
World's Largest Nuclear Fusion Experiment Clears Milestone - tshannon
https://www.scientificamerican.com/article/worlds-largest-nuclear-fusion-experiment-clears-milestone/
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b_tterc_p
Let’s say ITER works exactly as planned at some point in the future (delayed
or not). How far are we from commercial fusion power as a reasonable source
for things?

~~~
vkou
Far enough away that even if there are no issues with scaling, we're going to
face a climate change catastrophe, before we can replace fossil fuels with
fusion.

We need to take drastic action on power generation in the next _decade_. There
isn't a snowball's chance in hell that fusion will make it in time. I can't
over-emphasize how dire our current situation is - and that's with us
currently living in a world where 3 cent/kwh solar power exists.

If we're gambling on fusion, at this point, the best-case outcome for it would
be that it could be brought online sometime between us hitting 'drastic
climate catastrophe' and 'civilization ending climate catastrophe'. To me,
that doesn't sound like a great situation to be in.

~~~
Retric
Fusion is not about climate change.

It’s one of those things that enable sending spacecraft to other stars. D-T
fusion is still baby steps on that path, but worthwhile none the less.

~~~
pfdietz
DT fusion would be terrible for spacecraft, since 80% of the energy comes out
as neutrons, and those neutrons need to be captured and thermalized in a
blanket to make more tritium. A fission rocket would have better performance.

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united893
Can someone help me understand the engineering and economics of distributing
energy from a fusion plan?

Let's assume that in 2035 ITER reaches its goal and can sustain fusion at a
cost of ~$25B per plant w/ $1B in yearly operational costs. Now what? Do we
then build a nuclear-plant-style pressurized water turbine? How many turbines
can we place around a fusion plant? How far can we distribute this power?

According to this[1] paper, fusion power becomes profitable at $175/Mwh.
Nearly every other type of energy source, including wind and PV is cheaper[2]

[1] [https://sci-
hub.tw/https://www.sciencedirect.com/science/art...](https://sci-
hub.tw/https://www.sciencedirect.com/science/article/pii/S0360544218305395)

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

~~~
zaarn
Fusion has advantages over Wind and PV; it works like a nuclear power plant.
That means you can build a large plant where the power is needed and then
provide it continously without stopping. Wind and PV can't do that unless you
add buffer technology, but even that has limits.

Fusion can easily provide 100% of our baseline power needs and because it's
powered by the most common elements in the solar system, it can easily be
harvested (even from solar wind, which should deliver more than enough to
power humanity with fairly little effort). Fusion is essentially the key to
unlocking unlimited power (insert emperor palpatine here).

With only 100'000 tonnes of water, filtered for deuterium, the US could cover
it's annual electricity needs entirely. The Mississipi provides this much
water over 6 seconds.

60 seconds are enough to cover the entire world's annual energy needs.

~~~
pfdietz
Fusion has the disadvantages of nuclear. It will be very expensive. Nuclear is
not competitive even if the nuclear island is FREE; the non-nuclear thermal
power plant part is too expensive. Since fusion reactors themselves are
unlikely to cost negative dollars, fusion power plants won't be competitive
either.

~~~
zaarn
I don't think that is true for baseline power provision, only for the peak
demands during the day alternatives are viable.

For baseline, Fusion doesn't compete with PV and Wind, it competes with
Batteries powered by PV and Wind, which is a whole different price
calculation.

That plus the fuel is common and cheap to obtain, unlike Uranium or some of
the rare earth metals for PV.

~~~
pfdietz
On a levelized basis, nuclear is grossly uncompetitive.

This means that when the wind is blowing, or the sun is shining, nuclear
cannot sell for close to what it needs to make ends meet.

Cheap batteries are just going to be the final nail in the coffin. At the
current rate of decline of battery prices I expect most operating nuclear
reactors to shut down within a decade.

Oh, and please don't repeat the "PV needs rare earth metals" lie. They don't
use rare earths, or for that matter need any rare elements at all. The only
somewhat rare element silicon PV uses is silver for front contact wires, but
that can be substituted for with copper (with a migration barrier layer to
prevent reaction with silicon) if silver gets too expensive.

~~~
zaarn
I don't think your expectations are realistic and underestimate the cost of
baseline power. Baseline means this is how much the grid is pulling 24/7
without any pause.

You'd cycle batteries fairly fast if that was the only option which would
increase the price, plus you'd now operate two powerplants; PV and battery.

Fusion and other thermal plants are more suited to providing baseline load. A
fusion reactor that is running at a predictable minimum of 30% would cost far
less than any PV/Wind/Battery system every could.

~~~
pfdietz
I think you're committing the common error of thinking that baseload demand
requires baseload supply.

But baseload supply was just the most economical way to supply baseload
demand. I emphasize _was_. We are moving into a new situation where
intermittent sources are much cheaper than those old reliable baseload
sources, when they are available. If this cost discrepancy becomes too large,
the optimum mix of sources will change abruptly, to some combination of
intermittent sources and various forms of storage.

The levelized cost advantage of renewables has become very large. Right now,
they pair with dispatchable sources (gas, primary hydro), but storage is
beginning to undercut that. Baseload nuclear is already grossly uncompetitive;
in the US to compete with the current gas/renewable mix new nuclear would
require a CO2 tax of $300/ton or higher. Even existing nuclear is struggling
to meet its operating costs here.

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ttul
While there are many hopeful alternatives to “big fusion” which may promise to
be cheaper, is it not true that ITER is the most credible path to commercial-
scale fusion power?

~~~
ChuckMcM
I've been watching the progress of the Wendelstein 7-X
([https://www.ipp.mpg.de/4550215/11_18](https://www.ipp.mpg.de/4550215/11_18))
which has been making steady progress month after month, year after year. At
the current pace they will demonstrate net power fusion before ITER does.
Extrapolation is always risky though so it isn't something one should count
on.

~~~
Tossrock
The Wendelstein 7-x is not designed to ever reach ignition. It's a (very
large, very cool) research reactor studying stellarator geometry. Ignition
will require a yet larger device, and barring any disasters, ITER should
definitely get there first.

~~~
ChuckMcM
I understand that, these are the bits that I like about the project:

 _" Then, it will remain to be seen whether Wendelstein 7-X can also fulfil
its optimisation goals during continuous operation – the essential advantage
of stellarators."_ ... _" Although Wendelstein 7-X is not designed to generate
energy, the device is intended to prove that stellarators are suitable for use
in power stations."_

And from the ITER Goals statement
([https://www.iter.org/sci/Goals](https://www.iter.org/sci/Goals)) _" ITER
will not capture the power it produces as electricity, but as the first of all
fusion experiments in history to produce net energy... it will prepare the way
for the machine that can."_

My take away from that, is that if both machines fulfill their goals, then
building a power station that uses the technology would be the next step. I
expect two things to be true; First, the 7-x will prove out its goals before
ITER does, and second given that the stellerator design is significantly less
complex than the tokamak design, it will be realized as a test power plant
before the tokamak power plant is.

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erobbins
Fusion as a power source is only 30 years away now :)

~~~
Iv
Actually with the level of funding it got, that was predicted:
[https://qph.fs.quoracdn.net/main-
qimg-762f32a6dbfbecc4ec824b...](https://qph.fs.quoracdn.net/main-
qimg-762f32a6dbfbecc4ec824b604c0571f0.webp)

What the hell happened to optimism and trust in science? We used to be able to
say "In 10 years there'll be a man on the moon" without having ever launched
anyone in space. Now people doubt that in 50 years we will have a marginally
better battery technology...

Fusion would be there already if only we had believed in it.

~~~
rgbrenner
This chart always gets trotted out whenever this comes up.

You cannot know what it will cost to invent something before it is invented.
You cannot know how many deadends you will have to go down before you find one
that works. In fact, it may be that the invention depends on knowledge or
technology that we don't have, and maybe won't have for many many years.

For example, today fusion researchers are using computers to simulate plasma
flows, gain a better understanding of plasma, and design better reactors...
something that was not possible in the mid-70s when that chart was created..
and would not be possible to do by hand (as was done in the 70s). Hundreds of
billions of dollars have gone into creating computers capable of doing that...
where is that in your chart?

And to preempt this line: saying they could buy a supercomputer is not a
rebuttal. A Cray-2 was the 2nd fastest computer in the world from 1985-1990
(10-15 years after your chart). It's the equivalent to an ipad 2 (a 2011
32-bit mobile low-power processor). I'm using a computer many times faster
than that just to type this post.

~~~
credit_guy
In addition to what you said, I think our perception of the Manhattan and
Apollo projects is skewed by survivorship bias [1]. These projects kept
hitting milestones, so they kept getting additional funding, until their
successful final delivery. It's quite likely that many, many more projects
(laser weapons, scramjets, ekranoplanes) experienced a funding flatline like
the fusion famous graph, simply because their milestones proved elusive. It's
better to deliver results than excuses and delays.

[1] [https://xkcd.com/1827/](https://xkcd.com/1827/)

~~~
adrianN
The most important fusion power metric has actually improved really fast,
despite the abysmal funding situation:
[https://imgur.com/BN0pz](https://imgur.com/BN0pz)

~~~
credit_guy
Very interesting graph, thanks for sharing. I guess the point of the graph is
that the progress in fusion has been steady and followed an exponential low
for 3 decades, in a way that matches the Moore law.

If I were a politician in 2019 with the right to sign funding and I see this
graph, I cut all funding right away. Here's why:

* based on this graph, a simple extrapolation by only 2 years show the achievement of the commercial reactor in 2005. Where's the commercial reactor 14 years later? We are instead only 6.5 years away before pushing a certain button at ITER, which has some type of significance that's not entirely clear

* at least one point on this graph is "cooked": the JT-60U that appears to cross the breakeven point at some point prior to 2000. Here's what wikipedia [1] says about this:

"During deuterium (D–D fuel) plasma experiments in 1998, plasma conditions
were achieved which _would have achieved break-even—the point_ where the power
produced by the fusion reactions equals the power supplied to operate the
machine—if the D–D fuel were replaced with a 1:1 mix of deuterium and tritium
(D–T fuel)."

What's the point of the "figure-of-merit" graph then? It projects when we'll
get to breakeven or commercial, only to find there that you need to make
another tiny change (i.e. substitute D with T) that will take 30 more years?

[1]
[https://en.wikipedia.org/wiki/JT-60#JT-60U_(Upgrade)](https://en.wikipedia.org/wiki/JT-60#JT-60U_\(Upgrade\))

~~~
petschge
ITER is far behind that growth curve because its cost is beyond what a
university or national research lab is filling to fund. To unlike a lot of
other projects before it, it is this massively political beast. Involving
politician by itself introduces at least a decade of delay.

The triple product is the correct figure of merit and JT-60U did great there.
But it was a plasma experiment and did not have the shielding that is
necessary to run it with D-T fuel that produces a lot of neutron during
fusion. But we know a lot more about neutron fielding than we know about
magnetically confined fusion. Improving the plasma handling and the triple
product is much harder than adding shielding.

~~~
credit_guy
> The triple product is the correct figure of merit and JT-60U did great
> there.

Look. If you have a graph where you show a certain point called "figure-of-
merit" being above a so called break-even point, every layperson in this world
will assume that you get more energy out than you put in. If you then say that
it's breakeven for a different reaction, they'll either question your sanity,
or they'll accuse you of bait-and-switch. If you don't understand why you get
your funding cut, you'll think life is unjust or cruel. Other people will nod
sympathetically when you'll complain of the unfairness of this world , but
secretly they'll disagree with you.

~~~
petschge
Well, lay people have no clue. And probably should not be in charge of
funding.

~~~
credit_guy
The money comes from them, you know? One way or another, they are in charge of
funding, and the way to help them make better decision is to be truthful, not
to massage the message (you want to tell me it's really ok to compare a figure
of merit for a reaction with the breakeven point for another reaction? * )

So, here's what Zubrin has to say about nuclear fusion and ITER [1]: "While,
driven by international rivalry, the world's national fusion programs did
advance forcefully between 1960 and 1990, the decision to consolidate all of
them into a unified global effort to build the International Experiment
Reactor (ITER) has caused nearly all progress to screech to a halt since the
1990s."

Why did this happen? Could it be because laypeople in charge of funding
listened to scientists lobbying for a cool (and expensive) magaproject?

[1] [https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-
redirect?...](https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-
redirect?_encoding=UTF8&btkr=1)

( * ) in all fairness, you only argued that the figure-of-merit it a good
metric, which I don't contest.

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frankbreetz
Does anyone know the risk of meltdowns for fusion? I know the energy released
is several orders of magnitude larger then that of fission(what nuclear power
plants do now), so I would assume a meltdown would be several orders of
magnitude worse. If we can create energy through fusion safely it really is
unlimited carbon neutral energy. There is a limit, but the natural end of the
planet will happen first. This is great news! I had no idea we were this close
to fusion.

~~~
Ididntdothis
As far as I know there is no risk for a meltdown. The amount of energy/fuel in
the reactor at any given moment is pretty low. Unlike with a fission reactor
they have to keep feeding the reactor constantly or it will stop.

~~~
TallGuyShort
I could imagine that the fuel supply getting jammed on is not so dissimilar
from the control rods being jammed out.

~~~
altec3
Armchair opinion: I believe the fuel isn't radioactive, and neither is the
reaction. So while it could blow up, it's not going to have a ton of
radioactive fallout.

Sort of like a fusion bomb, the fusion bomb doesn't produce radioactive
fallout, but the fission bomb necessary to start the fusion bomb does.

~~~
sbierwagen
D-T fusion, which ITER will use, produces neutron radiation, which will cause
neutron activation in reactor components, rendering them radioactive:
[https://en.wikipedia.org/wiki/Neutron_activation](https://en.wikipedia.org/wiki/Neutron_activation)

Aneutronic fusion is possible, but requires collision energies much higher
than what ITER is designed to create.

~~~
Symmetry
In theory you can chose construction materials that don't do anything too
horrible when you bang them with neutrons in the construction of your fusion
reactor. I'm not sure how well this is achievable in practice in the
construction of a fusion reactor but I'm pretty sure they can avoid using
anything that creates byproducts as nasty as uranium does.

EDIT: I do wonder if there's a danger of nuclear proliferation with using
fusion reactors to breed plutonium from natural uranium, though.

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s9w
I don't think ITER stands for "International Thermonuclear Experimental
Reactor" anymore.

~~~
s9w
To the people that downvote me: it used to stand for that, but not anymore.

