and other stars to produce energy. The fusion ignition achievement will allow scientists to probe conditions at the center of nuclear explosions and to take steps to a clean energy source, according to Hruby.

“Going forward, we know we will make further breakthroughs; we will have further setbacks. But all of this is in the interest of promoting national security, pushing towards a clean energy future and redefining the boundaries of what’s possible,” she said.

Kimberly Budil, director of Lawrence Livermore, said the lab’s pursuit of fusion ignition over the past decade has been an ambitious technical goal.

“Many said it was not possible. The laser wasn’t energetic enough, the targets would never be precise enough. Our modeling and simulation tools were just not up to the task,” she said. “Progress has taken time.”

Work in fusion energy, Budil added, is what national labs are made for: “tackling the most difficult scientific challenges head on, learning from the inevitable setbacks and building toward the next idea.”

Science and technology hurdles mean commercialization is probably not five or six decades away, but sooner, according to Budil.

“To realize commercial fusion energy, you have to do many things. You have to be able to produce many, many fusion ignition events per minute, and you have to have a robust system of drivers to enable that,” she said. “With concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant.”

Industry reacts

Nuclear scientists outside the lab said the achievement will be a major stepping stone, but much more science remains to be done before fusion becomes commercially viable.

Tony Roulstone, a nuclear energy expert at the University of Cambridge, estimated that the energy output of the experiment was only 0.5% of the energy that was needed to fire the lasers in the first place.

“Therefore, we can say that this result ... is a success of the science but still a long way from providing useful, abundant, clean energy,” Roulstone said. In order to become commercial, a power plant would have to produce enough energy to power the lasers and to achieve ignition continuously.

The electricity industry cautiously welcomed the step, though it emphasized that in order to carry out the energy transition, fusion should not slow down efforts on building out other alternatives like solar and wind power, battery storage and nuclear fission.

“It’s the first step that says ‘Yes, this is not just fantasy, this can be done, in theory,’” said Andrew Sowder, a senior technology executive at EPRI, a nonprofit energy research and development group.

Debra Callahan, who worked at Lawrence Livermore until late this year and is now a senior scientist at Focused Energy, said the lab’s results will help companies figure out how to make lasers more efficient. “Everyone is excited about what's been achieved and what's in the future.”

Focused Energy is one of dozens of companies working to commercialize fusion energy, and it has raised about $5 billion in private and government funding in recent years.

Reuters contributed to this article.