Merged How Close is power from Nuclear Fusion

Puppycow said:
This is the ultimate problem. Even if we assume that they finally figure this out and are able to make a piece of equipment that can stably sustain a fusion reaction and figure out a mechanism that can turn the surplus energy produced by the reaction into electricity, what if it's just plain too expensive in the end?
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Then we should still do it, just on a much more limited scale, and probably just for research purposes.
 
If it's sustainable, it's not explosive. At least not in the sense that I normally understand "explosive". Are you thinking, what if the reaction releases more energy than can be contained by the reaction vessel? Because that seems like a relatively minor engineering problem, if you're able to run a sustained fusion reaction that is (a) net surplus and (b) produces a harnessable surplus.

We've run into this problem before, with internal combustion engines (which really are explosive). A major obstacle to heavier-than-air flight was coming up with materials that were strong enough to contain the explosions of the ICE, but light enough to be carried into the air by the power they were producing. And we've run into this problem, too with fission reactors. It's just a matter of building a heavier, stronger containment vessel.

My expectation is that if we do ever figure out sustainable, harnessable fusion power, we will inevitably figure out a suitable containment vessel.
 
Roboramma said:
Am I missing something? I don't think anyone said anything about fusion reactors being explosive.
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Ah. Yeah, my bad. Puppycow wrote too expensive, I read too explosive.

Anyway, I'm not sure "too expensive" is a real problem. If it's sustainable and produces a net surplus of energy, it's a practically unlimited source of power. The fuel for it is water - abundant and cheap. How could that be "too expensive".
 
Setup costs. The fact that it will pay for itself over time doesn't mean that you don't have to find the setup funding now.
 
theprestige said:
Ah. Yeah, my bad. Puppycow wrote too expensive, I read too explosive.
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, Ah, thanks, that makes sense.

Anyway, I'm not sure "too expensive" is a real problem. If it's sustainable and produces a net surplus of energy, it's a practically unlimited source of power. The fuel for it is water - abundant and cheap. How could that be "too expensive".
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arthwollipot said:
Setup costs. The fact that it will pay for itself over time doesn't mean that you don't have to find the setup funding now.
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This, but also the fact that it produces net power, even with near zero fuel costs, doesn't mean it will pay for itself over time. Even ignoring maintenance costs, which could be very large, and other running costs (even if fuel is cheap you may need many highly skilled workers), the cost of capital isn't zero. If it costs a billion dollars to build, you either need to get a billion dollar loan, and thus have interest payments, or you've got a billion dollars and you put that into building your fission plant instead of investing it in something else. The opportunity cost is basically the same as the interest on a loan. To be profitable, to "pay for itself over time", that plant needs to produce an income greater than those interest payments. Depending on the upfront cost of building the plant, and the amount of net power it produces, that may or may not be possible.

Ie. If you borrow a billion dollars to produce a fission plant that completely runs itself and has not operating costs, but produces only 1 kilowatt of net power, you'll end up going deeper and deeper into debt. And if you financed it yourself you'll end up with less income than you could have had by investing that money elsewhere.
 
theprestige said:
Ah. Yeah, my bad. Puppycow wrote too expensive, I read too explosive.

Anyway, I'm not sure "too expensive" is a real problem. If it's sustainable and produces a net surplus of energy, it's a practically unlimited source of power. The fuel for it is water - abundant and cheap. How could that be "too expensive".
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We would also need supply of material from CANDU reactors (tritium), or go to the far side of the moon for it, or find a way to run all future fusion reactors perfectly, which I highly doubt will happen.
 
There have been so many false alarms about a breakthru in Fusion that will beiieve it whent he first fusion power plant starts operating.
 
dudalb said:
There have been so many false alarms about a breakthru in Fusion that will beiieve it whent he first fusion power plant starts operating.
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Those haven't been false alarms. They have been genuine breakthroughs and extremely necessary if we're going to crack this nut.

We just need about ten thousand more of them. Turns out it's complicated and hard.
 
theprestige said:
Ah. Yeah, my bad. Puppycow wrote too expensive, I read too explosive.

Anyway, I'm not sure "too expensive" is a real problem. If it's sustainable and produces a net surplus of energy, it's a practically unlimited source of power. The fuel for it is water - abundant and cheap. How could that be "too expensive".
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Others have chimed in already with most of the points I would have made. I do wonder though if plain old water is actually sufficient as a fuel or if you need special isotopes of hydrogen such as deuterium and tritium. Those are far less common, and the process to sort them from the most common isotope, which accounts for 99.9855% of naturally occurring hydrogen, could be expensive in itself. If deuterium is sufficient, that seems to cost about $2,500 per kilogram (for heavy water). Tritium is even pricier, at about $30,000 per gram ($30 million per kilogram).

The ITER experimental reactor is set to cost about 20 billion euros and won't even produce electricity.

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

So yes, I think it's quite plausible that even if we figure out how to do it, it will still be much more expensive than other ways of generating commercial electricity. Regular water may not be all that is needed as fuel.
 
Inching closer?

Korea’s ‘artificial sun’ achieves a record 48 seconds at 100 million degrees. Why does it matter?

KSTAR serves as a pilot for the France-based International Thermonuclear Experimental Reactor (ITER) which Euronews Next visited last year. The “artificial sun” provides information that will help better understand fusion.
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and
“To achieve the ultimate goal of KSTAR operation, we plan to sequentially enhance the performance of heating and current drive devices and also secure the core technologies required for long-pulse high-performance plasma operations,” he added.
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Roger Ramjets said:
30 seconds in 2021, 48 seconds in 2024. 'Inching' is right. At this rate they'll have reached 2 minutes by 2032. Woohoo!
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I'd be happy with that, but they're actually shooting for 5 minutes by 2026. It seems reasonable to surmise that once they get the hang of sustaining the reaction, new records will start coming quicker and quicker.
 
If I understand these tokamak experiments correctly, they're about using brute magnetic force and computing power to control a chaotic mass of plasma. That is to say, less like the oft-invoked "magnetic bottle" metaphor of a magnetic field just quietly containing all the plasma, and more like a bunch of magnetic Pong paddles frantically maneuvering to shove wayward streams of plasma back into place.

If that's so, then once the design and coding of the system reaches a certain threshold of adequacy for that task, we might very well be seeing rapidly increasing containment times.

What comes after that? Do they need to further pinch (compress) bits of the plasma to make enough fusion happen? Or step up to even higher temperatures? Or use different H isotopes? Or is there enough fusion happening already, and the additional heating from that is one of the limits on containment time? (In which case, it appears there's no way yet to remove the generated heat from the chamber or make use of it.)
 
Myriad said:
If I understand these tokamak experiments correctly, they're about using brute magnetic force and computing power to control a chaotic mass of plasma. That is to say, less like the oft-invoked "magnetic bottle" metaphor of a magnetic field just quietly containing all the plasma, and more like a bunch of magnetic Pong paddles frantically maneuvering to shove wayward streams of plasma back into place.

If that's so, then once the design and coding of the system reaches a certain threshold of adequacy for that task, we might very well be seeing rapidly increasing containment times.

What comes after that? Do they need to further pinch (compress) bits of the plasma to make enough fusion happen? Or step up to even higher temperatures? Or use different H isotopes? Or is there enough fusion happening already, and the additional heating from that is one of the limits on containment time? (In which case, it appears there's no way yet to remove the generated heat from the chamber or make use of it.)
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The road to (useful) power from nuclear fusion is a two step process.

1. Create a sustainable reaction (one that doesn't just last for a few second and then requires a six day reboot) and
2. Find some way of transforming the power so generated into something useful (like electricity).

Neither one of these is apparently an easy problem to solve. :(
 
I the meantime - Cold Fusion is not dead yet!

Cold fusion is making a scientific comeback

A US agency is funding low-energy nuclear reactions to the tune of $10 million.

Earlier this year, ARPA-E, a US government agency dedicated to funding advanced energy research, announced a handful of grants for a field it calls “low-energy nuclear reactions,” or LENR. Most scientists likely didn’t take notice of the news. But, for a small group of them, the announcement marked vindication for their specialty: cold fusion.
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With all the money being spent on the hot kind, I guess a few bucks on something this cool are not inappropriate. ;)
 
ahhell said:
The navy could put them all on tread mills?


Or are you talking about the bombs and not the folks that run power plants?
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Project Orion is a nice way to get power out of nuclear weapons. Specifically to turn their explosive energy into propulsion and the kinetic energy of the spacecraft. I'm not sure you could actually use the existing arsenal for the purpose though, as they were meant to use a specific type of bomb that would explode in a sort of cigar shape rather than a spherical explosion. The original plan was also to use small fission bombs (like a few kilotons), rather the much larger fusion weapons, but there was a plan to scale the design to use fusion bombs as well.

As to power on earth, it's completely insane, but potentially if you go big enough you could use fusion bombs as the energy source for a power plant. You just have to go really big.
 
No, the present stock of nuclear weapons is not suitable for power generation. For a start, I believe that the type of plutonium in a fission bomb is quite different from nuclear fuel and can't be used in the same way.
 
arthwollipot said:
No, the present stock of nuclear weapons is not suitable for power generation. For a start, I believe that the type of plutonium in a fission bomb is quite different from nuclear fuel and can't be used in the same way.
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Weapons use plutonium + hydrogen, neither of which is used in nuclear power stations.
 
arthwollipot said:
No, the present stock of nuclear weapons is not suitable for power generation. For a start, I believe that the type of plutonium in a fission bomb is quite different from nuclear fuel and can't be used in the same way.
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I'm mostly joking, but I'm talking about the idea of actually exploding the bombs, say to heat a giant reservoir of water to power a giant steam engine. Yes, as I said its an insane idea.
 
Roboramma said:
I'm mostly joking, but I'm talking about the idea of actually exploding the bombs, say to heat a giant reservoir of water to power a giant steam engine. Yes, as I said its an insane idea.
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To get this to work you would need
1. A giant container with a mixture of gas and a liquid (maybe a salt or water?).
2. Something that will pump the liquid out to heat water, converting it to steam.
3. The steam will then generate electricity in the normal way.

The container would need to be several kilometers or more (depending on the size of the bomb) in diameter. This size will be needed to contain the explosion. The gas would help absorb the pressure of the explosion.

I would suggest that once everything had cooled down what would be left would be a lot of radioactive materials.
 
SURPRISE!

We’ll Have to Wait a Bit Longer for the World’s Biggest Fusion Reactor

By "Bit Longer" they mean "at least another generation."

Earlier this morning, the International Thermonuclear Experimental Reactor (ITER) Organization announced what has long been known: The largest tokamak in the world will be delayed further, prolonging the awaited nuclear fusion machine’s operations by at least a decade.
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The project’s previous baseline—its timeframe and the benchmarks within it—was established in 2016. The global pandemic that started in 2020 interrupted much of ITER’s ongoing operations, delaying matters further.

As reported by Scientific American, ITER’s cost is four times initial estimates, with the most recent numbers putting the project at over $22 billion. Speaking at a press conference earlier today, Pietro Barabaschi, ITER’s director general, explained the cause of the delays and the updated project baseline for the experiment.

“Since October 2020, it has been made clear, publicly and to our stakeholders, that First Plasma in 2025 was no longer achievable,” Barabaschi said. “The new baseline has been redesigned to prioritize the Start of Research Operations.”

Barabaschi said that the new baseline will mitigate operational risks and prepare the device for operations using deuterium-tritium, one type of fusion reaction. Instead of a first plasma in 2025 as a “brief, low-energy machine test,” he said, more time will be dedicated to commissioning the experiment and it will be given more external heating capacity. Full magnetic energy is pushed back three years, from 2033 to 2036. Deuterium-deuterium fusion operations will remain on schedule for roughly 2035, while the start of deuterium-tritium operations will be delayed four years, from 2035 to 2039.
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But the good news is that when we get to 2039, we'll still only be 20-50 years away from commercial production! That should be just in time to help the survivors of global warming who are huddled at the poles or in deep repurposed mines!
 
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As a young man i was fairly sure we would have commercial fusion power in my lifetime. Now I am quite sure we will not.
 
Puppycow said:
Also answers the question I had in #331: Yes, it will almost certainly require deuterium and tritium to run, not just just plain old protons (regular hydrogen), which means it ain't gonna be cheap.
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At least it will not require Unobtainium. The ship to Pandora has not been built yet. :(
 
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