Delivering Fusion Energy
thank you
um so i’m a physicist you can probably
guess that there’s not many times i’ve
followed on cheerleaders
and i was watching them backstage and
they were absolutely phenomenal my heart
was racing
anyway um so yes i’m here to talk to you
today about
fusion energy this is not about me this
is about an idea
and hopefully by the end of the talk uh
you’ll be as convinced as i am
that that idea is uh is a worthy cause
um before we get on to that
let’s talk about the cheery subject of
climate change
now when i think about climate change
um i tend to adopt a similar manner to
this gentleman here and i’m sure many of
you
in the audience feel a bit the same and
i think the reason is
that it’s a very intangible subject it’s
a big
broad problem that will take millions of
people
over tens of years to solve and it’s
very hard for us to really
put that into context i’ll try and do
that here a bit for you
let’s so our goal should be to
decarbonize our energy supply we need to
not
rely on carbon-based fossil fuels to
produce energy
how do we do that or what does that
actually mean last year
globally we burnt 11 billion tons of oil
or 11 billion equivalent tons of oil
so if we want one year of
energy supply without carbon in our
energy
economy we need to displace 11 billion
tons of fossil fuels that’s the
challenge we’re facing
now we have there are innovations
underway to do this
um renewables renewables are fantastic
and they will definitely definitely play
a role
uh in the future the problem is with
renewals is reliability
what happens if the sun goes out we’re
very familiar with that here in the uk
what happens if the wind dies what
happens if the tides go out
we can’t rely on renewables for
continuous power supply we need to do
better and what we would really like
is a source of energy that is clean that
is safe
and that is continuous now luckily
mother nature has provided one for us
this is fusion fusion is the process
that powers the sun this is the sun
um we can see it today uh luckily i had
a lovely joke prepared
for just in the event that we couldn’t
see the sun today but i’ll leave that
one for next time
so fusion is the process by which two
very very small
atoms hydrogen in the case of the sun
move around
come in contact with one another bond
and form a new atom
uh in this case helium and because that
helium is
slightly less sways slightly less
than all of the parts that went in to
make it we can use equals mc squared
the most famous equation in science and
we get energy back
out of that and that’s fusion energy now
we’ve known about fusion for a little
while so fusion pioneer
sir athlete arthur stanley eddington
said in 1920 when he was describing this
energy
this resource can scarcely be other than
the subatomic energy which exists
abundantly in all matter
we sometimes dream that humanity will
one day learn how to release it and use
it for their service
the story is well nigh inexhaustible if
only it could be tapped
now at the time this was met with some
skepticism because people very quickly
realized that you needed intense
pressures
intense temperatures to get this to work
we do not argue with the critic he says
who urges
that stars are not hot enough for this
process we tell them
go find a hotter place now
eddington died in the 1940s and it’s a
real shame that he’s not around today
because actually we do know that in the
universe
there is a hotter place where we can be
reasonably certain that fusion does
occur
and it’s here in south oxfordshire this
is our lab in a little town called
column in south oxfordshire
and this in this building when it’s
running we have a machine called jet and
it is the hottest place in the solar
system
now the sun is a relatively inefficient
fusion reactor
which is very good because otherwise it
would have burnt out billions of years
ago and
we wouldn’t be in this pro in this mess
anyway but we need to do better here on
earth so we don’t use hydrogen we use
deuterium
which is one proton and one neutron and
this fuses
with tritium which is one proton and two
neutrons
and the byproduct of that is helium two
protons two neutrons
and a lonely neutron now this neutron
flight carries a huge amount of energy
with it and it flies out of the vessel
and will eventually heat some sort of
water blanket around a machine
drive a steam turbine now these fuels
are very abundant so about one in every
six thousand atoms of hydrogen in water
is actually deuterium
so you you take a bath in deuterium
tritium on the other hand is not very
abundant in nature it’s radioactive so
it doesn’t occur naturally
but we can make true tritium out of
lithium if we bombard lithium with
neutrons
we can make tritium and it turns out
that if we take all of the deuterium
in one bathtub of water all of the
lithium in one laptop
one laptop battery we’ve got enough
fusion energy there
to match 40 tons of coal or 250
kilograms of uranium
quite a lot this is enough to power your
home for 20 uh
40 years or 20 years if you’re an
american um
and to put it into more uk perspective
it’s enough to make
2.7 million cups of tea
now the most uh developed fusion reactor
that we have on earth is called the
tokamak
the tokamak uh was a device that came
out of russia in the 1950s and 60s
as you might have guessed from the name
up there that i’m not going to try and
pronounce
and the tokamak basically consists of
three key parts
at the center of the machine we have
something called a plasma now if you
take a gas and you heat that gas to
super high temperatures
all of the electrons in that gas are
going to split off from the atoms
and you’ve got a super of electrons
flying around ions flying around
interacting with each other
but no longer forming atoms that is a
plasma actually
plasmas are really really common so
something like 40 uh 97
of all matter in the known universe is
actually in the plasma state
um so we have a plasma at the center of
our machine it’s burning
at 150 million degrees and we have to
keep it there somehow
now because everything in the plasma is
charged
it reacts to a magnetic field and we can
use that to our advantage
so we place magnetic field coils all
around the machine that
um that apply a kind of magnetic cage to
this plasma and keep it in place
now that’s all well and good but we
don’t want to do that in the air
because air contains lots of nasty
things like oxygen
so we don’t want to use air so we keep
everything in
a vacuum and this is basically what a
tokamak is it’s a plasma
in a vacuum vessel housed in a magnetic
cage
now we’ve known about tocomax for about
50 or 60 years
and we’ve sunk a lot of money worldwide
into this research
and you as taxpayers except the students
in the audience
you would be well within your rights to
ask
why don’t we have fusion now where is
fusion well actually we’re very lucky
that we
can finally say that fusion is entering
the delivery era
this is eta eta is currently being built
in the south of france
and ita will be the proof of principle
eta is a 35-year collaboration
between seven partners china the eu
india japan south korea russia and the
united states
about 50 percent of all of the world’s
population is represented in ita and
about 90 percent of the world’s economy
is represented anita so it’s a massive
massive scale project
it’s costing 25 billion euros which is
as much as five
large hadron colliders or one house in
inner city london
eta is monumental in every respect it’s
about the same size as a football
stadium the whole complex
the magnets anita can levitate an
aircraft the heating systems in eta
could vaporize a car in seconds it
really is in every respect
pushing the technological capabilities
of mankind right to their very limits
so why are we doing it eta will produce
10 times the power
out from fusion energy than we put into
the machine so we’re going to multiply
the energy we put into this machine by
10 times
which is great but more importantly it
is going to produce something we call a
plasma burn
and a plasma burn occurs when the heat
inside the plasma is enough
to keep that reaction sustained so we he
we
chucked some heat into the plasma some
fusion happens
and it self heats and it keeps itself
going
and once we achieve that the
possibilities are pretty much
endless as long as we can keep this
thing contained
now eta is the solution
the problem not the problem eater is the
proof
but eater is not the solution the reason
that eater is not the solution
is because it’s too expensive for the
amount of power it’s producing
we need to do better if we’re going to
build commercial fusion reactors
and we’ve identified six challenges more
or less
that stand in the way block this kind of
commercialization
going from one to six these are we have
to make the hot bits really hot we have
to achieve these burning plasmas at 150
million degrees
we have to build the machine out of
materials that can withstand the
intense environment that we’re putting
them in so this is a really a not nice
environment to be placing materials in
some most of that heat will used will
extract as energy and this is great this
is what we want to do but some of that
heat will remain in the system
and we have to be able to remove that
heat in a safe way that doesn’t damage
the machine
we also have to be able to be
self-sufficient so we have to produce
enough tritium
that we can keep the whole process going
without uh without
sort of fizzling out we say we can do
all of those four things and we’ve
successfully run the machine for six
months
we’re still going to have to repair it
and you don’t want to send people in to
do that it’s not a nice environment to
take a walk around
so we use robots and we have to uh do
all of this through remotely operated
robotic maintenance
and finally if you can do all of that
you will have to do all of that
in sync so you have to do you have to
solve all of those challenges
in a way that marries together and can
work all at the same time using
innovative manufacturing techniques
most of which we haven’t invented yet
this is the challenge that stands before
us
now it’s very nice to be able to stand
in front of you and say we’re addressing
all of these challenges right now and
for the last few minutes of my talk i’d
just like to go through three of them
where i think some really exciting
science is happening right now or will
be happening in the very near future
so i’ll talk a little bit about what
we’re doing to make plasmas burn
i’ll talk a little bit about how we
remove this heat from our systems
and i’ll talk a bit about some of the
robots that are doing the kind of dirty
work that we can’t do
so this is jet jet stands for the joint
european taurus
and jet is based at our lab down in
south oxfordshire and this is the
hottest place in the solar system
at the centre of this machine we’re
burning 150 million degrees
when it’s running at full power jet is
operated by
uh by us on behalf of the european
commission and when it’s running it
looks something like this
so you can see it’s booting up at the
moment and what’s really interesting
about this video
is that when it really kicks in you’re
going to start seeing the video
speckling you’re going to start seeing
pixels
look like something is going a bit wrong
with the camera can you see those there
it’s starting to speckle
now this isn’t the camera going wrong
what’s actually happening here
is fusion born in the center of this
machine is producing the neutrons
which are coming out and they’re hitting
the camera sensor and when those
neutrons are hitting the camera sensor
they’re killing those pixels for a few
seconds and the pixels are dying and
that’s what the speckling is and it’s a
really nice illustration
that we are doing fusion right now on a
regular basis in jet
now jet holds the record for fusion
power um in 1997
it got 65 percent of the power out that
we put in
not one not 10 but still getting close
um and jet is going to be doing these
experiments again very very soon so
at the end of this year at the start of
next year we’re going to be running
a dedicated fusion campaign we don’t
expect to beat
65 so we don’t think jet can do better
than that
but what we will what we do hope to do
is get that 65
but extend it over a nice controlled
range
and once we do that we can say that we
can operate this machine
at its peak performance in a controlled
manner
and that puts us in a really good
position from when for when eta comes
online
so we’re operating jet now really to
prepare us for the eta
um campaigns that are going to prove
that fusion is the energy source of the
future
so assuming that we can do the fusion
and we can create all of this heat how
do you get the heat out safely that’s a
really big problem
and our other machine down in south
orchard mass upgrade
is addressing this so uh matt so to put
this into some perspective
the heat that goes down on the surfaces
in one of our experiments
uh in present-day devices is about the
same heat
that you get at peak performance of a
diesel combustion engine
um working in a climate change field i
should be a bit
embarrassed to say that i drive a diesel
so i can be reasonably assured that that
is a safe
amount of heat to deal with in eta
and in future devices we expect it to go
up to a bit like a space shuttle
re-entering the atmosphere so
quite a quite an intense source of heat
but still something that we can manage
in a fusion reactor we expect it to be a
bit more like an arc welder
anyone done any welding if you have
you’ll know the arc welders are very
good at destroying things
so we do not want a fusion reactor
acting like an arc welder we need to do
something about this
and uh in this machine that you can see
here you’ll see that there are chambers
at the top
and chambers at the bottom of the device
now these are called the super x
diverter it’s a bit of a
fancy name but these are where we’re
diverting all of the excess heat that we
can no longer deal with
inside the plasma and what we’ve done
here is quite clever because we’ve
isolated
the part of the machine that we want to
keep cold
from the part of the machine that we
want to be really hot
so we’ve come up with a design that will
allow us to keep the hot stuff hot
and the cold stuff cold and this is
exactly what we want
if we’re going to operate one of these
things in the future now this is just a
concept at this stage and we’ll be
testing
out later this year if it works as we
expect then we think it should show um
that the concept works it’s a proof of
principle and then we can start looking
at upgrading this concept up designing
this concept
and integrating it into our designs for
future fusion reactors and this is
coming online later this year so look
out for headlines
and finally say we’ve solved this heat
issue and we’ve got burning plasmas
we’ve run our machine for about six
months it’s been all of the materials in
the machine have been exposed to the
most intense source
of high energy neutrons that the world
has ever known
you don’t want to go for a stroll in a
tokamak so
if you have to repair something like say
a pipe you have to do
you have to use robots and this little
animation shows you a robot
going along inside the pipe to a point
that we need to cut
once it gets to its location it’s going
to anchor itself in place
using some ball bearings on either side
and right at the center of the robot
there’s a little laser and in a second
you’ll see this laser rotate around
and it’s going to put a cut into that
pipe just where we need to repair it
now all of these things are operated by
humans but the humans are sitting
hundreds of meters away from these
robots in the nice safety uh in their
nice
armchairs up in a control room somewhere
and all of these things are done
remotely now you can imagine that when
you have to do things with robots even
simple jobs like
cutting a pipe become very very
non-trivial indeed
and we have lots of these jobs that need
to be done in a fusion reactor
once it’s come offline now this sounds a
bit like science fiction
but actually these things are designed
these things work and these things have
been tested and you can see here this is
a little robot
that we have down at the lab and these
are the two little bits of pipe that
it’s cut
so these things are we’re actually
thinking about these questions even
though they’re 40
30 20 years away at the moment we’re
thinking about these solutions right now
we have a center
down at our lab where we’re
investigating lots of these applications
with different robots
and to carry out these tasks that are
absolutely vital
for keeping our future fusion reactors
online
now hopefully i’ve done a good job of
convincing you that the future is fusion
fusion energy will be the energy source
of the future and it’s well worth all of
the time
money and dedication that we put into it
now but you don’t need to take my word
for it
why not listen to stephen hawking so
just before he died stephen hawking was
asked
what world-changing idea small or big
would you like to see implemented by
humanity
that is easy he said it’s not easy
i would like to see the development of
fusion power to give an unlimited supply
of clean energy
and um we’re getting there so
fusion power is still 20 years in the
future but hopefully i’ve shown you that
some of the exciting science we’re doing
right now is on the cusp of making
something like this
a reality a future fusion power plant
producing clean
safe abundant energy for our future
generations
thank you very much