This video is brought to you by Curiosity
Stream. Even though the cost of solar and wind is
dropping, renewables might not be sufficient to meet our clean energy demand in the future. However, nuclear power can play a key role
in the decarbonization of the energy sector. And I’m not talking about nuclear fission. Rather, quite the opposite. I'm talking about fusion, with it's perpetual,
30-years-away target. But before you blow your *fuse* and start
leaving your fusion jokes in the comments, there's been a major fusion development we
have to talk about and it's kind of a nuclear bombshell ... poor choice of words ... it's
big news ... I'm Matt Ferrell ... welcome to Undecided. I had a chance to speak to Dr. Martin Greenwald,
a Deputy Director and Senior Research Scientist at MIT, who's part of the team that achieved
a pretty big fusion milestone. Before *bursting out* with the recent breakthrough
on nuclear fusion though, it's a good idea to take a step back and have a quick
recap on nuclear power. Don’t worry, I’ll keep it high-level as
I don’t want burn out your brain ... or mine. You can get nuclear energy through two processes:
fission and fusion. Nuclear fission reactors are what we see used
around the world today. In a fission reactor, you blast a neutron
into an unstable Uranium-235 atom to split it into smaller fragments, including more
neutrons. These new particles will hit other Uranium-235
atoms, which generates a chain reaction effect. The breakdown of the Uranium isotope releases
energy in the form of heat, which is then used to vaporize water. The resulting steam can then be used to power
a turbine to generate electricity. As the name suggests, the fusion process is
basically the opposite of fission. Instead of splitting, we're putting things
together. A fusion reactor replicates what happens naturally
within the suns core, which sounds scary, but it's not. Now where hydrogen isotopes split and then merge into helium nuclei under
*astronomical* temperatures and pressures. In this case, the fusion reaction produces
4 times more energy than what's obtained through the fission process. Instead of using uranium or plutonium, which
both release long-lived radioactive particles, you feed hydrogen isotopes like Deuterium
and Tritium into a fusion reactor. Deuterium is a stable element and Tritium
radioactivity doesn’t last long. Besides being safer and more eco-friendly,
the fusion fuel sources are more abundant and cheaper than fission fuels. That’s because you can extract Deuterium
from seawater, while you can get Tritium during the fusion reaction itself when neutrons interact
with elements like lithium. Or as Dr. Greenwald put it: It's a potentially ideal source of energy. First of all, the fuel is essentially unlimited. And it's, it's extremely energy, energy density form of fuel. So a tenth of a gram of deuterium and three
tenths of a gram of lithium if fused in a power plant would make enough
electricity for an average American for a year, a full year. And, and those few tenths of a gram you wouldn't
need, if it was in your pocket, you wouldn't even notice it it's like lint or something
like that. Fusion's potential benefits over fission aren't
just about higher energy production and fuel energy density though. One of the biggest, is probably one you've
thought of. The by-products of fission are highly radioactive
and, if not appropriately controlled, can contaminate the planet for decades. On top of that, fission's chain reaction can
degenerate and can potentially get out of control causing a nuclear meltdown or explosion,
which is what happened in Fukushima in 2011 after the tsunami hit the power plant and
caused a series of failures. This type of incident wouldn't happen in a
tokamak, which is based on magnetic-confinement fusion (MCF). A tokamak is a doughnut-shaped chamber where
you heat hydrogen isotopes up to 150 million degrees. I don’t know about you, but this isn't the
type of reactor I want Homer Simpson in charge of. At such a high temperature, the atoms are
stripped of their electrons and turn into ions. You're then left with a superheated ionized
gas, which is plasma. Under these conditions the charged particles
collide and fuse together ... just like in the sun. Another safety net for fusion is that you
can stop the reaction just by cutting off the fuel supply. In nuclear fission, that's not the case. It can't melt down the way a fission
plant can. It doesn't have the same kind of waste materials. So, it has all these advantages. The other thing is it doesn't use a lot of
land, a lot of water. It's a very good compliment to renewables. ...it could be used for process heat for industry. It would be relatively straightforward in
certain industries like making cement. So based on all that, let’s go for fusion ... we've got our winner. That'd be great, but that's where the running
joke of fusion always being 30 years away comes in. Nobody has produced a fully functional fusion
power reactor yet. It takes an insane amount of energy
to produce the heated plasma so right now the power you put into a fusion reaction is
always higher than the thermal power that you get out of it. To assess how well a reactor performs is referred
to as the “fusion energy gain factor" or the symbol Q with a ratio. Basically, you want a Q value higher than 1, which is that thermal power breakeven point within the reactor. But we’re not even close to breakeven. The Joint European Torus (JET) held a record ratio at 0.67 but the National Ignition Facility (NIF) just recently broke that with a Q of 0.7. But it's really important to note that Q isn't
accounting for the full power and electricity required to run the facility and how much
electricity it can actually generate from the reaction. Q is just about the thermal power in versus
thermal power out. For the full picture, that accounts for all
of those additional energy costs and converting heat into electricity ... basically, producing
more electricity than it takes to run the facility ... we'd most likely be looking at
a Q somewhere between 10 and 25. There's a lot of moving pieces. We have to learn to walk before we can run
and hitting a Q of 1 or higher is us learning to walk. That's why at this phase of fusion research,
everyone focuses on the Q ratio just for the plasma reaction itself. Once we hit that, the focus will shift towards
overall power gain. In 2025, the massive international fusion
project known as ITER is supposed to start producing superhot plasma with a Q greater
than 10 in France. Even though the project was born in the 1980s,
construction of the tokamak only started in 2007. Once it's complete, ITER will be the world’s
largest fusion rig, which isn't necessarily a good thing. Due to its size and scope it’s taking a
long time and tens of billions of dollars to build. Plus, it’s designed to be a testing facility
and not a working reactor ... and won't reach full operation until 2035. So even if it's 100% successful, we still
need to go through the process of then building out the final working reactor design. Now, I know that sounds a lot like we’re
still 30 years away from having a fully operational fusion reactor. But there has been some *electrifying* breakthroughs
recently from smaller and more nimble approaches, like what Dr. Greenwald has been working on. One of the biggest challenges with MCF fusion
reactors is the incredible magnetic field they have to generate to contain the plasma. Massive magnets ringing the rig, or the doughnut,
create an intense magnetic field. This invisible bubble traps the blisteringly
hot and electrically charged slurry in midair near center of the reactor. Being kept away from the rig walls, the plasma
won’t melt them. And just this September we found out that
2021 is going out with a nuclear fusion bang. But before getting to this big piece of fusion
news, I'd like to thank today's sponsor, CuriosityStream. If you'd like to watch more videos on topics
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to CuriosityStream, and to all of you, for supporting the channel. So back to 2021 going out with a nuclear fusion
bang. The Massachusetts Institute of Technology
(MIT) along with the Commonwealth Fusion Systems start-up (CFS) , designed one of the most powerful magnets ever created on Earth. This joint experiment hit on something extremely important. Managing to generate an incredible magnetic field with far less power. To achieve this milestone they used something called a high temperature superconductor (HTS). The major innovation is actually not that
new. Back in 2015, MIT proposed using this superconducting tape in their device design. And I mean a lot of it. The test magnet used 267 km (166 miles) of tape. This material retains superconductivity at
high temperatures, which generates a more intense magnetic field. Martin gave me some really nice insights about
this tape. The new material, the high temperature
superconductor, which is really a ceramic like compound of rare earths and barium copper
oxide, it's a fairly fragile material, but people learned how to put it down as a thin
film on a strong sub-structure. And it turns out there was a breakthrough in technology that we could take advantage of That we weren't responsible for. It was an invention discovery really by some
IBM scientists working at a lab in Zurich in the '80s and that was high temperature
superconductors. It didn't really look like an engineering material, and a lot of people thought, well,
this is really interesting scientifically but this will never be practical. You'd never be able to build a magnet or a
wire out of this. But it had a lot of promise and we followed
this very closely because we thought, well, this material could allow us to make a superconducting
magnet that ran at high enough fields. This is something I find fascinating about
fusion development, and why it's been taking so long It's taken decades to learn about new materials
and techniques that can be applied to successfully control a fusion reaction at scale. Martin brought up a point that I hadn’t
considered. The advantage of using this material wasn’t
just making the magnet more powerful but also more energy efficient. You can make great experiments and we're
able to get very high fields with copper magnets. But they consume an enormous amount of electricity ... enormous amount of power. So, that turned out to be a good deal as a
stronger magnetic force translates into a 10 times greater power generated by the reactor. As a result, the MIT design is meant to achieve
net energy gain in a much smaller unit. If you were able to go to higher fields,
you can make the linear dimension smaller. You can shrink the size. When you compare it to the ITER system, which
uses low-temperature superconductors, the SPARC reactor MIT and CFS are designing is
only 2% of its size. And that’s a significant reduction in construction
cost and time. But does it work? The big milestone that MIT and CFS just achieved
in their recent test was putting together one full-sized magnet and running it through
tests as if the full tokamak was built out. That test went extremely well ... just how
well? It reached a magnetic field of 20 tesla. That's the unit we use. It's not the highest field ever produced,
or the highest field with HTS ever; those were produced in small magnets. But it's the combination of the size and the
field that really puts it in a class by itself. The bottom line is that this test proved out
the math and theory of Commonwealth Fusion Systems' SPARC reactor design. This test was the final proof of concept they
needed before moving on to the full build out. It worked very successfully and it really
unlocked. It was the last piece of the puzzle to allow
us to proceed. We've done work on the physics basis for this
new experiment, and we published that about a year ago. I don’t know about you, but I was...supercharged...when
I heard all of this. And that’s not just from my conversation with Martin. After 3 years of research, scientists nearly
doubled the intensity of the field which led to a tenfold increase in the power generation. That’s why the project leaders
now herald this to be a key milestone for building a low-carbon energy-positive fusion
reactor. MIT and CFS are now...aiming for the stars... In 2025 they will demonstrate SPARC, the world’s
first demonstration fusion device that creates net energy output. Now we've just got to finalize the design
and build the machine. And we hope that it'll be operating by 2025,
and producing fusion power shortly thereafter. So, how much power are we talking about? What we use for our estimates of how
it will perform is the same set of physics rules that are used for the ITER experiment. Remember that ITER is predicted to have a
Q greater than 10 and so does SPARC. To develop this...stellar...prototype, CFS
has raised over $250 million. You may see why this may...spark...a revolution
in nuclear fusion that could drastically shrink the infamous 30-year window. This sounds amazing. But is there anything...bursting...the magnetic
fusion bubble? Because of the compact SPARC design, you'll
have a greater power density, which means a higher heat load generated in the reactor
core during the fusion process. That higher heat load makes managing the high
temperatures a challenge. The structure surrounding the magnet needs
to be kept cold enough to absorb the thermal stresses. But we won't have to wait long to find out
how well it handles that because in 4 years the SPARC test plant may be able to verify
these technical features. In the meantime, the project leaders are planning
a lot of work behind the scenes. Milestones now, they're maybe less flashy...
the completion of the first building the completion of the test cell, arrivals of some
major components. So they're not going to be big flashy things,
but very important for the project. And there's one thing I have to address. If you've been following fusion research,
you'll know that all of these fusion reactor tests are typical running for a few seconds
at a time. That's not necessarily an issue with fusion
reactors in general, but it's how these test devices are built to save on cost while they
prove out key concepts. Those experiments often have very, very short pulse lengths. Due to the physics of the experiment. I mean, the machines are not designed to be long-pulsed. They would have to be considerably more expensive. There would be much more costs up front. I can hear you already. Is fusion going to happen in our lifetime? If we produce net power in a device which
can demonstrably scale up, that will attract funding. It'll basically change the narrative from
fusion in 30 years always to, okay, this is real, and it would attract the kind of investment
to start building out as an industry. So, that's our hypothesis. We're testing it. We have fairly audacious goals, but you kind
of have to have audacious goals if you want to play in this particular arena I don’t know if we’re still going to be
30 years away from fusion in 4 years. Jokes aside, I believe a cheaper and safer
nuclear power will be essential for the future of green energy. While there are still plenty of hurdles to
overcome, this recent breakthrough proves that getting unlimited power from fusion may
be a realistic and achievable goal sooner than you think. So what do you think of fusion? Do you think this recent milestone is a game
changer? Jump into the comments and let me know. And thanks as always to my patrons and welcome
to new Supporter+ members David Whitehouse and Robert Clark. Your direct support really helps with producing
these videos. Speaking of which, if you liked this video
be sure to check out one of the ones I have linked to right here. And subscribe and hit the notification bell
if you think I’ve earned it. Thanks so much for watching and I’ll see
you in the next one.
Thank you for posting this! I've been super excited about SPARC since I learned of the project last year. As a layman, SPARC seems like the most realistic near-term commercial use fusion technology. But ITER is getting all the attention and well-warranted caution about "20 years from now".
SPARC army, assemble!
I recently sat through a talk by a plasma physicist. He was really excited about this project.
The SPARC team apparently has solved the material requirements of making a superconductor that can handle the amount of current (without overheating) needed to sustain a magnetic field sufficient for fusion. The team is very confident about having a test ready in 2025 (though realistically probably 2025) which will have a Q of 4 or 5. Granted, Q only tracks energy going into and out of the fusion reaction, the inefficiencies of electricity in and electricity out means it still would not produce useful power.
After SPARC they plan to finish their next reactor ARC in ~2030 which will have a Q much higher and will actually produce useful energy.
The team is confident that they have solved all the major hurdles to make this happen. The professor who gave the talk said that this was the first time that he actually thinks there's a good chance of seeing useful fusion in his lifetime.
Just watching this now and the the first half video heavily borrows clips from the SFIA one.
Great vid, though. I truly believe we'll have the first commercial fusion power plants online before 2040. And they won't need to be giant ones like ITER, they will be comparable to the size of a coal firing plant today.
Then we can finally get over the "global warming" problem -- which is a problem -- but IMO is nowhere near as serious and pressing a problem as habitat destruction, which we need to start reversing. Like now!