ILMA Compoundings - June 2020 - 12

INDUSTRY RUNDOWN

How Close Are Scientists
to Viable Nuclear Fusion
Power?
In the middle of the 20th century, when scientists began
working on nuclear fusion, the first nuclear fission
plants were going online. Nuclear "fission" operates
by splitting atoms, whereas "fusion" combines atoms.
Fusion is what powers our sun. Fission is what powers
our nuclear plants today.
The running joke among scientists is that we are just 50
years away from fusion being a viable energy source. So,
while we have learned how to create fission energy, we're still
chasing the elusive fusion. Why bother?
Leigh Winfrey, Ph.D, associate professor of nuclear
engineering at Penn State University, said, "The benefits of
nuclear fusion are significant."
While fission reactors must be located next to large bodies
of water and designed for each location to accommodate
variable safety conditions, fusion reactors can be built
virtually anywhere.
"Once you figured out how to make one, you can make
as many as you like, and you can put them wherever you'd
like," said Winfrey. "You can put it in a desert, you can put
it on a spaceship, you could put it on the moon, and you
could put it in the middle of the city."
With fission, the most significant safety challenge is
stopping the reaction. With fusion, the second you get the
balance wrong, it just turns itself off. Fusion byproducts,
primarily helium, are not radioactive like those of fission,
and fusion produces energy 4 million times that of fossil
fuels - and four times as much as fission.
Lately, fusion has been making headlines as companies
banking on this energy source predict they will have a viable
reactor in 15, 10 or even just five years. How is that possible?
Winfrey speculates that modern computing has something to do with it. She said that scientists and engineers
have always known what was needed to make fusion
happen, but it wasn't scalable. They needed to build massive

JUNE 2020

| COMPOUNDINGS | ILMA.ORG

magnets, much larger than those they built before. Thanks
to high-temperature semiconductors with higher magnetic
field densities, they can scale the power needed to put
magnetic fields in a smaller space.
Today's supercomputers allow scientists to model and
understand the physics far better. They can use that computing power to predict how to make fusion work properly and
operate safely.
Because of this improved understanding, Winfrey said
that more fusion startups with private investments are getting involved. About 15-20 companies globally are working
on fusion reactors, and Winfrey feels that half of them are
close to firing one up, or at least have a credible idea.
That private financing has spurred government investment, and now researchers such as Winfrey are getting
access to more funding, which allows more people to focus
on all the pieces to the puzzle. Winfrey said that out of
25-30 Ph.D. candidates her adviser graduated during his
tenure, she is the only one working in fusion. By comparison, Winfrey has graduated five students, and all but one are
working in fusion.
But successfully starting a fusion reactor is only the first
step. It has to be kept running to generate power. The pieces
of the puzzle that Winfrey and her team are working on
are plasma material interactions. They are trying to find
a material that won't be damaged immediately by what is
essentially a solar flare.
"There's a lot involved, and that mechanism is not well
understood because we had no reason previously to understand it," explained Winfrey. "We have to first ask, 'How do
we understand it?' and then, 'How do we go about engineering solutions that will last more than one event?'"
When does Winfrey think we will have fusion power? "I will
definitely say I think I will see a demonstration power plant in
my lifetime. I'm 37, so let's say 50 years, give or take."

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ILMA Compoundings - June 2020

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