Kind: captions
Language: en
The following is a conversation with
David Curtley, a nuclear engineer,
expert on nuclear fusion, and the CEO of
Helium Energy, a company working on
building nuclear fusion reactors and
have made incredible progress in a short
period of time that make uh it seem
possible like we could actually get
there as a civilization. This is
exciting because nuclear fusion, if
achieved commercially, would solve most
of our energy needs in a clean, safe
way, providing virtually unlimited clean
electricity. The problem is that fusion
is incredibly difficult to achieve. You
need to heat hydrogen to over 100
million° C and contain it long enough
for atoms to fuse. That's why the joke
in the past has been that fusion is 30
years away and always will be.
Just in case you're not familiar, let me
clarify the difference between nuclear
fusion and nuclear fision. By the way, I
believe according to the excellent
sample size subreddit post by PM
Goodbeear on this, the preferred
pronunciation of the latter in US is
nuclear vision like vision and in the UK
and other countries is nuclear fishision
like mission. I prefer the nuclear
fision pronunciation because America.
So uh today's nuclear power plants use
nuclear fision. They uh split apart
heavy uranium atoms to release energy.
Fusion does the opposite. It combines
light hydrogen atoms together. The same
reaction that powers the sun and the
stars. The result is that it's clean
fuel from water. No longived radioactive
waste. inherently safe because a fusion
reactor can't melt down. If uh something
goes wrong, the reactor simply stops and
there's uh no carbon emissions. On a
more technical side, Helium uses a
different approach to fusion than has
traditionally been done. Most fusion
efforts have used Takamax, which are
these giant donut-shaped magnetic
containment chambers. Helium uses pulse
magneto inertial fusion. David gets into
the super technical physics and
engineering details in this episode
which was fun and fascinating.
I think it's important to remember that
for all of human history we've been
limited by energy scarcity and every
major leap in civilization, agriculture,
industrialization, the information age
came in part from unlocking new energy
sources. If someone is able to solve
commercial fusion, we would enter a new
era of energy abundance that
fundamentally changes what's possible
for us humans.
I'm excited for the future and I'm
excited for Super Technical Physics uh
podcast episodes. This is the Lex
Freeman podcast. to support it. Please
check out our sponsors in the
description where you can also find
links to contact me, ask questions, give
feedback, and so on. And now, dear
friends, here's David Curtley.
Let's start with the big picture. What
is nuclear fusion? And maybe what is
nuclear fusion? Uh let's lay out the
basics. So fusion is what powers the
universe. Fusion is what happens in
stars and it's where the vast amount of
energy that even that we use today here
on earth comes from the process of
fusion. It also is what powers plants
and those plants become oil and those
become fossil fuels that then powers the
rest of human civilization for the last
hundred years. And so fusion really
underpins a lot of what has enabled us
as humans to go forward. However,
ironically, we don't do it actively here
on Earth to make electricity yet. And
so, fundamentally, what fusion is is
taking the most common elements in the
universe, hydrogen, and lightweight
isotopes of hydrogen and helium, and
fusing those together to make heavier
elements. In that process, as you
combine atomic nuclei and form heavier
nuclei, those nuclei are slightly
lighter than the sum of the parts. And
that comes from a lot of the details of
quantum mechanics and how those
fundamental particles combine and
interact. Um, we also talk about the
strong nuclear force that holds the
atomic nucleuses together as one of the
fundamental forces involved in fusion.
But that mass defect E= MC² we know from
Einstein is also energy and so in that
process a tremendous amount of energy is
released and the actual reactions I
think is a lot more interesting than
simply it's a little bit lighter and
therefore energy is released but that's
the fundamental process in fusion is
you're bringing those those lightweight
atomic nuclei those isotopes together.
Fision is the exact opposite where
you're taking the heaviest elements in
the universe, uranium, plutonium, things
that are so heavy and have so many
internal protons and neutrons and
electrons that they're barely held
together at all. They're fundamentally
unstable or radioactive. And those
elements are very close to falling
apart. And as they do that, if you take
a uranium 235 or a plutonium 239 nucleus
and you add something new, usually it's
a neutron, a subatomic particle that's
uncharged, that unstable, that very
large nuclei will then break into
pieces, many pieces, a whole spectrum of
pieces. But if you add up all of those
pieces, they also have slightly less
mass than the initial one did. The
initial uranium or plutonium. And in
that process again E= MC² a tremendous
amount of energy is released. There's a
very famous curve in atomic physics
fusion or fision looking at the periodic
table going from the lightest elements
hydrogen to the heaviest elements those
uranium plutonium and others. And fusion
happens up to iron. Iron is the magical
point in between where lighter elements
than iron fuse together and heavier
elements fizz or uh are fizzile and
break apart and release energy.
I think about and I look at that process
uh in stars and that our star is
fundamentally an early stage star that's
burning just hydrogens. But when it
burns and does fusion, those hydrogens's
combine into heliums and later stage
stars can then burn those heliums and
they can fuse those together to form
even heavier elements and carbons and
those carbons can fuse together and form
heavier elements. And um that whole
stellar process is something that
inspires us at helon to think about what
are fusion fuels not just the simplest
ones but more advanced fusion fuels that
we see in stars throughout the universe.
Okay. So there's a million things I want
to say. So first maybe zooming out to
the biggest possible picture. If we look
across hundreds of millions billions of
years and all the my opinion alien
civilizations that are out there they're
going to be powered likely by fusion. So
our advanced intelligent civilization is
powered by fusion in that the sun is our
power plant.
>> Uh then the other thing is the physics
again very basic but you said E= MC² a
couple times.
>> Can you explain this equation? Equals
mc^ squ is a fundamental relationship
that a patent clerk Einstein discovered
and unlocked an entire new realm of
physics and engineering and has shown us
atomic physics. What happens inside the
nucleus and unlocked our understanding
of the universe and paved the way for
many of the physics advancements that
came after that. We think about mass as
these particles but in reality also at
the same time they're energy and there's
a direct quantitative relationship
between how much energy is in all of
that mass and in fact all of the energy
that is released even by by atomic
physics sure certainly in atomic
reactions is equals mc^2 and that that I
think most people have heard of and are
used used to but also in chemistry and
in chemical bonds that in those chemical
bonds there is a change in mass. When
you take a hydrogen and an oxygen and
you burn them and you combine them into
water, there's a change in mass. Now,
that change per atom and per molecule is
actually so small that it's extremely
hard to measure, but but it's still
there and that's the energy that is
released and you can quantify that. We
use uh units of electron volts um as a
unit of what is the energy in atomic
processes or chemical processes. Can you
also just speak to the the different
fuels that you mentioned both on the
fusion and the fision side? So uranium
plutonium for the fision and then
hydrogen isotopes for the fusion. So for
fision, uranium and plutonium, we don't
make those nuclei. Those right now for
humanity, those have been made in the
primordial universe through super
supernova and big bang um and the
initial formation of the universe where
matter was created. And so we dig those
up. We dig up uranium, plutonium out of
the ground. Um and in fact, most
plutonium we make from uranium. And we
can talk about how to enrich uh uranium
if if we want to go down that road. But
that's how we get those molecules and
nuclei. For fusion materials,
hydrogenetic species or hydrogens um are
primordial in the universe. Also only
the most common things that are in the
universe. The sun suns and stars are
made up of hydrogens and heliums. Um and
so the vast majority of atoms in the
universe still are hydrogen. So the
basic fuel for vision is already in the
ground and then the basic fuel for
fusion is everywhere is everywhere and
we particularly use a type of hydrogen
called dutyium which is a heavier
isotope of hydrogen. Hydrogen is
typically one proton and one electron
atomic mass of one. Dutyium is an atomic
mass of two which is a proton which is
charged particle and it has a neutron in
its nucleus which is an uncharged
particle. And so that's dutyium as the
fuel. Now, dutarium is also found in all
water on Earth. In the water I'm
drinking right now. It's in my body.
It's in Coca-Cola. Um, it's it's it's
everywhere.
>> Um, and and safe and clean and and one
of those fundamental particles that was
born in the cosmos. And we estimate that
in seawater here on earth we have if we
powered at our current use of
electricity
all of humanity on fusion somewhere
between 100 million years and a billion
years of fuel in hydrogen and dutarium
here on earth
>> and how is that stored mostly
>> and mostly that's just in water mostly
that it's a mix of we we call this
actually heavy water where you have
normal water that you're used to we talk
about and you learn in pool is H2O where
there's two hydrogens's and oxygen in a
nucleus in the molecule and dutarium or
heavy water is D2O two dutariums and an
oxygen um in reality it's actually an
interesting mix where you have some HDO
so a mix of hydrogen and dutarium you
also have other hydrogenic species
tridium is another one where you add a
second neutron to that hydrogen and then
you can have T2O tridiated water um and
that's something that that comes up and
and and we need to talk about at some
point. Um and there's other as you go up
the periodic table, you get add two
protons and you get helium. And so
helium, the most common helium is is
helium 4, which is two protons and two
neutrons. And then we use an isotope of
helium. The nucleus is called helion,
which is what we base the company after,
which is two protons and one neutron.
It's a light helium molecule. So the
number you mentioned in terms of uh how
much fuel is available basically the the
takeaway there is it's a nearly endless
resource in terms of fuel. Is that
correct to say? That's correct to say at
today's power level. I think what's
interesting is the idea that as we
deploy the same power source that powers
the universe here on Earth as humans,
can we do more? Can we have access to
much more electricity and much more
energy and do really interesting things
with that? And still there's large
amounts, millions and millions of years
of power um even at much higher output
power levels for humanity. Yes. So the
moment we start running out of uh
hydrogen and helium, we're that means
we're doing some pretty incredible
things with with with our technology.
And then that technology is probably
going to allow us to propagate out into
the universe and then discover other
sources cuz you can also get it on other
planets, whatever planets have water,
and it looks more and more likely like a
lot of them do. What a incredible future
just out into the cosmos. Nuclear power
plants everywhere. Yeah. Okay. So, uh to
linger on the some of the technical
stuff, you said uh strong nuclear force.
So, how exactly is the energy created?
So, how does the E= MC² the the M go to
the E uh in fusion? So in fusion you
take these lightweight isotopes like
hydrogen and dutyium and as you combine
them and get and take these molecules
and get them closer and closer together
some really interesting fundamental
physics happens. So first um these
atomic nuclei are charged. They have an
electric charge and they like charges
repel and I think everybody is familiar
with that where you take two positive
charges and you try to push them
together and the electromagnetic force
between them repels them. So you have a
force that's actually pushing against
them. So in fusion you work to get your
fuel very hot very very high
temperatures 100 million degree
temperatures. And temperature really is
kinetic energy. It's motion. It's
velocity. So that these particles are
moving so fast that even though they're
coming together and there's this
repulsive electromagnetic force, they
can still come close enough that another
force comes into play which is the
strong force. Um and then once you get
within a very close distance on the
order of the scale of those nuclei
themselves of those atomic nuclei, so
the tiniest thing you could imagine and
probably way smaller than that, these
particles then are attracted to each
other and they combine and they fuse
together. At that point you create
heavier atomic nuclei that have a
slightly less mass slightly less total
mass in the system and that mass equals
MC² is energy. So extremely high
temperature extremely high speed. Uh
maybe that's one of the other
differences also with fusion and fision
is just the amount of temperature
required for the reactions. Is that
accurate to say? Yeah. And I think
fundamentally it's that in a lot of ways
fusion is hard and fision is easy.
>> Nuclear fision happens at room
temperature. That this uranium and
plutonium is so likely to break apart
already that simply the adding of one of
these neutrons, one extra particle will
then break it apart and release energy.
Um and if you have a lot of them
together, it will create a chain
reaction. Fusion, that doesn't happen at
all. Fusion is actually really hard to
do. You have to overcome those
electromagnetic forces to have a single
fusion reaction happen. Um and so it
takes things like in our sun we have
what is called gravitational confinement
where the gravity literally the mass of
the fuel itself is pulling to the center
of the sun and it's pulling in there. So
there's a large force that's pulling all
that fuel together and and and holding
it and confining it together such that
it gets close enough and hot enough for
long enough that fusion happens. And
then we have to figure out if we're uh
building fusion reactors, we have to
figure out how to do that confinement
without the huge
uh size gravity of the sun. That's
right. Obviously, the sun is vastly
larger than Earth and so we can't do
that same process here on Earth
>> yet. No, I'm just kidding. I But we have
other forces we get to use. We can use
the electromagnetic force, which the sun
doesn't get to do, to apply those
forces. And I actually want to take a
pause right there and point out a word.
Historically, we've used the word
reactor around fusion, but I don't think
that's right. And for me, we're really
careful about this terminology. Um, when
we look to how that word is defined, and
we can look to how the experts define
it. It doesn't really apply to fusion.
Um, so the Nuclear Regulatory
Commission, the NRC, uh, defines reactor
as I have it. I have it right here. A
nuclear reactor is an apparatus other
than an atomic weapon designed or used
to sustain nuclear fision in a
self-supporting chain reaction. And
there's two big parts to that. That one
fision reaction, obviously fusion is not
that. We've talked about why. But also
the self- sustaining part in that a
reactor is self- sustaining. You take
your hands off of it and it keeps going.
In fusion, that doesn't happen. And uh
and we know cuz we have to do it every
day. And it's really hard to do. And so
we actually use the word generator
because you we don't talk about for
instance a natural gas reactor is that
if you stop putting in fuel, it turns
off. And the same thing happens in
fusion. And so we'll we're we're pretty
careful about making sure we talk about
that as a generator where you're putting
in fuel, you're getting electricity out.
Um and then when you stop putting in
fuel, it just shuts off. And you can go
even one step further and say, "What am
I going to do with this fusion that
powers the universe?" And what does
humanity want out of this? And what we
want is electricity. We don't simply
want a set of reactions um or even heat
and energy. That's great. But what I
really want is electricity. And uh yeah,
we'll talk about the technical details
of one of the big benefits of the linear
design of the approach that you do is
you get to electricity directly as
quickly as possible. And some of the
other alternatives
um have a intermediate step and those
again are are technical details. Let me
sort of still linger on the difference
between fusion and fision. Uh what are
some advantages at a high level of
nuclear fusion as a source of energy?
>> Fundamentally as as a source of energy.
In fusion you're taking these
lightweight isotopes, you're bringing
them together. You're releasing energy
and that energy is in the form of
charged particles. It's already in the
form of electricity. Fusion itself has
electricity built into it without a lot
of the steam or thermal system
requirements. And so that's a really
nice fundamental benefit of fusion
itself. Also, this reaction that's
really hard to do turns itself off. So
you end up with that fusion is
fundamentally safe. And that's really a
key requirement of any industrial system
is that it turns itself off and is safe.
You turn the key off on your car, you
know it's going to turn off. I guess the
the flip side of that, just sort of
stating the obvious, but it's nice to
lay it out for nuclear fision, it's uh
chain reactions, so it's hard to shut
off. And it works by boiling water into
steam, which spins turbines and produces
electricity. Can you talk through this
process in a nuclear fision reactor? In
a nuclear fision reactor, you put enough
of this fizzile material, uranium or
plutonium together such that as these
unstable molecules, these unstable atoms
crack open and break apart, they release
heat that the component parts of those
are actually quite hot. And so, not only
are the component parts that the uranium
breaks into, and it's a whole spectrum
of different atoms and atomic nuclei are
hot, but it also releases neutrons. It
also releases more of these uncharged
particles. And if you do it right, this
file material will be next to other
fizzile material. And so that neutron
will then go and bombard another uranium
nucleus again opening that up and
releasing more heat and more of these
neutrons. And that's how you have those
reactions of a self-supporting chain
reaction. And that chain reaction then
continues. People design fision reactors
such that you have just the right
balance of enough neutrons are made such
the reaction is continuing but not so
many neutrons are made that it speeds up
cuz you don't want it to speed up.
>> And there's some kind of cooling
mechanisms also like that's part of the
the art and the engineering of it.
>> And then the key is at the same time you
want to make sure that the whole thing
is in water is typically the cooling
fluid. There's some more advanced fision
reactors that have different cooling
fluids, but water typically where then
that absorbs that both the heat and
those extra neutrons. And so you use the
water and the fluid to then run a steam
turbine to do traditional electricity
generation and and output electricity
through your your steam turbine. You end
up with complicated systems of flowing
liquids and flowing water, balancing the
heat. A lot of fision reactor design
comes from that thermal balance of
keeping this reaction going, making sure
it doesn't speed up because that's
that's an un uh controlled chain
reaction which you would not want and
balancing the the cooling and the output
of getting the water out of it. So we
should say that for reasons you already
laid out maybe you can speak to a bit
more is nuclear fusion is much safer. So
there's no chain reaction going on. you
can just shut it off. But it should also
be said that as far as I understand the
current fision nuclear reactors are also
very safe. I think there's a perception
that nuclear fision reactors are unsafe.
They're they're dangerous and if you
just look empirically at the statistics
that the fear is not justified by the
actual safety data. Can you just speak
to that a little bit? Yeah, we've been
talking about the reaction processes
themselves, but I think fundamentally
let's take a step back and look a little
broader and say, let's look at what we
care about, which is the power plant
making electricity. And I look at this
from a nuclear engineer's point of view.
I spent a lot of years studying these
these systems. Um, and modern vision
reactors, I believe, are are engineered
to be safe. They're engineered in ways
where as those uh reactions maybe speed
up and those systems get hotter, they
actually are built to expand and cool
down passively and natively. And there's
protection systems in place that modern
systems are quite safe from an
engineering perspective. And so I
believe that we have figured out how to
build nuclear fision reactors in a way
where the engineering of the power plant
is safe. I would say that I look back at
the history of what we've built over
time and the challenge hasn't come to
the engineering. Actually, I believe the
engineers have solved these problems. Uh
the problem comes from humans and the
problem comes from other things around
nuclear power. You have to enrich that
uranium to put it in a plant and the
plant's safe, but you had to enrich that
uranium and that is some of the problem.
or a plant is designed to run for a
certain number of decades safely, but do
we run it longer than that? And so those
are where I think the real challenges
happen is more with the humans around
these systems than the engineering of
the power plants themselves.
>> Well, I have to ask then uh what do you
think happened in Chernobyl? What
lessons do we learn from Chernobyl
nuclear disaster and maybe also three
Mile Island and Fukushima accidents? I
think you're suggesting that it has to
do with the humans a bit. So with
Chernobyl and Fukushima, I actually put
Three-Mile Island in a different
category. In fact, um some of the recent
news in the last year is that we're
going to be restarting Three-Mile Island
because there's such a need for clean
base load power. So that's that's
actually a very interesting other topic
we should talk about is is why and and
how we're doing that. But more than
that, going back to the accidents that
did happen, um, in both of those
systems, you can point to the human
failure rather than the engineering
failures of those systems that in
Fukushima specifically, there were
multiple nuclear fision reactors on the
same site that successfully kept running
through the tsunami totally successfully
and were only later shut down for more
political reasons. But the old one, the
oldest of them that had been on site for
for long periods and maybe maybe too
long, I think some experts have looked
at this in the past, um was where the
some of the problems actually happened.
And so I look to that less as a um
a failure of the engineering of the
power plants and more of the humans and
around those systems that if we that we
should be operating these plants as
designed and and then I believe they're
safe and that gets to some of the atomic
weapons questions that I think are the
other part around nuclear reactors and
fision reactors that are concerning for
me. Can you speak to those? So maybe
this is a good place to also lay out the
difference between nuclear fision
power plants and nuclear fision weapons
and maybe also nuclear fusion power
plants and nuclear fusion uh weapons
like what are the differences here?
fusion power plants can't be used to
make nuclear weapons like fundamentally
that the the processes in fusion aren't
the same processes that happen in
nuclear bombs and nuclear weapons and so
it's actually one reason I started in
fusion and most of our team thinks about
the mission of fusion of delivering
clean safe electricity is that also
can't be used to make weapons and I
think that's a little bit of a
distinction from traditional nuclear
fision reactors is that while I totally
believe as a nuclear engineer you can
you we build power plants now that are
safe that aren't going to have reactions
they use a fuel uranium and plutonium
that can be used to be made to make
nuclear weapons that we know that if you
take enough fizzile material together
enough uranium plutonium put it in a
small volume that it will not just
create a reaction but it will create a
supercritical reaction that will then
continue and grow and release a
tremendous amount of energy all at once.
And that is a bomb. That is a bad
situation. And that is what we want to
avoid. A lot of the key is recognizing
that even though there are things called
fusion bombs, the H bomb, the hydrogen
bomb, the hydrogen bomb has uranium in
it, it's still a fision bomb. And so how
this fundamentally works is that you
have a fision reaction, a primary, and
that creates radiation that induces a
fusion reaction with a small amount of
fusion fuel that then boosts that
uranium reaction again. And so most of
the energy, in fact 90% of the energy in
an Hbomb is all still from the uranium
reactions themselves. Yeah, I think
people call it sort of the nuclear
fusion bomb, hydrogen bomb, but really
it's still a nuclear fusion bomb. It's
just that fusion is a part of the
process to make it more powerful, but
you still need like you said the uranium
fuel. So, it's not accurate to sort of
think of it as a fusion bomb really. And
if you take away that that fizzile
material that that nuclear fision
reaction, the fusion reaction doesn't
happen at all. Um, in fact, there's been
researchers that have over the decades
tried to make an all fusion bomb and
been very unsuccessful at it. The
physics and the engineering don't
support it can ever happen with our
understanding today. The topic we're
talking about is more broadly called
proliferation. And this is the creation
of nuclear weapons in the world and the
distribution of those weapons. And
something we know as physicists and
engineers is that fusion can't be used
to make nuclear weapons. We know that.
But that is not sort of widely known.
And and part of what we went out to do
is work with the proliferation experts
in the world, the people who work to
prevent nuclear weapons from being made,
being created, being shared throughout
the world because we know the challenges
that the geopolitical challenges that
happen. And we went to those
proliferation experts and we were
worried they would have the sort of the
same historical question of like well
it's it the word nuclear is in fusion so
therefore it must be related and and in
fact the total opposite happened. What
they told us is please please go develop
fusion power plants absolutely as fast
as possible. The world needs this. And
the proliferation experts were telling
us that otherwise people would start
enriching uranium throughout the world
and we'd be building enriched uranium
power plants because we need the
electricity that's clean and base load.
But in those processes, they'll be
making fuel that could be one day used
for atomic weapons for nuclear weapons.
And they were worried that that that the
growth of this enriched uranium, think
about the centrifuges, that having a lot
more centrifuges happening all over the
world would lead to more weapons, at
least the possibility of it. And so they
are pushing us as fast as possible. Go
build fusion generators and get them
deployed everywhere. Not this just in
the United States, but all over the
world so that we're building fusion
power and and that's meeting humanity's
needs, not this other thing. And so I
was really pleasantly surprised. We've
written a number of papers and worked
with those communities um on this of
what does it mean? How is fusion power
safe and can't be used for nuclear
weapons? So this might be interesting to
ask on the geopolitics side of things. I
have the chance to interview a few world
leaders coming up. By way of advice,
what questions should I ask world
leaders to figure out the geopolitics of
nuclear nuclear
proliferation, nuclear weapons, nuclear
fision power plants and nuclear fusion
power plants? What's the in interesting
intricate uh complexity there that you
could uh maybe speak to? The question I
would want to ask is what would you do
if we could deliver for you lowcost
clean industrial scale tens or hundreds
of megawws of fusion power that's
lowcost clean base load and doesn't have
the geopolitical consequences of uranium
and plutonium of file material.
What would you do there? How would that
change your view of the next 30 years?
>> But also, there's a lot of geopolitics
connected to oil, natural gas, and other
source of energy, which I think are
important in Saudi Arabia, in the Middle
East, in Russia,
uh, I mean, all across the world. And
that's interesting, too. So, do you
think actually if everybody has nuclear
fusion power plants that alleviates some
of the geopolitical tension that have to
do with energy, other energy sources?
>> I certainly do. that the fuel is in
seawater all over Earth. Everybody has
dutarium
>> and everybody has it and so you can't
have a monopoly on the fuel
>> and no one can control the fuel and no
one can turn off the fuel, no one can
cut a pipeline like that just cannot
happen with fusion. And so if we can
deploy those plants and we can deploy
them quickly, then it it decouples the
ability of any one or any few countries
to control energy.
Okay, so let's sort of return to the
basic question. We already mentioned it
a little bit, but is nuclear fusion
safe?
So the power plants that we're talking
about, fusion power plants, uh are they
safe? Yes, fusion power is fundamentally
safe. The physics and the reactions of
the fusion system itself means you don't
have runaways. And so we've talked about
some of the human factors around power
plants and PL power systems and
industrial scale systems. Um and that's
something that we build into the design
of these from today. Um we look at uh
how these systems might fail. And in
fact, some of the analysis we do is um
we did this analysis for the Nuclear
Regulatory Commission over the last few
years looking at how do you regulate
fusion power? As we're building the
first fusion power plant, we need to
make sure we're regulated safely. And so
we spent a lot of time doing the
technical case and the political case in
the United States of how to regulate
fusion.
Um and so the analysis we did is assume
you have a fusion power plant that's
operating and then at any one time a
meteor strikes it. The whole thing is
vaporized. What is the impact of that?
So this is worse than you could ever
imagine an actual physical scenario. But
let's start there. Um and the answer is
you don't need to evacuate the populace
nearby the fusion power plant. Um and
one of the keys I think that I come to
when I think about this is the fuel in
that in a fusion generator you are
continuously fe feeding in this hydrogen
these dutarium fuels and at any one time
in a helon fusion system and most fusion
systems you have 1 second of fuel in
that system. And so what that means is
if you stop turning on if you stop
putting fuel into that system, fusion
just stops. But what also means is that
if something really catastrophic
happened and for whatever reason, um you
have all of that fuel that's not in the
system and fusion is so hard to make
happen, you hit it with a meteor, you do
anything of in that nature and fusion
doesn't happen. That hydrogen, that
heavy water, that dutarium just goes
back into the environment safely and
cleanly without without issue. And so
that's the fundamental safety mechanism
of fusion. And you can compare that with
other types of power plants, oil or a
coal power plant. You might have a large
pile of coal that then catches fire and
burns. And it's not catastrophic, but
you have a large coal fire for a long
time releasing toxic fumes that you may
have to deal with. Um, and in nuclear
power, an efficient power plant, you may
have several years of fuel sitting in
the core. And in that case if something
bad happened you have all that potential
energy of for for uh things to happen.
But in fusion you have literally 1
second of fuel at any time in the
system. And having a tank of dutarium
which we have around all the time can't
do fusion by itself. It needs that
complex system. I love that there's like
a powerpoint going on in a secret
meeting about like what happens if a
meteor hits a fusion power plant. Okay.
So that's really interesting. Uh what
about the waste? what kind of waste is
there for uh fusion power plants?
>> So the fusion reaction itself is still
fundamentally an atomic reaction. And so
during this reaction, you do create
ionizing radiation. You create X-rays,
you create neutrons, and you create all
these charged particles. Um the charged
particles themselves for a fusion
reaction are all contained in the the
fusion system. Um and the X-ray is
similar to think about dentist office
although a lot more than that but that
type of same X-ray and X-ray energy is
absorbed by the fusion system but the
thing we do care about is those neutrons
and so we do have in a fusion system
activation we have during its operation
neutrons are made and leave and so we
have to shield these fusion systems
during their operation. Um and so this
is very similar and in fact this is a
lot of the work we did with the nuclear
regulatory commission over the last
number of years um that there was a
landmark agreement that happened for the
NRC that then was codified into law last
year called the advance act which is
really powerful because it says for the
very first time how the US government
leading the way on this which I'm really
proud of will regulate fusion and this
gets into a little bit of the details
but the way the nuclear regulatory
commission regulates nuclear things in
the United States is in these different
sets of statutes and nuclear reactors
are regulated under something what's
called part 50 and there's a lot of
variety of the regulatory language
around that but most of it is to handle
special nuclear materials uranium and
plutonium but fusion is not fusion is
regulated under something called part 30
and part 30 is how hospitals are
regulated particle accelerators other
types of irradiators where as they're
operating, you have very high energy
particles ionizing radiation and you
have to protect operators from it and
you have to shield them. And so we build
concrete shields and if you came and
visited Helion, you would see uh plastic
bored polyethylene and concrete
shielding um to protect operators and
equipment from the fusion reactions
while they're happening. Um but again,
you turn them off and those fusion
reactions stop and that's really the
key. Um there's a funny uh story related
to that. We um sto we've been building
fusion systems that do fusion a long
time and at some level we they got
powerful enough doing enough fusion we
started building these shields and and
shielding them like a particle
accelerator. Um and I went to the uh
regulatory bodies that regulate part 30.
This is in Washington state. It's the
department of health. And so I went to
the department of health and said,
"Here's an application for a fusion
generator shielding permit um as a as a
particle accelerator." And um uh the
very first question I got asked was
great, where do the patients go? Because
the standard form had a patient uh as a
hospital, the patient dose for the
particle accelerator, and then the
shielding. And we talked all about the
shielding and the operators, which is
very similar for a helon system. And we
said, "No, no, no patients at all. No
one's inside this thing. Our goal is to
generate electricity one day. This was a
lot of years ago. Um and and we were
able to go through and work with state
agencies to license these fusion
particle accelerators. We were as far as
we know the first licensed fusion system
ever. Um as a particle accelerator for
those first systems. Um first license we
had was in 2020. Um we then have gone on
and now licensed several of our fusion
systems that we've built that do fusion.
both the shielding as well as um some of
the the fuel processes.
>> So high level what are the the different
ways to build a nuclear fusion power
plant?
So can you explain what a takamacha is,
what a stellarator is and what's the
linear approach that uh helon is using?
So there are a number of ways to do
fusion. Um and fundamentally in all
fusion approaches you're trying to do
the same phys same fundamental physical
process which is take these lightweight
isotopes heat them up so that they can
um move at high velocity over 100
million degrees. Bring enough of them
together. We call it density. enough of
them together in a certain volume so
that you have reactions happening um at
a higher rate and keep them together
long enough that they are able to
collide into each other and do fusion
and release energy. Um that's the
fundamental core. Now how you do that,
how do you bring those particles
together, how you hold them together
long enough, there's a wide range of
technologies that as humans we've been
exploring um since the 1950s.
And I think about several main
categories. If you look at the fusion
funding out there, government funding in
the world, private funding actually has
quite a different uh profile which is an
interesting thing to talk about. But in
public funding and federal funding in
the United States, there's two mainline
programs called inertial fusion and
magnetic fusion. And in inertial fusion,
what you're trying to do is bring
together and push together by a variety
of means, physical means, those
particles. You push them together. The
most common is called laser inertial
fusion. Our colleagues at the National
Ignition Facility did this really well
and made world records in the last few
years for being able to demonstrate you
can do this and do it at scale where you
take very high power laser lasers and
pulse them together to combine them to
do fusion for a pulse for a very short
period of time nanoseconds billionth of
a second. the other extreme and you
mentioned tokamax and stellarators.
Stellarators are actually my favorite.
So we'll we'll talk about those graduate
student infusion. The stellarator is the
first thing you learn about
>> because there's a mathematical solution
for a stellarator that solves perfectly
>> and and um and and you can write it out
and you can solve it and analytically
it's very simple. building one is very
hard. And so it's taken uh humanity a a
number of decades to be able to build
stellarators. And we can do it now. Um
with the Windstein 7X that came online
uh in the last few years being the
premier uh stellarator in the world. I
should say all the different ways to do
fusion all just looks so badass in terms
of engineering
creating this containment extremely high
temperature high density everything's
moving super fast everything is
happening super fast it's just
fascinating that humans are able to do
like there's certain things accelerators
of that a little bit but this is even
cooler because you're generating energy
that can power humanity with this
machine anyway way. Can you just speak a
little bit more to the inertia in the
magnetic fusion systems?
>> In a magnetic system, your goal is not
to
push together those particles as fast as
possible. Your goal is to hold on to
them for as long as possible. And to do
that, we use magnetic fields. So, let's
take a step back. What is a magnetic
field? So, in an electromagnet, um
there's a variety of ways to make a
magnetic field. One of the most famous I
think everyone is familiar with is Earth
itself. Earth has what we call the
magnetosphere which is the magnetic
protection that's generated actually by
the core of the earth. But we have a
magnetic field around the earth and that
magnetic field protects us from
particles coming from the galaxy
galactic cosmic rays and solar particles
that would come to earth. That magnetic
field when you run a compass you see the
magnetic field from the earth. So we
know it's happening. It's all over. But
how we generate it with electric
currents is a little bit different. And
what we do is that we have a loop of of
wire. And the simplest way to think
about it is literally a round loop. And
in that loop, you have electrons. You
have an electrical current that's
running. And when electrical current,
this is some of Maxwell's equations that
we discovered in the 1800s that when you
have an electrical current in a wire, it
generates a magnetic field inside that
wire. And so when you look at fusion
systems, uh, you always have these big
magnetic coils with large amounts of
current. We don't run a little bit of
current. In our systems, we have
hundreds of mega amps of current. If you
think about at your house, you have your
um, uh, breaker box with 200 amps or
maybe a 400 amp breaker box. And we run
100 million amps of electrical current.
So massive amounts of electrical current
to be able to do this. Um, so that
magnetic field that's generated inside
that magnetic coil has some really
special properties and and we take
advantage of those properties to do
fusion. And some of those properties are
not intuitive. So here's here's one of
my favorites. When you have an
electromagnetic field, you have this
coil with electricity going around it
and you have a magnetic field inside of
it. And then you have a test particle, a
charged particle, an electron or an ion,
which is if you imagine to generate
this, I have a coil with electrons
moving around it. But if I put one in
the middle of it in this magnetic field,
some really interesting things happen.
That electron or that ion, that charged
particle is what's called magnetized.
And what magnetized means is that it's
trapped on that field line. In fact,
even really more interesting is that it
oscillates around that field line. And
so the way I think about this is if you
think about the Earth's magnetosphere
again and you think about the charged
particles, the aurora, the the northern
lights, is a charged particle trapped in
the Earth's magnetic field going around
the Earth's magnetic field. And in the
same way in fusion we do the same thing
here on earth but in a smaller direction
where we trap these particles on
magnetic fields and they can go around
and stay attracted to that magnetic
field line. How much of the physics
at this scale is understood here? Like
how these systems behave when you when
when you um trap the magnetic field in
this way like is this fundamentally now
an engineering problem or is there a new
physics to be discovered about how the
system is behaving in in fusion? The
physics we're using is actually quite
old that the fundamental electromagnetic
physics is 1800's physics. The
fundamental atomic physics is early
1900s. And so the fundamental physics of
how these work is very well understood.
Putting them all together into a power
plant, that's hard. And so you can do
the math. You can do the math. Every uh
introductory grad student does the math
on a stellerator and say this is all I
need to do. Um I just need to make a
magnetic coil in this very complicated
shape and then fusion will happen. Um,
however, doing that in practice is
actually quite quite challenging.
>> So, maybe you can speak a little bit
more. So, the the accelerator and the
TOK, what's the difference between those
two? They're both magnetic fusion
systems. And then what is helon do?
>> The tokamac and the accelerator are both
magnetic systems. Their goal is to
generate this magnetic field and hold on
to the fusion fuel long enough. Like I
mentioned, these charged particles are
trapped on the magnetic field. In fact,
they're oscillating. We call that a gyro
orbit as the radius that they oscillate
around this magnetic field. Um, and
we're we've been talking about atomic
physics where everything is uh at this
nano scale. But gyro orbits are not gyro
orbits for these fusion particles are
measured in inches. And so they're
they're in on a scale that that that we
can see and measure and and understand
really intuitively. Um, and in a
magnetic system, your goal is to simply
trap as many of these particles as you
can for long enough that and heat them
so they're hot enough so that they bang
into each other. They collide enough
that you're doing fusion and you're
doing enough fusion to overcome as fast
as you're losing those particles. And so
that's what what happens when you put
particles in a magnetic field and you
try to hold on to it. The challenge is
that's really hard to hold on to them
long enough. These particles are moving
around. They're moving at very high
velocity. millions of miles per hour.
They're colliding with each other and
they're getting knocked off and getting
knocked away. So, we've talked about
inertial fusion where you try to confine
a fusion plasma by crushing it as fast
as possible and magnetic fusion where
you just simply have a magnetic field
and your goal is to hold on to it for as
long as possible. But there's another
way to do fusion and in some ways it's
one of the earliest approaches for
fusion that was successful. Um, as
scientists and engineers, maybe we're
not too creative with the terminology.
We call the technique that Helon uses
magneto inertial fusion because it does
a little bit of both. So to understand
that, we can actually go back in history
a little bit and think about the
evolution of some of these approaches to
fusion. And so from our perspective, we
look at the technology that we use as
built on physics experiments that were
very successful in the 1950s. Um and in
those systems the earliest pioneers of
fusion said I know we understand the
physics we have to take these gases heat
them to 100 million degrees and then
confine them push them together so that
fusion happens and so what is the best
way to do that? So the some of the
earliest programs we called them the
theta pinch and what those programs were
were a linear topology because we knew
how to build these magnets. It's called
a solenoid where you take a series of
electric coils. You run electrical
current through them that generates a
magnetic field. Great. So, you have a
magnetic field. Now, you add your fusion
particles. Okay? So, you've added fusion
particles to this solenoid. Here's the
challenge. Those particles as they're
sitting in that magnetic field in this
nice magnet escape. They leave out the
ends because there's nothing holding
them in. Great. So, that makes sense.
Um, and so that doesn't work. Okay. So
then the next approach I say, well, one
one branch of fusion said, "Okay, well
to solve that, why don't we take this
solenoid and bend it around? Let's just
make it a big donut." So as they're
escaping, they go around and around in a
circle. Great. That's a great approach.
And so one branch of fusion went down
that direction.
And and that became that evolved into
the stellarator and the tokamac.
different ways of taking those solenoids
and wrapping them around so that the
plasmas go around and round in that
magnetic field and are those charged
particles are held long enough that
fusion happens. But there's a different
way to do it. And so the theta pench was
what was born in the 1950s of take this
magnetic field and oh they're trying to
escape. Great. Let's not let them
escape. Let's close the bottle.
>> Let's close the ends. And so we make the
magnetic field much stronger at the
ends. This one was called the mirror.
And so the idea was that the the
particles would bounce in between. And
that worked and they got hotter and
hotter and hotter. But guess what? As
you kind of would imagine, as this
mirror topology, this linear topology,
the pressure increased inside the the
particle pressure, the the particles
trying to push back on the magnetic
field. They were trying to escape. Now
they're trying they're getting hotter
and hotter. And just as you imagine, hot
gas in a balloon tries to get out the
ends. and you could not hold it tight
enough at the ends to keep those
particles in. And in fact, the problem
is the hottest ones were the ones that
would escape.
>> And so you do a good job of heating it
and they'd all leave out the ends. Okay?
>> So then the next iteration is said,
"Okay, well, why don't we just not try
to hold on to it very long, why don't we
squeeze it?" And so rather than just
holding it constantly, let's now crush
it. So we built this solenoid. We
pinched the ends and then we crushed it.
And when what I mean by crushing it is
not actually like crushing any magnets
or changing the the the topology or or
moving any parts, but just rapidly
increasing the magnetic field. And so
going from a magnetic field that's just
holding it to now taking all those
particles, if you imagine they were in a
a streaming around together and then
rapidly increasing the magnetic field so
that those particles get closer and
closer and closer together. So you
increase the density and now fusion
starts to really