Nuclear physicists from the Bay Area will be center stage Tuesday at a Department of Energy announcement about a breakthrough in fusion technology that could ultimately lead to clean energy plants without hazardous nuclear waste.

A big advance in nuclear fusion — maybe the first in two generations? — is coming out of the Lawrence Livermore National Laboratory on Tuesday, and it's one that physicists have been waiting on for a long time. Reportedly, an experiment at the lab involving its National Ignition Facility (NIF) succeeded in generating more power than it required to produce the reaction — which Gizmodo refers to as the "holy grail" of fusion research.

The Financial Times broke the story about the experiment's success, and the New York Times separately confirmed the story through retired plasma physicist Stephen Bodner. U.S. Energy Secretary Jennifer Granholm will be helping make the announcement Tuesday, which is said to be about a "major scientific breakthrough."

If you want to delve into the details, the NYT's Kenneth Change explains it thusly:

Fusion is the thermonuclear reaction that powers the sun and other stars — the fusing of hydrogen atoms into helium... NIF consists of 192 gigantic lasers, which fire simultaneously at a metal cylinder about the size of a pencil eraser. The cylinder, heated to some 5.4 million degrees Fahrenheit, vaporizes, generating an implosion of X-rays, which in turn heats and compresses a BB-size pellet of frozen deuterium and tritium, two heavier forms of hydrogen. The implosion fuses the hydrogen into helium, creating fusion.

Up until now, fusion reactions have been synthesized in doughnut-shaped reactors called tokomaks — a technology that dates back to the late 1950s in Russia. The giant laser array at NIF, which the Times notes is very expensive to operate, takes a different method known as "thermonuclear inertial fusion." And the breakthrough experiment was reportedly able to generate a reaction in which "the fusion energy produced exceeded the amount of laser energy hitting the hydrogen target."

"For that to occur," the Times explains, "the fusion reaction had to be self-sustaining, meaning the torrent of particles flowing outward from the hot spot at the center of the pellet heated surrounding hydrogen atoms and caused them to fuse as well."

While significant in terms of the science, multiple sources caution that we are likely many years away from building facilities at scale that can efficiently and effectively replicate this process.

"It’s about what it takes to boil 10 kettles of water,” says Jeremy Chittenden, co-director of the Centre for Inertial Fusion Studies at Imperial College in London, speaking to CNN about the amount of energy that was produced in this experiment. "In order to turn that into a power station, we need to make a larger gain in energy – we need it to be substantially more."

And as the Times explains, "The [NIF] laser complex fills a building with a footprint equal to three football fields — too big, too expensive, too inefficient for a commercial power plant... [And] a manufacturing process to mass-produce the precise hydrogen targets would have to be developed."

Photo of Lawence Livermore Lab via Wikimedia