
ITER: World's largest nuclear fusion project begins assembly - goodcanadian
https://www.bbc.co.uk/news/science-environment-53573294
======
usui
I am going to need some help on this one as my knowledge on physics is
limited: What makes scientists believe that the solution to nuclear fusion
power is only a matter of scale? I desperately want nuclear fusion to work
because nuclear power is the only realistic way to solve the looming energy
crisis of the 21st century while still maintaining the same standard of living
for everyone. It's also 500% more important that nuclear fusion works because
most people around the world think that nuclear fission is scary
(weaponization concerns even though fission power is different from bomb-
making, radioactive waste, reactor meltdowns, etc.), even though it's the only
realistic method we have today of going carbon-neutral.

However, I looked up the article on "fusion power"
([https://en.wikipedia.org/wiki/Fusion_power](https://en.wikipedia.org/wiki/Fusion_power))
and it says "but to date, no design has produced more fusion power output than
the electrical power input, defeating the purpose."

Can anyone help explain what I am missing, or what is not explained well? My
common-person impression is if a laboratory experiment cannot even produce
desired outcomes, what makes people think that an engineered, faulty-prone
system will? The way I see it is that researchers produce the proof-of-
concept, and engineering will attempt to reproduce that at scale. Isn't this
preemptive? Or, from the article, it seems that it is necessary to build this
thing in order to get any conclusive research results.

~~~
andrepd
I'm also a fusion power fanboy but

>nuclear power is the only realistic way to solve the looming energy crisis of
the 21st century while still maintaining the same standard of living for
everyone

This is just not true, there's no way you can say this. Solar costs are going
down massively. Hydro is dirt cheap already. So renewables can absolutely be
part of an energetic transition in the near future, while fusion is at best
many decades away. So while I think fusion energy has the potential to
transform energy generation, and by extent everything about our life, it's
wrong to assume renewables aren't probably our safest bet in the near future.

Also there's something amusing about "Here's my sure assessment. Anyway I
checked the wiki page on fusion power and".

~~~
jjoonathan
Hydro is actually pretty bad in terms of big safety incidents (Banqiao: 171000
dead, Machchu: 5000 dead, South Fork: 2208 dead) and solar/wind have trouble
beating nuclear on metrics like death/watt because you need lots of
infrastructure per watt. Picture a few large cities with contractors running
around every roof tending to solar panels and compare to a few experts at a
single nuclear power plant. For the contractors-on-roofs, the slip & falls add
up even though they'll never get an HBO mini-series.

Anyway, I tend to agree that going forward solar + storage is probably
workable. The storage part isn't proven yet but I have faith we'll figure it
out. There are lots of promising options under investigation and the proven
fallbacks aren't _that_ horrendously expensive, all things considered.

It's just a pity we stopped building nuclear 40 years ago because it was
viable all the way back then. Heck, we got to 20% nuclear! Compare to 2% solar
today. If we had merely continued building nuclear at the same pace instead of
stopping in the 1980s our grid would be 100% low-CO2 _today_ instead of maybe
30 years from now if we hurry. But that didn't happen. We made the super-
mature and responsible decision to fill our atmosphere with CO2 instead and
now we get to live with that decision. So it goes.

~~~
jpdus
> Picture a few large cities with contractors running around every roof
> tending to solar panels and compare to a few experts at a single nuclear
> power plant. For the contractors-on-roofs, the slip & falls add up even
> though they'll never get an HBO mini-series.

This is a very flawed and short-sighted argument. Averages don't matter when
you are talking about fat-tailed/power law risk distributions. Nobody would be
opposed to PVs on roofs in their neighborhood b/c some construction workers
fall to death every year - this risk is well calculable. But (almost) everyone
would be opposed to a fission plant or nuclear waste facility next door - and
rightfully so.

Without enormous direct and indirect subsidies, nuclear (fission) isnt
commercially viable anywhere in the world. Heck, you still can't insure a
fission plant.

Yes, in theory fission would have been the best option for carbon-free energy.
No, in practice humanity never figured out how to safely and efficiently use
this power source and now renewables are a way safer and cheaper bet. You
won't find any objective economic analysis (that incorporates such indirect
subsidies as the implicit state guarantee and realistic building and waste
handling/storing costs) that can show otherwise.

~~~
arkh
> But (almost) everyone would be opposed to a fission plant or nuclear waste
> facility next door - and rightfully so.

Reading this kind of debate from France is a good laugh.

If you're interested you can check where our electricity comes from here:
[https://www.rte-france.com/eco2mix/la-production-
delectricit...](https://www.rte-france.com/eco2mix/la-production-delectricite-
par-filiere) (between 60 and 70 percent of nuclear energy today).

~~~
worik
Because France was desperate to have its own nuclear weapons.

It was not economic for them either (tho back in the day it displaced coal -
try having a coal plant next door)

~~~
philipkglass
France's nuclear power program actually displaced _oil_. France had a lot of
oil fired electric power plants in the 1960s when it was a cheap fuel. As a
reaction to the oil price shocks of the 1970s, France committed to the
"Messmer Plan" for nuclear electricity:

[https://en.wikipedia.org/wiki/Nuclear_power_in_France#Messme...](https://en.wikipedia.org/wiki/Nuclear_power_in_France#Messmer_Plan)

France demonstrated its first fission bomb in 1960 and its first thermonuclear
bomb in 1968:

[https://en.wikipedia.org/wiki/France_and_weapons_of_mass_des...](https://en.wikipedia.org/wiki/France_and_weapons_of_mass_destruction)

The 1970s and 1980s build up of nuclear power in France had nothing to do with
desperation to have its own nuclear weapons. France already had them before
the Messmer Plan.

~~~
worik
"France's nuclear power program actually displaced oil"

No. Oil is _much_ cheaper

To maintain a nuclear arsenal a nuclear industry is needed.

It is the only economic justification for nuclear power

~~~
iso8859-1
So you don't think something can be expensive because it is heavily regulated?
Or do you just think it is not possible with less regulation?

------
gautamcgoel
I think fusion is cool, but I also think it distracts from more important and
promising approaches to clean power. No one has ever demonstrated a self-
sustaining, net positive fusion reaction. It will probably take >30 years to
make this technology cheap , safe and reliable and another >20 years to deploy
it at scale. We don't have 50 years to wait on clean energy, we need it today.
We should be focusing our attention on renewables, like solar, which are
rapidly dropping in cost, and good 'ol nuclear power, which is already proven
to be safe and reliable, instead of crossing our fingers and waiting for some
magical tech to save us. We already have the tech, we just need to get serious
about deploying it. I bet a concerted roll-out of nuclear + solar could cut US
emissions due to electricity generation by at least 30% over the next 20
years.

EDIT: I see this is getting some downvotes. I want to reiterate that I support
fusion research, I am just saying that I don't believe fusion is the quickest
or most realistic approach to reducing emissions.

~~~
usui
I do not think solar is going to work. As you say, it might take up to 50
years to crack the case on nuclear fusion. I argue that it might take up to 50
years for governments and companies around the world to even begin cooperating
in a fashion such that they make a dent in carbon-based energy sources at the
global scale using solar.

The reason why solar is not going to work mostly is because there is no
legitimate mass installation of batteries that can handle the demand of
energy. And the reason why the batteries cannot handle the demand of energy is
because governments are not serious about deploying more, and people are
already comfortable with the quality of life they already have, so neither are
going to step up to make this work. And to be fair, why should the average
citizen impose restrictions on themselves to solve this crisis? It's not
realistic. Governments are supposed to be the ones to make these initiatives.
Analogy: I hate having to pay for taxes, but I like that the government gets
it from everyone, so that it can implement common services that benefit a lot
of people, which wouldn't be possible otherwise.

The only way is nuclear fission because, as you said, it is proven to be safe
and reliable. However, the people have spoken: They do not want "dangerous"
nuclear reactors around, even if those impressions were formed by reactors
designed and built in the 1950s-1960s. I personally think this is a shut case.
There is no convincing of the people to go to nuclear fission anymore.

~~~
svara
It's a bit odd to me that you seem to deem fusion power realistic, while
discounting other ways of generating and storing power that are basically
available already.

Power from renewables can be stored for the long term as hydrogen. That's well
understood technology, scaling up is an engineering problem. When the sun
shines and the wind blows, solar and onshore wind are the cheapest ways to
make electricity, so there's a huge economic incentive to solving the storage
issue.

~~~
usui
Thanks for pointing out, because now that I think of it, my view does come off
as odd. What I think it reflects is that despite nuclear fusion being a
technical, engineering problem, I believe getting companies/governments to
abandon carbon for wind/solar to the point of carbon-neutral is even more
insurmountable. Does that viewpoint make sense? For them to get off fossil
fuels, it's going to need a ball-out-of-the-park solution. It's too hard to
compete with the fracking revolution.

~~~
nicoburns
Why do you think economic incentives won't be enough? Solar and wind are
already the cheapest energy sourve in terms of production. We just need large
scale storage to become cheap and practical and we're sorted.

The UK government has committed to being carbon neutral by 2050. That's well
before you're even prediciting the fusion becomes available.

------
gclawes
At this point I've got a lot more hope in the MIT/Commonwealth Fusion Systems
approach with REBCO magnets:
[https://www.youtube.com/watch?v=L0KuAx1COEk](https://www.youtube.com/watch?v=L0KuAx1COEk)

At this point it looks like ITER is hampered by it's relatively old
supeconductor technology (ultra low temp/moderate field strength traditional
magnets vs high temp/high field REBCO magnets).

~~~
sam
ITER and Commonwealth can (and in my opinion should) be seen as complimentary
endeavors.

ITER has been designed with relatively conservative magnet technology and will
very likely provide the physics results that need to be understood in order
for fusion power to become a reality. This includes experimental tests of the
physics of plasmas where the heating is dominated by high energy alpha
particles rather than external heating. This is a regime that's not yet been
studied in a laboratory and there is important research to be done there.

Commonwealth is pushing the envelope of high temperature superconductor magnet
technology and is relatively high risk compared to ITER's magnets (and this is
a good thing). Lots of ITER technology will be useful to Commonwealth even
before ITER turns on. For example decisions about which low activation steels
and the huge amount of physics work that's already gone into planning for
ITER.

I think the most likely outcome is that both accomplish their goals and
contribute to making commercially viable fusion energy a reality in the
future.

------
kristianp
18b doesn't seem like a huge amount of money these days with the economic
stimulus funds being announced around covid-19.

~~~
bjackman
For some reason I often think about things like this in terms of NHS budgets.

18bn is, very roughly, 2 years of healthcare for London.

~~~
nikanj
Or like three pre-launch startups

~~~
jansan
I don't even want to know how may Aeron chairs you could buy for that money.

------
eximius
It is hard for me to conceive of the steps required in these projects that add
up to years - just in assembly.

Is it due to precision requirements being difficult to achieve? Supply chain
delays for custom parts? Lots of experimental runs that require dis-assembly
and tuning?

~~~
the8472
One part of it is that it's a research project. The other part is the
bureaucracy of international cooperation and the pieces being built all over
the world according to a huge centrally managed specification. It's not like
SpaceX that starts with a small design and then builds incrementally larger
versions to have something to show in the meantime. It's from 0 to finished
product.

~~~
pezezin
I'm currently working for IFMIF (sister project of ITER), and I know some
people who work or worked for ITER, and yes, the bureaucracy is an absolute
nightmare. Coordinating so many countries with so many different working
cultures is really difficult.

On the other hand, we DO build incrementally larger versions. The machine is
built and tested in stages, it would be impossible to build such complex
machines in just one go.

~~~
the8472
> On the other hand, we DO build incrementally larger versions.

You're referring to JET? Does ITER benefit from production facilities that
were used for it?

~~~
pezezin
First of all, I'm just a computer guy who joined this field two years ago. I
still don't know much, so please excuse my ignorance.

Regarding JET and ITER, according to what I heard from my coworkers, all the
knowledge that was gained at JET is being used for ITER. I guess many of the
productions facilities are being reused too, but I would need to ask them.

Regarding our project (IFMIF), we are building a linear accelerator to
simulate the neutron flux inside a fusion reactor and study the behavior of
different materials. The accelerator is composed of an injector, several
acceleration stages, and a beam dump. First the injector and the beam dump
were installed and tested, and then all the other stages are being installed
and tested incrementally. But a linear accelerator is a very different machine
from a tokamak.

~~~
the8472
I'm asking because afaik (and that's fairly superficial knowledge) is that JET
is mostly a european project while ITER is built internationally and the
production is intentionally assigned fairly (to spread experience to
contributors) rather than with a focus on efficiency. So that implies to me
that there would be many new manufacturing places all over the globe. In other
words it's made from scratch, more or less.

------
irthomasthomas
I'm surprised that we're still chasing moon shots in strong force fusion,
while weak fusion, which has actually been demonstrated already, gets little
attention. Chemically assisted/low energy nuclear reactions have been proven
to produce clean energy and useful transmutation. This process can be used to
turn radioactive waste into inert material. For example, technetium-99 is a
particularly pernicious by-product of nuclear fission. It has a half-life of
~200,000 years and is very mobile in the atmosphere, making it difficult and
expensive to handle. In a CANR reactor, this nuclear waste is converted into
the safe, and valuable, palladium-106, and the by-product is clean heat. Given
the double benefit of clean fuel and nuclear waste recycling, I think this
should be a bigger priority than strong-force fusion.

[http://nautil.us/issue/86/energy/einsteins-lost-
hypothesis](http://nautil.us/issue/86/energy/einsteins-lost-hypothesis)

[https://www.jstor.org/stable/24216601?seq=1](https://www.jstor.org/stable/24216601?seq=1)

[https://www.sciencedirect.com/science/article/pii/B978012815...](https://www.sciencedirect.com/science/article/pii/B9780128159446000130)

~~~
karxxm
So you suggest that they should dump nearly 2 decades of work because there is
something else which seems to be a potential energy source? The ITER project
was founded in 2007. From there on hundreds of physicist, chemists, engineers
and computer scientists started planning this RESEARCH project in order to
better understand this kind of technology. Shouldn't we stick to what we have
started (since this is (more than) cutting edge technology) and have a look at
other technologies in parallel?

~~~
undreren
> So you suggest that they should dump nearly 2 decades of work because there
> is something else which seems to be a potential energy source?

OP said nothing of the sort. They said that they didn't understand the
prioritization of funding given an alternative that they found personally much
much more valuable.

~~~
karxxm
I am pretty sure that this project is not prioritized in any way. It's a
research project with funding from all over the world. It should be compared
to the CERN project where scientists from all over the world try to understand
science behind it better. One could argue that CERN is a waist of money since
there are other fields of study in physics which seem to have more potential.
We should be happy that states from all over the world are willing to pay for
a research project, which does not have a direct "value" for the next couple
decades. There will never be a private investor for this scope of project
since there is no monetizable value behind it yet and maybe in the next 50
years.

~~~
undreren
No one claimed the opposite.

------
erik_landerholm
From Here:
[https://drive.google.com/file/d/1p6jrlbUOuuOCHnhR9fcsvnQJl4d...](https://drive.google.com/file/d/1p6jrlbUOuuOCHnhR9fcsvnQJl4dJeKPF/view)

"Most of the power (~100 MW on ITER) released in SOL flows in an extremely
narrow channel ~1 mm"

wow

~~~
lambdatronics
Yeah, steady-state heat fluxes comparable to re-entry are expected.

------
OptionX
Sorry I'm a layman at best on the subject, buts whats the difference between
this project and, for example, W7-X?

~~~
petschge
To get fusion there is a couple of ways: There is gravitational confinement
(that is how stars do it, but it is impractically large for humans), there is
inertial confinement (get enough energy out before it explodes, but that only
works for hydrogen bombs and NIF, not for a reactor) and magnetic confinement
(that is what we intend to use for reactors).

Magnetic confinement works because a plasma consists of charged particles that
gyrate around the magnetic field lines. So (to first order) they can not
escape across field lines. But they can move along the field lines and hit the
end of the device. The particles move fast, so simply making a linear device
long enough is hard. So the next idea was to bend the magnetic field into a
torus (the shape of a donut), because that way there is no end to the magnetic
field lines. Unfortunately that configuration is unstable, the plasma donut
will bend and twist until it hits a wall, stops being a plasma and falls to
the ground. There is basically three option out of this problem:

1.) Tokamaks [1] such as ITER. Here we induce an additional current inside the
plasma that goes around the hole of the donut. That produces a small
additional field that stabilized the current. But driving that current can be
hard (using what is called a plasma transformer work only for a limited times,
but AFAIK that is not the first limit on a discharge that ITER will hit, wall
heating limits single plasma "shots" to shorter times anyway). The upside is
that the design is rather simple, which implies you don't need millions of
core hours to design and the fields coils are reasonably easy to produce.

2.) Stellarators [2] such as W7-X. Here the field coils that produce the field
lines in the donut are intentionally twisted to produce a more complicated
magnetic field. The upside is that we do not need the current in the plasma
and get better performance (for a device of similar size), but the design of
the field coils is hard (impossible back in the 60ies and still really hard
even with modern computers) and the production of the coil is not simple
either. You can actually include "producability" as an optimization goal along
with plasma performance in your design code, but even then you will have to
build a large number of different coil designs.

3.) Active control. It takes some time for the plasma donut to bend and twist.
Typically a few milliseconds. So if you stick a large number of sensors and
computer controlled coils around the plasma you might be able to continuously
keep the plasma confined, just like balancing a pencil on its tip. This was of
course utterly unimaginable back in the 60ies, and even today there is mayor
problems. Sensors aren't fast enough, optimal (or even good) control
algorithms are unknown and rapidly ramping megaamperes in the control coils is
hard if you don't want to rip them out of the device accidentally. And you
probably only have ~ 10 failed attempts before the wall of the vacuum device
is compromised and you need a new device. Consequently there is some small
scale research on that (sorry I don't have a cool link handy), but nobody is
trying that on large devices for now.

[1]
[https://en.wikipedia.org/wiki/Tokamak](https://en.wikipedia.org/wiki/Tokamak)

[2]
[https://en.wikipedia.org/wiki/Stellarator](https://en.wikipedia.org/wiki/Stellarator)

~~~
willis936
I work at HSX and “produceability” is really a set of three or four
constraints. Picking their relative weights in optimizers is still in the
“art” category because we simply don’t have the computational resources needed
to search all spaces with all simulated plasma parameters. A flux surface is
optimized with the preferred model of the day, then coils are optimized to
this surface. A few good candidates are chosen then the realized flux surfaces
are calculated and plasma parameters simulated. It’s very far from the ideal
plug-n-chug that it could be, but these models are also incomplete and benefit
from people understanding them. We simply need people tending the machines if
we want to make a better stellarator.

On that front: keep an ear out for an HTS stellarator in the next decade.

------
StanAngeloff
Some years ago, likely around 2010, I had the priviledge to visit Culham
Centre for Fusion Energy (it was called UKAEA Culham back then). During my
visit, we were shown around various experiments and after a long evening, we
had the opportunity to attend a Q&A with the staff. The question everyone
wanted to know the answer to was When will it be ready? The scientists and
everyone else involved honestly thought 10 years would be more than enough
time for the technology to mature and find its way into everyday lives.

Commercial fusion energry, always 5-10 years away.

~~~
AQuantized
About 15 years ago my physics professor told me fusion would always be 20
years away, so at least we're getting progressively shorter times away.

~~~
ajakate
Reminds me a little of this xkcd on the James Webb delays:
[https://xkcd.com/2014/](https://xkcd.com/2014/)

------
lambdatronics
I have such mixed feelings about ITER. I hope we learn the things we want to
from it, and that what we learn is good news. But ITER is very far from being
a demonstration of a practical power plant -- it's a science experiment first
and foremost. (Well, it has _really_ been an experiment in international
government cooperation...)

I'm concerned that fusion research could have an 'AI winter' if there are any
problems with ITER. (Similar to what has happened to inertial fusion in the
failure of NIF to achieve ignition.) On the bright side, I think
Commonwealth's SPARC experiment has a chance of beating ITER to hit
'scientific' break-even (Q>1) -- although ITER should top out around Q=10-20,
where SPARC is aiming for Q~4. (Q~20 is needed for a power plant.)

The issue of 'disruptions' (rapid unscheduled disassembly of the plasma) has
not been solved. ITER's construction was premised on the idea that we need it
to be solved, so therefore it will get solved. The situation is very similar
to that of self-driving cars -- avoiding 90% of disruptions seems pretty
doable, but a percent or so happen without
warning.([https://fusion4freedom.com/pdfs/Disruption-Risk-poster-
Wurde...](https://fusion4freedom.com/pdfs/Disruption-Risk-poster-Wurden-
LAUR.pdf))

I hope that people don't get the wrong idea about fusion from ITER. Fusion
reactors don't scale down well, but they also don't have to be quite as large,
slow, and expensive as ITER. Tokamaks only use about 10% of the available
magnetic field pressure, which means about 100x less power density than is
theoretically possible, for a given magnetic field strength. Also, ITER is
limited by its superconductors to about 5T. REBCO superconductors could
potentially triple that, which would increase power density 81 times. So,
there is a ton of headroom to improve performance -- dealing with the outflux
of power becomes the major issue, actually.

Ultimately, fusion is a long way from market still. It's hard to innovate
rapidly with devices that cost billions and have life-cycles of decades.
Private enterprises are pushing down on those numbers, though -- that's where
I'm pinning my hopes. Given that renewables are approaching grid parity, it
looks like the goalposts will start receding before fusion even achieves net
power production.

------
saberience
Dumb question here, but how is the actual power transmitted to the grid? I get
we are trying to have some sustained reaction with plasma inside a magnetic
field... but that just makes heat, not electricity.

Other reactor types have water to heat up and make steam but where does this
happen in a Fusion reactor? It seems as though there is no obvious "place" for
there to be water to turn into steam.

Again, sorry for dumb question.

~~~
nucpal
It's not a dumb question.

The answer is kinda dumb though, most working fusion reactors don't have a way
to extract heat yet. But the plan is to use the same turbine (heat water into
steam) technology from fission reactors. So you have cutting edge plasma
physics in one part of the reactor and old school victorian-era steam turbines
in the other.

~~~
imtringued
So it all boils down to boiling water?

~~~
0xffff2
We really only have a few ways to generate electricity:

\- PV solar generates electricity more or less directly

\- Wind turbines use mechanical energy from the wind to spin a turbine

\- Hydro converts potential energy to kinetic energy to spin a turbine

\- Nearly every other form of generation in existence heats water to create
steam and uses that steam to spin a turbine.

------
tus88
Finally! I have been following this for over 20 years and thought it would
never happen.

~~~
jeffbee
And you were probably right!

------
ratdragon
What does HN crowd think of companies like hb11 or lppfusion which try to
construct much smaller but still powerful (lpp plans for 5MW, relatively
small, reactor. They also want to use a different fuel that produces very
little neutrons, thus very low radiocativity. And moreover they do not need
thermal part as electricity is generated by directly collecting alpha
particles (and some Xrays IIRC). It _feels_ to me like ITER is inheritance
from old times - trying to build the reactor the way we always did (i.e.
thermal; and also using the "easiest" to ignite fuel - but that produces a lot
of radiocativity compared to hB11 fuel). As someone pointed out here in
comments, there are already better magnets than those used in ITER even now.
Don't get me wrong, it would be sooo cool if ITER succeeded and started fusion
energy generation, but it is just taking too long.

    
    
      https://www.hb11.energy/our-story https://lppfusion.com/technology/fusion-energy-generator/

~~~
fluffything
I worked on Gene - a gyrokinetics app used to study fusion reactors - and I
fondly recall helping a colleague debug one of their simulations in which they
set a boundary condition incorrectly; that simulation ran for two weeks before
the mistake was found. We estimated this mistake to have costed the tax-payer
multiple millions of dollars _in electricity costs_ (just from the core's that
were used, their wattage, and the time duration; which is a fraction of the
cost of acquiring and operating a super-computer).

All our fusion models that correctly predict all the results produced by all
the fusion reactors that have been built to date predict that ITER will work.

I have no idea whether these models predict that these other reactor designs
will also work. What I do know is that one needs _many_ simulations to study
that, and the costs of doing that feels absurdly out-of-reach for any startup.
One does not only need to "verify" a design, but come up with it, optimize it,
etc. as well as gaining access to the supercomputing resources or buying and
maintaining their own supercomputer. That puts the initial investment already
in the millions.

OTOH, a startup that checks a design that has been created, optimized, and
verified in academia and whose goal is "only" to build it, would require a
smaller investment, but no idea how big this investment ought to be.

------
wiz21c
FTA : "Iter is a collaboration between China, the European Union, India,
Japan, South Korea, Russia and the US. All members share in the cost of
construction."

Who contributes how much ? Because at face value this sounds like real
international (that is, beyond little war games) cooperation. Sort of
"mankind" project.

~~~
swebs
>Europe [The member countries of the EU, not the entire continent] is
responsible for the largest portion of construction costs (45.6 percent); the
remainder is shared equally by China, India, Japan, Korea, Russia and the US
(9.1 percent each). The Members contribute very little monetary contribution
to the project: instead, nine-tenths of contributions will be delivered to the
ITER Organization in the form of completed components, systems or buildings.
In this way, the scientific and industrial fabric in each Member is prepared
for the step after ITER—the conception and realization of the type of
prototype fusion reactor that will demonstrate industrial-scale fusion
electricity within this half of the century. For all Members, the potential
benefits of participation are significant: by contributing a portion of the
project's costs, Members benefit from 100 percent of the scientific results
and all generated intellectual property.

[https://www.iter.org/proj/Countries](https://www.iter.org/proj/Countries)

------
throwawaysea
ITER won't be commercially viable. After ITER comes DEMO, which is itself a
decades-long project. DEMO won't demonstrate electricity generation until
2048:
[https://en.wikipedia.org/wiki/DEMOnstration_Power_Station#Ti...](https://en.wikipedia.org/wiki/DEMOnstration_Power_Station#Timeline)

In my mind, that means we need to see deployment of Gen 4 fission reactors
([https://en.wikipedia.org/wiki/Generation_IV_reactor](https://en.wikipedia.org/wiki/Generation_IV_reactor))
commercially, to bridge the gaps between a decline in coal-fired plants and
the potential of renewables.

~~~
pfdietz
There probably has to be a machine before DEMO to solidify the engineering and
materials.

Also, after ITER, there will not be enough tritium to do another large machine
(the tritium comes from heavy water reactors, but those have lost in the
market and will be shutting down in the next couple of decades.) So a machine
to just make tritium may be needed.

------
pfdietz
Looking at stories like this, you need to realize how far out of the running
this technology is.

The power density of ITER (gross fusion power of the reactor divided by the
volume of the reactor, not just the volume of the plasma) is 50 kW/m^3. This
is horribly low, about 1/400th the power density of a PWR reactor vessel.

The power/$ is also horribly bad. The cost is going to have to come down by
two orders of magnitude to start being competitive.

Fusion is an example of sunk cost thinking. The only reason we're working on
it is because we had been. A clean sheet energy strategy would put very little
resources into fusion.

~~~
lambdatronics
Solar was 2 orders of magnitude out of the running around 1975 -- and now it's
at grid parity. So maybe fusion is 45 years away? :P

You're right that the cost is going to have to come down, and the power
density up, before fusion can compete. High-field superconductors are one
obvious route, and using plasma configurations that make better use of the
magnetic fields are another. Either one of those approaches could deliver
about two orders of magnitude in power density -- and they could be combined.

>The only reason we're working on it is because we had been.

I think there's been an element of that in the way the federal program has
been run, but claiming it's the _only_ reason to pursue fusion is not
defensible.

~~~
pfdietz
That approach doesn't work, because reactor power density becomes limited by
wall loading (neutron and/or thermal), regardless of how good the plasma
physics is.

It's the square cube law. At a given wall loading limit the volumetric power
density is inversely proportional to the linear dimensions. And a DT fusion
reactor must be meters across, due to the fixed cross section of the neutrons
with wall materials. In contrast, fission fuel rods are 1 cm in diameter and
are closely spaced, so the available surface area for heat transfer is much
higher (neutrons in fission are also much less of a problem, since they carry
a much smaller fraction of the energy output and are of much lower energy, on
average.)

(I think the only hope for DT fusion is something like LINUS, where the entire
first wall is thick flowing liquid lithium.)

> I think there's been an element of that in the way the federal program has
> been run, but claiming it's the only reason to pursue fusion is not
> defensible.

What is the other reason? I cannot find any other plausible justification.
This is particularly true now that fission is out of the running. Fusion used
to be justified by "it won't be too much more expensive than fission, but it's
safer and won't run out of uranium." That argument is now pointless.

~~~
lambdatronics
>the entire first wall is thick flowing liquid lithium

Yeah, I agree on the liquid walls. I think the optimum might be to have a thin
Li first surface flow that is relatively cool, then a shell of SiC, and behind
it a PbLi breeding blanket that can be at higher temperature. There's a trade-
off because the first-surface can't be made too hot or the evaporation will
pollute the plasma, but getting high thermodynamic efficiency means using
higher coolant temperature. The thickness of the liquid first-surface plays
into the lifetime of the SiC shell -- more shielding in front of it means
longer life (so lower maintenance costs & higher reactor up-time, and less
radwaste), but lower thermal conversion efficiency on average.

There are problems of course -- corrosion by Li, splashing of droplets into
the plasma, MHD drag & pump power requirements, incompatibility of lithium
with many forms of sensors & actuators for plasma control.... (OTOH, most
sensors and actuators can't tolerate radiation anyway, so fancy control
techniques just don't stand a chance in a reactor anyway. We need boring,
stable plasma configurations that just sit there and work.)

>What is the other reason?

Some people think they can make a fortune :D

------
ragebol
What downsides are there to fusion power, assuming it's commercially viable in
a couple of decades? What negative externalities are there that could make it
prohibitive? Fossil fuel has pollution etc, solar takes up lots of space and
is apparently also ugly, wind energy is ugly and makes noise (according to
NIMBYs).

What argument could a NIMBY person have against fusion power, besides the big
building in their back yard?

~~~
lambdatronics
Radioactive leaks/accidents -- they will be orders of magnitude less of a
problem than fission, in the worst case, but people are innumerate, so they'll
still object.

------
pl-94
Can someone explain to me the advantages of fusion over fission? Except for
the radioactive wastes and the enthusiasm of journalists I don't get it

~~~
nucpal
It's mainly the waste.

Nuclear fission is a stable source of energy that does not produce carbon
emissions in production. It's pretty much the answer to the climate crisis
except that it produces dangerous waste that is horrendous to store and
manage.

Fusion mainly avoids this :)

~~~
pl-94
OK but some models of gen iv of nuclear power plants can pretty much do the
same. It sounds pretty dumb to me that journalists are super enthusiast about
fusion but much less about gen iv (which is way more mature)

~~~
nucpal
"some models of gen iv of nuclear power plants can pretty much do the same"

I'd be interested to know which fission plants make fuel recycling and waste
disposal trivial, I could make a lot of money!

In reality, even the gen 4 plants that have interesting approaches to
reprocessing still produce a lot of harmful radioactive waste. Not all the
fuel can be recycled and the process itself is imperfect and messy.

------
antpls
To have a sense of scale, it would be super cool if someone could make a photo
montage with some aerial pictures from
[https://www.iter.org/album/Media/4%20-%20Aerial](https://www.iter.org/album/Media/4%20-%20Aerial)
and some other big known structures.

Maybe one of the Tesla Giga factory on top of the same picture (correctly
scaled of course) ?

------
yalogin
I thought Lawrence Livermore laboratory does some cutting edge experiments on
fusion and I read articles about how they are hoping to get some breakthrough.
Is this new thing supposed to actually help take the tech forward or achieve
something we havent achieved so far?

~~~
l0b0
From the about page[1]:

> […] prove the feasibility of fusion as a large-scale and carbon-free source
> of energy […]

[1]
[https://www.iter.org/proj/inafewlines](https://www.iter.org/proj/inafewlines)

------
zionpi
“We hope to see first plasma in five years. That will only be a short plasma -
lasting a few milliseconds” this is a quote from original article.I was
wondering why `few milliseconds` can make such a huge impact?What does this
`few milliseconds` plasma mean?

~~~
lambdatronics
You gotta start somewhere! The plasma discharges will eventually last several
minutes, but they will 'exercise' the machine very carefully/gradually over
the course of a few years to be sure that nothing breaks.

------
Jenz
Those magnets are huge.

I wonder if, though possibly solving the problem of clean energy, it will also
create other problems, say, something like "geomagnetic field pollution".

------
JumpCrisscross
Is there a good single compendium of ongoing fusion projects?

~~~
sam
Yes, check out
[https://www.fusionenergybase.com/](https://www.fusionenergybase.com/) which
I've put together. List of organizations are here,
[https://www.fusionenergybase.com/organizations](https://www.fusionenergybase.com/organizations)
and individual projects are here,
[https://www.fusionenergybase.com/projects](https://www.fusionenergybase.com/projects)

------
iandanforth
Is Iter aiming for breakeven or net plus energy?

~~~
jansan
One objective is a Q value of greater than 10 for a moment. And a steady Q
value of 5.

Source:
[https://en.wikipedia.org/wiki/ITER#Objectives](https://en.wikipedia.org/wiki/ITER#Objectives)

~~~
The_rationalist
_Maintain a fusion pulse for up to 8 minutes_ What does this mean?

~~~
throwaway744678
My understating of the issue is that one need to keep the plasma is the
adequate state for 1\. the reaction to occur (i reckon we can do that for a
fraction of a microsecond or something) 2\. make it self-sustaining (we're not
here yet) 3\. Obviously without producing an H-bomb. Neighbours might get
unhappy.

~~~
throwaway0a5e
> 3\. Obviously without producing an H-bomb. Neighbours might get unhappy.

If you do it wrong enough the neighbors won't even know.

------
transfire
ITER is nothing more than a money sink to underfund innovative research in
fusion power.

Big Oil ️ ITER.

------
LockAndLol
So many fusion sceptics in the comments that it sounds like a congregation of
anti-vaxxers. Funding for fusion has been ridiculously low for decades and
it's exactly because of sceptics with myopathy like the ones present here.

Countries could've been pumping trillions into fusion and other clean energy,
together, for years, but we'd rather vote for politicians willing to bomb the
oil out of a poorer nation than think more than a decade or more ahead. Now
that climate change is finally becoming more of a reality, the myopathic
sceptics are turning into temporal sceptics "but we won't have enough time".
People like them create the issues we have and every time a solution is
proposed, they'll cast doubt.

I'm glad things are moving along at all. I say stop oil, petrol, gas subsidies
in every country, and get out of countries you all shouldn't be sticking your
noses in. Invest in something that will actually let your grandchildren
inhabit a planet with less friction and a much smaller threat to their way of
life (climate change, overfishing, plastic pollution, etc.). Stop being so
selfish.

~~~
pfdietz
The equation of fusion skeptics to anti-vaxxers is an unacceptable slur. We
have excellent and incontrovertible evidence of the efficacy and value of
vaccines. We have no evidence that fusion can be made practical, and there are
well understood arguments for why it will not be.

Fusion is more like the Emperor's New Energy Source, an exercise in groupthink
and sunk costing.

------
thinkloop
Fusion + AI = no more human labor

~~~
Semiapies
And always perpetually 20 years away.

~~~
adventured
Harnessing the perpetual motion required for it to always be 20 years away, is
the key to fusion being able to generate infinite energy at a low cost. It's
the most challenging aspect.

------
mbgerring
> The facility could see plasma generated in the machine - a notional start to
> operations - shortly after the assembly phase ends in 2025.

So you're saying it's... 5 years away?

~~~
qwertox
The generation of plasma is approximately 5 years away.

Around 2035 the first experiments with tritium will me made, at least that's
the expectation.

And even then ITER isn't designed to be a usable reactor, it's just a
prototype. They intend to build a real one afterwards, and even that one will
be a demonstration reactor.

~~~
Normille
With all this talk of the colossal ITER project merely being a warm-up for the
even bigger DEMO one to follow which, in its turn will be but a pre-cursor to
the real thing, I can't help being reminded of Douglas Adams's 'Deep Thought'

 _“There is no problem,” said Deep Thought with magnificent ringing tones. “I
am simply the second greatest computer in the Universe of Space and Time.”_

 _“But the second?” insisted Lunkwill. “Why do you keep saying the second?
You’re surely not thinking of the Multicorticoid Perspicutron Titan Muller are
you? Or the Pondermatic? Or the . . .”_

 _Contemptuous lights flashed across the computer’s console._

 _“I spare not a single unit of thought on these cybernetic simpletons!” he
boomed. “I speak of none but the computer that is to come after me!”_

 _Fook was losing patience. He pushed his notebook aside and muttered, “I
think this is getting needlessly messianic.”_

 _“You know nothing of future time,” pronounced Deep Thought, “and yet in my
teeming circuitry I can navigate the infinite delta streams of future
probability and see that there must one day come a computer whose merest
operational parameters I am not worthy to calculate, but which it will be my
fate eventually to design.”_

------
aey
P != NP will be proven before we have a breakeven fusion.

------
rini17
The elephant in the room: fusion is no better wrt radioactive waste than
fission. ITER is projected to end up with 30000 tons of radioactive waste.

[https://thebulletin.org/2018/02/iter-is-a-showcase-for-
the-d...](https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-
drawbacks-of-fusion-energy/)

"Surrounding the ITER tokamak, a monstrous concrete cylinder 3.5 meters thick,
30 meters in diameter and 30 meters tall called the bioshield will prevent
X-rays, gamma rays and stray neutrons from reaching the outside world. "

~~~
nucpal
That article is quite outdated, JET has 2020 D-T campaign.

More importantly, fusion is a thousand times better than fission with respect
to waste.

No one is claiming there is no waste at all, but tritium has a half-life of
12.5 years so most of the waste will be safe within a few decades. The rest
will largely be neutron embrittled steels/materials (classified as low level
nuclear waste) that is easily stored.

Compare and contrast that to nuclear fission which generates high level waste,
spent nuclear fuel rods and radioactive liquid which must be painstakingly
petrified and processed before safe storage. Even then this waste will still
be dangerous for over 100,000 years.

~~~
rini17
So the waste output/power output is 1000 times better? Any sources pls?

And this "Neutron embrittlement" does not create any dangerous long-lived
isotopes? Like, we just wait few years and then normally landfill the concrete
or how should I imagine the process?

~~~
nucpal
Fission creates neutron embrittled materials and steels as well. And yes we
tend to store them until they can be safely disposed.

Again, the main difference is the fuel. Tritium is safe in a few decades,
spent uranium is safe in a few hundred thousand years.

