
ITER Tokamak: First Plasma Through High-Fusion-Gain Deuterium-Tritium Operation - ArtWomb
https://www.iter.org/newsline/-/3121
======
Animats
Oh, this is just the plan for 2025-203x. I thought maybe they'd actually got
it running.

~~~
mjfl
What if I told you that even if everything goes perfectly by 2045, ITER is not
a power plant, just a proof of principle? They would have to do further
engineering to figure out how to effectively convert the heat generated into
electricity.

~~~
tim333
I'm not sure if they shouldn't rethink the ITER plan now magnets are much
stronger and build something like the MIT design instead
([https://www.theguardian.com/environment/2018/mar/09/nuclear-...](https://www.theguardian.com/environment/2018/mar/09/nuclear-
fusion-on-brink-of-being-realised-say-mit-scientists)).

There seems to be a bit of a sunk cost fallacy going on at ITER.

~~~
njarboe
ITER is not the route to an economical fusion reactor. The supporters have
even stopped promoting it as such. It is now a research reactor. We may find
out some novel information on how plasma behaves in a certain regime, but this
data is not likely to be useful in building a future reactor. The amount of
resources that have been diverted from fundamental fusion research to be spent
pouring cement and building magnets is a tragedy. We should have a thousand $3
million dollar or a hundred $30 million dollar experimental reactors, not this
monstrosity.

~~~
pas
Scale is everything for fusion (plasma). ITER is very important, as it
represents the current most likely way. (Hence the name.)

That said, it's big, design by committee, slow, meticulous, etc.

It's not a fail fast market-driven experiment.

Also, most of the money is spent on the fundamentals, planning, developing
operational knowhow, basic material science and plasma vessel engineering.

All in all, it could be better, but at least ITER is actually being built.
MIT's ARC is still somewhere between "secured funding for a scaled down
prototype" and actually will build something. Though it's great news, that
they got funding (from Eni, an Italian energy company).

~~~
Tuna-Fish
> Scale is everything for fusion (plasma).

No. Q is everything in fusion. Scale is one way to improve Q in a Tokamak. The
problem with improving Q by increasing scale is that it makes the reactors
uneconomical. A reactor the size of ITER cannot ever be economically viable,
even was capable of producing massive amounts of electricity.

Luckily, scaling up is not the only way to increase Q. The better way is to
use more powerful magnetic fields.

Put more eloquently than I can:
[https://www.youtube.com/watch?v=L0KuAx1COEk&t=43m47s](https://www.youtube.com/watch?v=L0KuAx1COEk&t=43m47s)

~~~
pfdietz
Unfortunately, even with higher magnetic fields, DT fusion is unlikely to ever
be practical. That's because the power density of the reactors is inherently
limited by wall loading and minimum size considerations from neutron cross
sections.

Look at the numbers. The power density of a PWR fission reactor core is 100
MW/m^3. If you consider the volume of the primary reactor vessel instead, it's
20 MW/m^3.

The power density of ITER is 0.05 MW/m^3 (counting gross fusion power). Even
if you just include the volume of the plasma, it's 0.6 MW/m^3.

What about higher field concepts like MIT's ARC reactor? If you look at the
paper on arxiv where details are given, the power density is 0.5 MW/m^3 -- 40
times worse than a PWR.

The low power density is devastating to the economic case for fusion. Magnetic
fusion reactors will be complex, expensive things, with superconducting
magnets, complex cooling systems, breeding blankets, heating and control
systems. They will be much more expensive per unit mass or volume than a
simple PWR reactor vessel. And much of that complex system will need to be
periodically replaced due to neutron damage. If the power density is 40x worse
they cannot possibly compete.

Yes, (SP)ARC is better than ITER. But ITER is so horribly bad that a reactor
can be an order of magnitude better and still not have any real chance of
competing.

~~~
londons_explore
I don't see why the number of cubic meters matters?

If you give me a machine that outputs 50kilowatts, I'll happily give up a
cubic meter of my house for it...

~~~
pfdietz
Because size (and complexity) directly correlate with cost. So unless fusion
can enable cost reduction elsewhere, if the nuclear island is inherently
larger, more complex, and hence more expensive than in a fission plant, power
from it will be more expensive than from a fission plant. And in that case,
why would any utility want one? New and risky (in the sense of having a
significant chance of not working as well as hoped) technologies like fusion
will be adopted only if they are significantly less expensive than more proven
alternatives.

The size and complexity also directly affect reliability. There is more to go
wrong in a fusion reactor than in a fission reactor, and repairing anything
there will be difficult because hands-on work will be impossible.

------
moneytide1
Whatever happened to the German stellarator? Seem to recall Merkel being
present for one of the first tests a few years back, ITER seems to get more
coverage

~~~
sien
It's going really well:

[https://en.wikipedia.org/wiki/Wendelstein_7-X](https://en.wikipedia.org/wiki/Wendelstein_7-X)

It's not, however, something that designed to directly head toward fusion
power itself but instead to better understand components that could be
improved to make fusion power.

In addition now with fusion there are heap of companies trying to get fusion
power going in about a decade or so. Probably the most interesting of which
are:

[https://www.tokamakenergy.co.uk/](https://www.tokamakenergy.co.uk/)

and

[https://www.cfs.energy/](https://www.cfs.energy/)

Who are both using new developments in high temperature superconducting tape
fabrication to increase the magnetic field to get to fusion faster than ITER.

~~~
bdamm
Why not the vortex compression types of "reactors"? a.la
[http://generalfusion.com/](http://generalfusion.com/)

~~~
pfdietz
General Fusion recently gave up on their original design (a spheromak-type
plasma inside an imploding liquid metal vortex.) Instead, they're going to a
spherical tokamaka where liquid metal compresses the plasma from the outside.

In this new concept, there is now a solid wall on the inside that is not
shielded from the plasma by a thick layer of liquid metal. That means power
density limits due to limits on wall loading will apply to their reactor, just
as they do to conventional DT magnetic fusion reactor schemes. So, the major
theoretical engineering advantage of their idea has been lost.

~~~
moneytide1
That was a large Bezos Foundation investment wasn't it?

------
zeristor
The Royal Society held a two day conference 6 months ago if anyone is
interested. They’ve posted the audio files, video would have been nicer but
audio is handy;

[https://royalsociety.org/science-events-and-
lectures/2018/03...](https://royalsociety.org/science-events-and-
lectures/2018/03/tokamak-development/)

~~~
zeristor
With the advent of REBCO superconductors things seem to be in flux.

------
calebh
What about polywell fusion? Can anyone with expertise comment on this design?

~~~
Thorondor
Most mainstream physicists believe that the polywell design cannot work due to
bremsstrahlung and electron cusp losses, as described by Rider. [0] Bussard
and some of his followers have argued against some assumptions made in the
Rider paper, but as far as I know, no one has found any loopholes big enough
to allow a practical, power-producing reactor.

If you're interested in alternative fusion reactor designs, though, you might
want to look into the levitated dipole. [1] There is a lot of evidence
suggesting that this design avoids most of the major problems that plague
tokamak development. [2][3] The remaining obstacles (as far as I can tell,
mainly interchange instabilities and engineering difficulties) don't seem
insurmountable to me. MIT made a serious attempt to build a levitated dipole
reactor in the late 2000's, but unfortunately, the US Department of Energy cut
off all funding in 2011.

[0]
[http://fsl.npre.illinois.edu/IEC/Rider,%20Phys.ofPlasmas1995...](http://fsl.npre.illinois.edu/IEC/Rider,%20Phys.ofPlasmas1995.pdf)

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

[2]
[https://pdfs.semanticscholar.org/92cb/3e1ec34a707b2920f1c03a...](https://pdfs.semanticscholar.org/92cb/3e1ec34a707b2920f1c03a6d1f4f2497d72b.pdf)

[3]
[https://dspace.mit.edu/bitstream/handle/1721.1/95395/99ja014...](https://dspace.mit.edu/bitstream/handle/1721.1/95395/99ja014_full.pdf?sequence=1)

~~~
andrepd
>US Department of Energy cut off all funding in 2011

Sigh.

------
twtw
HN title seems misleading. I read it as ITER has achieved first fusion, when
in fact the news is a revised plan.

~~~
saagarjha
> first fusion

We already have fusion. We just don't have fusion that sustains itself. Unless
this is a specific term that I'm not understanding?

~~~
foobarbecue
No fusion yet at ITER. They've only just started building it.

------
nickik
This is way big of a project. There are so many promising approches, to put
that much money into one very long very expensive mega project.

An international competition with a wider array of technology and more
iterative could have achived more.

If you look how far some organisations get with tiny amounts of funding.

~~~
chriswarbo
Most research advances are either:

\- Small, incremental, predictable improvements, due to more accurate
modelling, tighter tolerances, bigger budgets, etc.

\- Big breakthroughs, usually on shoestring budgets.

The largest impact comes from the latter, but they're very rare and
unpredictable. We might fund thousands of small projects over decades and see
nothing particularly substantial.

Big budget projects are riskier, since we can't fund many of them. Hence these
tend to be the first type of project: where we can be quite confident on the
capabilities and outcomes, so we'll see _some_ improvement; even though it
might not be as promising as the _possibilities_ claimed by umpteen smaller
projects.

It's also easier for individual institutions, companies, countries, etc. to
fund smaller projects themselves. There's no point wading through the politics
required to pool resources into a large international collaboration, if we're
just going to divide up those resources between a bunch of small projects
anyway ;)

~~~
nickik
> The largest impact comes from the latter, but they're very rare and
> unpredictable. We might fund thousands of small projects over decades and
> see nothing particularly substantial.

But that is not the case in fusion. We had many advances in fusion by small
companies.

> here's no point wading through the politics required to pool resources into
> a large international collaboration, if we're just going to divide up those
> resources between a bunch of small projects anyway ;)

I do understand the political problem. However still it could be collaboration
for a contest, rather then organize this project as a multi country technical
problem.

And I would even be happy with just 3-5 projects that get many, many billions
in the end. I mean lets be honest, if it costs $20 billion (and lets be honest
it will be way more) to develop it will never be economical anyway.

There are lots and lots of people who would be happy to get a couple million
for some fusion projects. Others believe they could build a break even project
with 10s millions. And we could reinforce projects that make rapid
advancement.

It would also create a large fusion industry with different companies going
into 'supplier' mode and so on.

~~~
sgift
> And I would even be happy with just 3-5 projects that get many, many
> billions in the end. I mean lets be honest, if it costs $20 billion (and
> lets be honest it will be way more) to develop it will never be economical
> anyway.

It's a science project. It doesn't have to be economical. It is there to
establish the path to
[https://en.wikipedia.org/wiki/DEMOnstration_Power_Station](https://en.wikipedia.org/wiki/DEMOnstration_Power_Station)

> There are lots and lots of people who would be happy to get a couple million
> for some fusion projects. Others believe they could build a break even
> project with 10s millions. And we could reinforce projects that make rapid
> advancement.

Many people believe many things. There's a reason we do ITER: It has the best
chance to actually work, unlike all the "cheap" 'hey, I'm a genius, I can do
it with far less money!' projects out there.

~~~
nickik
> It's a science project. It doesn't have to be economical. It is there to
> establish the path to
> [https://en.wikipedia.org/wiki/DEMOnstration_Power_Station](https://en.wikipedia.org/wiki/DEMOnstration_Power_Station)

Its a wildly expensive science project that produces far less science and far
more overhead and waste.

And as we have already established, for such a long project it gets overtaken
by technology.

And the 'powerstation' will cost billions upon billions more and it will still
not even be close to economical.

> Many people believe many things. There's a reason we do ITER: It has the
> best chance to actually work, unlike all the "cheap" 'hey, I'm a genius, I
> can do it with far less money!' projects out there.

By what definition of 'work'? They might manage to get break even if they
throw enough money at it. But if you had said, any project that shows break
even can get 1 billion. That would be an effective use of money.

An I'm not saying any of these projects should get 20 billion because they
think they are smarter. But how about getting 2 million and if you show
impressive results you get 20 million and then maybe 200 million.

