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MIT-designed project achieves major advance toward fusion energy

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Re: MIT-designed project achieves major advance toward fusion energy

#91

Post by sdenton4 »

cletus wrote: post #87

I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what? Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40…

If only there were some way to capture and use all that power from the giant fusion reactor in the sky...

Re: MIT-designed project achieves major advance toward fusion energy

#92

Post by mLuby »

cletus wrote: post #87

I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what? Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40…

It seems you're suffering from "neutron embitterment." ;P

Space-based solar power generation (itself "fusion power" in the loosest sense) would be great in the inner planets.

Though to open up the outer planets, Kuiper belt, Oort Cloud, and any other stars, we'll need non-solar* power: hopefully fusion, at least fission.

*Unless we want to go the stellaser route, but I'd bet we'll crack fusion before getting near K2.

Re: MIT-designed project achieves major advance toward fusion energy

#94

Post by worldvoyageur »

anonuser123456 wrote: post #17
shmageggy wrote: post #7

These university press releases are always very positively framed. This one makes the new magnet seem incredibly promising and fusion seem like almost an inevitability now, but decades of failure have us conditioned for skepticism. What's the catch this time?

> What's the catch this time? This is D-T fusion. Which means you have to have T. Which currently comes from fission reactor and has a half life of 15 years. So the plan is to use a molten salt blanket with Be to breed T. But Be isn’t scalable for consumption, so maybe lead eventually. That’s probably do-able, it just slows down the rate new reactors can come online since Pb is not as good a neutron multiplier. Once…

Tritium is a natural byproduct of CANDU fusion reactors, of which there are some 25 or so in operation globally, mostly in Canada. CANDUs use heavy water as a neutron moderator (D20 instead of H2O), making T2O a natural byproduct.

Though most of the reactors do not harvest the tritium, a small number do.

CANDU operators have long been ready to make the capital investments in tritium harvesting, once demand materializes. ITER has long been seen as a potential major source of tritium demand.

Re: MIT-designed project achieves major advance toward fusion energy

#95

Post by mcswell »

anonuser123456 wrote: post #17
shmageggy wrote: post #7

These university press releases are always very positively framed. This one makes the new magnet seem incredibly promising and fusion seem like almost an inevitability now, but decades of failure have us conditioned for skepticism. What's the catch this time?

> What's the catch this time? This is D-T fusion. Which means you have to have T. Which currently comes from fission reactor and has a half life of 15 years. So the plan is to use a molten salt blanket with Be to breed T. But Be isn’t scalable for consumption, so maybe lead eventually. That’s probably do-able, it just slows down the rate new reactors can come online since Pb is not as good a neutron multiplier. Once…

"Hydrogen is very corrosive and hard to work with" Corrosive compared to what? You can put it in a rubber balloon and hand it to a kid.

"T is radioactive hydrogen": True, it emits low energy beta radiation, which is an electron, and is stopped by a sheet of paper. I used to have a wrist watch with a tritium dial; I haven't died of cancer yet.

Re: MIT-designed project achieves major advance toward fusion energy

#96

Post by pfdietz »

UnFleshedOne wrote: post #80
phscguy wrote: post #32

Earlier quoted context omitted.

Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress. I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessim…

There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing. Environmentally clean energy source is not enough, it needs to be ideologically pure as well.

This is projection. The irrationality is thinking that fusion is something desirable. I suspect this follows from exposure to fusion reactors as a trope in SF stories. From a hard nosed engineering point of view fusion is just terrible.

Re: MIT-designed project achieves major advance toward fusion energy

#97

Post by mcswell »

UnFleshedOne wrote: post #80
phscguy wrote: post #32

Earlier quoted context omitted.

Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress. I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessim…

There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing. Environmentally clean energy source is not enough, it needs to be ideologically pure as well.

Like Mr Fusion? runs on beer, from what I've seen.

Re: MIT-designed project achieves major advance toward fusion energy

#98

Post by uj8efdjkfdshf »

NiceWayToDoIT wrote: post #48

I remembered that in 2018 Japanese team manage 1200 T peak power. http://www.sci-news.com/physics/strongest-magnetic-field-ach... In comparison, 20T does not look much, but again it is, I wonder with the Japanese technique what is the highest continuous magnetic field.

These high magnetic fields are generated using flux compression[0], in which the incompressibility of magnetic field lines means that compressing the coils generating the magnetic fields will increase the strength of the resultant magnetic field. However, the implosion process permanently destroys the magnet, which makes it highly unsuitable for continuous use and certainly shouldn't be used anywhere near your fusion reactor.

[0] https://en.wikipedia.org/wiki/Explosively_pumped_flux_compre...

Re: MIT-designed project achieves major advance toward fusion energy

#99

Post by pfdietz »

NiceWayToDoIT wrote: post #48

I remembered that in 2018 Japanese team manage 1200 T peak power. http://www.sci-news.com/physics/strongest-magnetic-field-ach... In comparison, 20T does not look much, but again it is, I wonder with the Japanese technique what is the highest continuous magnetic field.

1200 T has a magnetic pressure of about 5.7 megabars (about 20x the detonation pressure of high explosives). Such high fields can only be achieved very briefly in devices that explosively disassemble.

Re: MIT-designed project achieves major advance toward fusion energy

#100

Post by mordymoop »

rnhmjoj wrote: post #50
anonuser123456 wrote: post #17

Earlier quoted context omitted.

> What's the catch this time? This is D-T fusion. Which means you have to have T. Which currently comes from fission reactor and has a half life of 15 years. So the plan is to use a molten salt blanket with Be to breed T. But Be isn’t scalable for consumption, so maybe lead eventually. That’s probably do-able, it just slows down the rate new reactors can come online since Pb is not as good a neutron multiplier. Once…

> But are they surmountable AND cheaper than existing nuclear or other energy sources? DT fusion solves the two biggest arguments that are always raised by nuclear energy opponents: storage of nuclear waste (it doesn't produce high-level waste) and safety (it's not perfect but it can't explode). I wouldn't call it a "meh", even if it comes off as much more expensive than fission.

I had heard that one of the major drawbacks of tokamaks was the incredible temperatures lead to situations where the smallest mechanical failure will lead to an explosion of hot, radioactive gas. Is that not the case?
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