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Major breakthrough on nuclear fusion energy

bbc.co.uk

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Re: Major breakthrough on nuclear fusion energy

#701

Post by credit_guy »

brutusborn wrote: post #695
credit_guy wrote: post #683

Earlier quoted context omitted.

Who is "we"? Fracking was funded with private money. It was "conventional" technology, no edge-of-science stuff, so private entrepreneurs could afford it, and the rewards were quick to materialize. Nuclear fusion? There's this urban myth that fusion could have been achieved if only we'd have poured more money into it, but where's the evidence? Plasma modeling requires a lot of computational power. What you have now i…

I think you're mistaken about the government involvement in fracking. Sure, the basic technique may have been developed by private companies, but government supported research expanded it to oil and gas applications. https://thebreakthrough.org/issues/energy/us-government-role...

> government supported research expanded it to oil and gas applications.

The Government gets involved in a lot of things, but it doesn't mean its contribution is essential. For a recent example, the NIH is claiming the Moderna vaccine is due to their contribution, and sure, you'll be able to find one or a few grants here or there of a few hundred thousand dollars, but the massive investments of tens of millions of dollars were done by Moderna itself.

As for fracking, the father of fracking is considered to be George P. Mitchell [1].

[1] https://en.wikipedia.org/wiki/George_P._Mitchell

Re: Major breakthrough on nuclear fusion energy

#704

Post by gtirloni »

kolinko wrote: post #631
gtirloni wrote: post #113

Earlier quoted context omitted.

Solar panel manufacturing and disposal is far from clean though.

What disposal? Less than 1% of the solar plants have been ever decommissioned. It's hard to set up recycling plants if you have nothing to recycle yet.

Lifespan is 25-30 years, they don't last infinitely. What's your point?

Re: Major breakthrough on nuclear fusion energy

#705

Post by thedougd »

xxs wrote: post #636
thedougd wrote: post #628

Earlier quoted context omitted.

EU is on 50hz AC, where as the US is on 60hz. It would work fine for purely resistive appliances, and possibly devices with switching mode power supplies, but some devices would be unhappy plugging in to the wrong frequency at 220V. I'm not sure about the phase alignment but that may be an issue as well. US is split phase, but Europe has 220 on a single conductor?

it's 230 (+-10%) nominal not 220. At my house it's around 235. It's 230v phase/live to neutral and 400V between live wires in 3phase. Nowadays 3-phase (120degree between each) is a commodity.

Thanks for that. Sounds wonderful compared to the typical 200 amp, split phase service we commonly have in the US.

Re: Major breakthrough on nuclear fusion energy

#706

Post by kadoban »

avidphantasm wrote: post #682
ppaattrriicckk wrote: post #59

In extension to this news and the press conference, one thing I am super excited about, is the private SPARC project and the MIT-spinoff Commonwealth Fusion Systems (CFS). If you don't know about it already, I would highly recommend checking it out (e.g. by searching YouTube for "MIT Sparc Fusion Reactor" for some fairly accessible videos on the theory behind why they should achieve fusion way faster than the current…

At this point, I think fusion has the best chance of saving us from ourselves wrt to climate change, so long as the unforeseen consequences aren’t too bad.

It doesn't seem like it's quick enough. We're, at minimum, decades away from it even being built out commonly, and to _really_ save ourselves we should have already replaced a substantial portion of the world's energy generation decades ago.

Re: Major breakthrough on nuclear fusion energy

#707

Post by drjesusphd »

dkbrk wrote: post #687
ppaattrriicckk wrote: post #59

In extension to this news and the press conference, one thing I am super excited about, is the private SPARC project and the MIT-spinoff Commonwealth Fusion Systems (CFS). If you don't know about it already, I would highly recommend checking it out (e.g. by searching YouTube for "MIT Sparc Fusion Reactor" for some fairly accessible videos on the theory behind why they should achieve fusion way faster than the current…

> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop Here's the quick summary: B: magnetic field strength R: length scale Fusion rate ∝ (plasma pressure)^2 ∝ B^4 Energy gain (Q) ∝ R^1.3 B^3 Power density ∝ R B^4 Cost ∝ R^3 So, say for example you're targeting a fixed Q. Doubling the magnetic field strength result…

To be fair, the main reason instabilities are less of a concern is wrapped up in that B^4 scaling.

Re: Major breakthrough on nuclear fusion energy

#708

Post by ketozhang »

ketozhang wrote: post #642
advisedwang wrote: post #348

Earlier quoted context omitted.

Water has a specific heat capacity of 4184J/kg/C. Lets say to get to the boil you need to go from 20C to 100C and that a kettle holds 1.75L. 59MJ / (80C * 4184J/kg/C) = 176kg ~= 176L ~= 100 kettles. Water has a latent heat of vaporization of 2260 kJ/kg. So to boil it dry: 59MJ / (80C * 4184J/kg/C + 2260 kJ/kg) = 22kg ~= 22L ~= 12 kettles. I have no idea what the journalist calculated.

I think the journalist is calculating load capacity. A 1500A @120V kettle requires 0.18 MW. Rounding up, 60 kettles requires 12 MW. It's not how much water you can boil, it's how many kettles you can run at the same time.

I'm way off. I meant 15A. Now I've no clue what the journalist is calculating.

Re: Major breakthrough on nuclear fusion energy

#709

Post by iaw »

fouc wrote: post #698
iaw wrote: post #632

I am a strong proponent of Fusion energy and did some work on the subject in undergrad. This is not a major breakthrough, it's a benchmark. A major breakthrough would be materials that could withstand the neutron bombardment longer, the ultimate limiting factor for fusion energy plants after we achieve positive net energy.

What I'd like to know is what design or material changes were required to reach this benchmark? The picture of the fusion chamber is still the same torus donut shape as the ones from the 90s.

I believe the issue is that the surrounding materials of the torus in the TOKAMAK become highly radioactive due to neutron bombardment and decay accordingly.

IIRC, there is some sort of Silicon Carbon based material that need to be economically feasible to manufacture (that can withstand a fair amount of neutron bombardment without crumbling like other materials) before a plant will ever make sense. There may be alternative materials but none of them are cheap enough to build a long-term TOKAMAK even if we could achieve the incremental net power necessary for a power plant.

Re: Major breakthrough on nuclear fusion energy

#710

Post by dkbrk »

drjesusphd wrote: post #707
dkbrk wrote: post #687

Earlier quoted context omitted.

> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop Here's the quick summary: B: magnetic field strength R: length scale Fusion rate ∝ (plasma pressure)^2 ∝ B^4 Energy gain (Q) ∝ R^1.3 B^3 Power density ∝ R B^4 Cost ∝ R^3 So, say for example you're targeting a fixed Q. Doubling the magnetic field strength result…

To be fair, the main reason instabilities are less of a concern is wrapped up in that B^4 scaling.

I understand there's a bit more to it than that.

Here's the section in Professor Whyte's talk: https://youtu.be/KkpqA8yG9T4?t=2215

> It's even more subtle than that, in fact this is really one of the things we've studies at MIT, is that there's other things that come in terms of benefits, particularly when you make the magnetic field very high, it basically starts to tame, just all of the whole suite of plasma instabilities that exist.

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