The Department of Energy announced Tuesday that its scientists have produced the first ever fusion reaction that yielded more energy than the reaction required, an essential step in the long path toward commercial fusion power, officials said.
The experiment Dec. 5, at the Lawrence Livermore National Laboratory in California, took a few billionths of second. But laboratory leaders said today that it
demonstrated for the first time that sustained fusion power is possible.
What comes next is even harder: Proving that the technology can work not only in highly structured laboratory experiments but eventually in commercial reactors. That may take decades. But DOE’s achievement of a “net gain” of energy in the lab gives another boost of confidence to a growing corps of fusion entrepreneurs and researchers.
“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, in an
interview before the announcement.
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 lost-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?
Firing an energy “shot” from world’s largest cluster of lasers, scientists at Lawrence Livermore’s National Ignition Facility ignited a BB-sized fuel pellet, achieving 100 million degrees Celsius — 10 times hotter than the temperature at the center of the sun.
The ignition required a little over two units of laser energy and produced 3.15 units of heat energy in the instantaneous reaction, the
production of “net energy” that scientists at the lab have pursued for more than 60 years.
Tammy Ma, a plasma scientist at the facility, said she got the news of the results while waiting for a flight. “I burst into tears” and began jumping up and down in joy, she said Tuesday.
Last week’s breakthrough followed on the heels of an August 2021 test, in which Lawrence Livermore scientists reported hitting a record new output from its cluster of lasers. That reaction produced 70 percent of the energy that the laser shot delivered, the journal Nature reported at the time — approaching, but not yet reaching, the achievement announced Tuesday.
One critical caveat: Firing the lasers, which fill a facility the size of three football fields, required about 300 units of electric power for last week’s experiment. That shows that the reaction itself was not a foundation for a sustainable, affordable fusion plant, officials said Tuesday.
Still, Ma noted that the experiment’s lasers are based on
engineering from the 1980s and 1990s, dating from the facility’s longstanding work on nuclear weapons. Modern lasers are much more efficient, she said.
Would future commercial fusion reactors use DOE’s process?
Not necessarily.
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.
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