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ITER: World's largest nuclear fusion project begins assembly

bbc.co.uk

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Re: ITER: World's largest nuclear fusion project begins assembly

#131

Post by ptmcc »

andrepd wrote: post #39
usui wrote: post #7

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…

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 a…

When accounting for all externalities, hydro doesn't usually pencil out all that well. It's a sad reality, because through a certain limited lens hydro looks amazing.

There are many efforts underway removing old hydro dams to restore the environments and ecosystems that were totally devastated by them.

A notable recent example is the Elwha River Dam removal that finished about 4 years ago in Washington: https://therevelator.org/elwha-dam-removal/

Re: ITER: World's largest nuclear fusion project begins assembly

#132

Post by Reason077 »

throwaway0a5e wrote: post #113
ClumsyPilot wrote: post #86

Earlier quoted context omitted.

What part of a wind turbine 'greatly poisons iur planet"? Its an electric generator on a mast. How is it more poisonos than any other industrial object or consumer device?

>What part of a wind turbine 'greatly poisons iur planet"? The batteries they're going to be paired with unless some other storage tech becomes better or windmills become so cheap that we can use less storage or inefficient storage. The windmills themselves are mostly fine since they're just fiberglass, metals and concrete. Mining for the things that go into batteries is just as destructive as the mining done for coa…

> "Mining for the things that go into batteries is just as destructive as the mining done for coal."

Most of what goes in to batteries can be recycled. You can't recycle coal.

Re: ITER: World's largest nuclear fusion project begins assembly

#133

Post by Avicebron »

StanislavPetrov wrote: post #120
andrepd wrote: post #39

Earlier quoted context omitted.

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 a…

>>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 also not true if we dealt with the massive overpopulation of the earth instead of acting as its some sort of moral crisis not to stuff as many people as possible onto a planet with finite renewable resources.

How do we go about dealing with the massive overpopulation?

Re: ITER: World's largest nuclear fusion project begins assembly

#134

Post by godelski »

petschge wrote: post #13
usui wrote: post #7

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…

The simple answer is that the surface only goes up a factor of 4 if you increase the radius by a factor of 2, but the volume goes up by a factor of 8. So the ratio of (energy containing) volume to surface (where energy get's lost) if getting better with increasing size. There is of course much more complicated answers, all the way up to full-device simulations using gyrokinetic codes like Gene or Gkeyll that take mil…

This is the main issue and I don't want to make it any more complicated. But I do want to explain something because people hear arguments between fusion scientists. Within the field no one really doubts that ITER is going to work (there's a few, of course, but the majority don't doubt). The thing they are arguing over is if it is needed. The big reason for ITER is not to generate power but to demonstrate that sustainable fusion is achievable. The idea is that if there is a demonstration people will stop shying away from it and investing would skyrocket (a government would have to be dumb not to substantially invest in PROVEN fusion devices). The counter argument is that there is enough funding and that they will beat ITER to the punch with small scale reactors (much closer to the path for devices that would provide actual energy to our grid). My take is "don't put all your eggs in one basket."

Re: ITER: World's largest nuclear fusion project begins assembly

#135

Post by beachy »

usui wrote: post #7

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…

If as you say...

"nuclear power is the only realistic way to solve the looming energy crisis of the 21st century"

because...

"most people around the world think that nuclear fission is scary"

then we are fucked as a species.

Science does not respect people's feelings. If people have scary feelings about energy/climate change/wearing masks to prevent a disease that travels in the air, then those feelings need to be changed, or those people need to be sidelined.

What we must not do - what we cannot afford to do - its to derail the science to assuage the deniers.

Re: ITER: World's largest nuclear fusion project begins assembly

#136

Post by OptionX »

petschge wrote: post #83
OptionX wrote: post #33

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

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…

Very well explained, thank you!

Re: ITER: World's largest nuclear fusion project begins assembly

#137

Post by twic »

DubiousPusher wrote: post #119
petschge wrote: post #48

Earlier quoted context omitted.

Yes that has a big impact. The quality of a tokamak (as meassured by the triple product density, temperature, and confinement time) goes up like B^3 (IF I remember correctly, I do plasma physics but not fusion stuff) and the fussion power goes up like B^4 or something like that. So larger magnetic fields help a lot. But back when ITER was designed we did not have such strong superconductors yet. PS: Google found DOI…

Is there a successor to iter already being worked out on paper that takes into account new developments?

Yes - the sequence is ITER, DEMO, then PROTO:

https://en.wikipedia.org/wiki/DEMOnstration_Power_Station

https://en.wikipedia.org/wiki/PROTO_(fusion_reactor)

Re: ITER: World's largest nuclear fusion project begins assembly

#138

Post by godelski »

andrepd wrote: post #39
usui wrote: post #7

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…

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 a…

The question about needing nuclear really comes down to how you model energy dependence. Is the US (or X country) homogeneous in ability to produce, store, and distribute energy or is it heterogeneous?

Of course, things get much more complicated once we start talking about lifetime emissions and external environmental impacts.

Re: ITER: World's largest nuclear fusion project begins assembly

#139

Post by Ygg2 »

cwhiz wrote: post #128
dantillberg wrote: post #100

Earlier quoted context omitted.

You could imagine building a globe-spanning power distribution network. Solar panels on one side of the planet could provide power at night on the other side of the planet.

If we could transmit power across vast distances like that then we wouldn't even need to bother with solar. We could build a thousand nuclear power plants in the middle of nowhere. Unfortunately, power transmission suffers from line losses. Even a few hundred miles requires several hundred thousand volts to avoid losses. Maybe that's an easier problem to solve than fusion.

You'd JUST need to move current from AC to DC, and span the whole of earth with superconductor cables.

You know, easy stuff to build and maintain.

Re: ITER: World's largest nuclear fusion project begins assembly

#140

Post by wcarss »

DubiousPusher wrote: post #119
petschge wrote: post #48

Earlier quoted context omitted.

Yes that has a big impact. The quality of a tokamak (as meassured by the triple product density, temperature, and confinement time) goes up like B^3 (IF I remember correctly, I do plasma physics but not fusion stuff) and the fussion power goes up like B^4 or something like that. So larger magnetic fields help a lot. But back when ITER was designed we did not have such strong superconductors yet. PS: Google found DOI…

Is there a successor to iter already being worked out on paper that takes into account new developments?

Yes, the video above is basically about this, and is really worth watching -- it's a fantastic talk.

I'm pretty sure that Commonwealth Fusion Systems[0] is the entity affiliated with MIT that has been doing work to prove out the recently available higher magnetic field strength superconducting materials and apply them to tokamak construction to bring size down dramatically. They had a bunch of press in 2018/2019 when they first got underway[1], and it looks like they've received a lot more investment over the last few years and likely made quite some progress since then[2].

0 - https://cfs.energy/ 1 - https://www.bostonglobe.com/opinion/2018/03/09/new-approach-... (op-ed in the Boston Globe by a Vice President at MIT) 2 - https://cfs.energy/press/

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