“From my perspective, this is the proof that the physics work for net gain,” said Andrew Holland, CEO of the Fusion Industry Association, an industry advocacy group.
Here are several important things to know about the milestone’s significance and next steps:
Why is this so important?
In theory, nuclear fusion could produce massive amounts of energy without producing long-lasting radioactive waste, or posing the risk of meltdowns. That’s unlike nuclear fission, which powers today’s reactors.
Fission results when radioactive atoms — most commonly uranium — are split by neutrons in controlled chain reactions, creating lighter atoms and large amounts of radiation and energy to produce electric power.
Fusion is the opposite process. In the most common approach, swirling hydrogen isotopes are forced together under tremendous heat to create helium and energy for power generation. This is the same process that powers the sun and other stars. But scientists have been trying since the mid-20th century to find a way to use it to generate power on Earth.
So what did the DOE scientists do?
Researchers at a weapons lab at the department’s Lawrence Livermore National Laboratory in California used the world’s most powerful lasers to fuse hydrogen atoms. In the process, they generated more energy than the lasers delivered, industry officials familiar with the experiments said ahead of Tuesday’s announcement.
DOE would not comment on accounts of the laboratory’s fusion success, which the Financial Times first reported Sunday. But the department said in a news release that it would announce a “major scientific breakthrough” on Tuesday.
In their experiments, scientists at Lawrence Livermore’s National Ignition Facility fire a “shot” from a cluster of lasers at a container enclosing a small capsule holding hydrogen isotope fuels. The laser beams hitting the container generate X-rays that bombard the fuel, triggering an inward-directed explosion that melds the hydrogen atoms together.
Scientists outside DOE believed the lab was able to increase the power of the laser shot, creating a fusion reaction that yielded more energy than the lasers produced, according to Stephen Dean, president of Fusion Power Associates, a nonprofit organization that advocates for fusion power.
The ignition laboratory’s implosions are over in billionths of a second. That’s long enough, however, to provide important data to the facility’s scientists researching nuclear weapons, Dean said.
Tuesday’s announcement has been at least a decade in the making, and hit a new milestone a little more than a year ago.
In an August 2021 test, Lawrence Livermore scientists reported hitting a record new output from its cluster of lasers, hitting a target the size of a BB to generate 10 quadrillion watts of fusion power for 100 trillionths of a second. The fusion reaction produced 70 percent of the energy that had gone into the laser shot, the journal Nature reported at the time — approaching, but not yet reaching, the achievement being announced Tuesday.
Would future commercial fusion reactors use DOE’s process?
Private fusion companies have raised nearly $5 billion from wealthy investors and corporations hoping to get in on the ground floor of a possible mega-industry of the future. And they have pursued various means of achieving that goal.
The biggest investments have gone to companies developing doughnut-shaped reactor designs called by a Russian name — tokamak. This approach to fusion power competes with Lawrence Livermore’s fusion ignition process.
A tokamak works by heating to over 100 million degrees Celsius, creating a swirling plasma of hydrogen isotopes that — if all works as planned — would collide to create the fusion reaction. Magnetic fields generated by super-magnets would then contain the plasma to keep it from destroying the reactor.
A massive international project under construction in France that the United States is a part of — the International Thermonuclear Experimental Reactor — envisions a tokamak reaction. That project has made steady progress, but has also faced cost overruns and delays. In November, the organization reported challenges with first-of-a-kind components that needed “extensive repairs.”
What is the next step in fusion development?
Fearful that China might wind up dominating fusion energy in the second half of this century, Congress in 2020 told DOE to begin funding development of a utility-scale fusion pilot plant that could deliver at least 50 megawatts of power to the US grid.
The pilot plant is to be a key test of whether fusion reactors can be workable and affordable as the nation’s everyday main source of electricity, observers say. DOE hopes that private companies will form teams of experts from national laboratories and universities to speed up their research.
In September, DOE invited private companies to apply for an initial $50 million in research grants to help fund development of detailed pilot plant plans.
“We’re seeking strong partnerships between DOE and the private sector,” a senior DOE official told POLITICO’s E&E News recently. The official was not willing to speak on the record, saying the grant process is ongoing and confidential.
As the competition proceeds, DOE will set technical milestones or requirements, challenging the teams to show how critical engineering challenges will be overcome. DOE’s goal is “hopefully to enable a fusion pilot to operate in the early 2030s,” the official added.
At least 15 US and foreign fusion companies have submitted requests for an initial total of $50 million in pilot plant grants, and some of them are pursuing the laser-ignition fusion process that Lawrence Livermore has pioneered, said Holland. He did not name the companies because the competition is confidential.
What are the key hurdles?
The ignition process that Lawrence Livemore scientists pioneered requires exacting maintenance of the laser cluster in between shots. A typical target costs $100,000 or more and requires hundreds of hours to construct, said British mathematician and author Arthur Turrell, who was present for one Lawrence Livermore shot.
Making this technology work on a commercial scale would escalate those requirements.
“Once you get a single shot working well, you have to repeat it, 10 times a second” to have a sustained commercial reaction, a senior DOE official said recently, speaking on condition of anonymity because DOE’s pilot plant program is in the confidential application stage. “That requires a laser that can fire 10 times a second. It is not fundamentally impossible, but it is very difficult from an engineering perspective.”
With tokamaks, reactors face the challenge of having to make their own fuel, breeding one of the hydrogen isotope fuels — tritium — inside the reactors. There is also a need to improve the protection of the reactor from intense heat and neutron bombardment.
“It’s not straightforward once you’ve made fusion happen as we have, to go to commercial fusion,” said Steven Cowley, director of DOE’s Princeton Plasma Physics Laboratory, at a White House conference on fusion in April. “But we have the tools to do it.”
The steepest hurdle may be money. Companies have to prove there is a path to a cost for fusion that could be competitive, said Geoff Olynyk, a senior expert in sustainability at McKinsey & Co., in an interview.
“All of the fusion companies are targeting that, but there’s no proof that any of them can do it. The first demonstrations will be extremely expensive,” he said. “It’s a race right now to get some of these pilot plants online.”