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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

#311

Post by bildung »

AnthonyMouse wrote: post #273
ant6n wrote: post #257

Earlier quoted context omitted.

Again this assumes fusion power will be cheap. But in reality it may cost about as much as (fission) nuclear power. So yes it may help with making energy production carbon-free (together with solar, wind, hydro), but it won't necessarily create a some sort of energy abundance.

The theory isn't that the cost will be low, it's that the output will be high. If it costs the same amount as a fission reactor but produces ten times more power, that's lower cost per MW than anything on the market. Even if it costs more than fission, it could be competitive as long as the more it costs is less than the more it outputs.

But how should that gain in energy output be possible without making the whole system huge, too? The heat generating part of a nuclear power station only makes up a small fraction, most of the material is for transforming the heat to electricity and to shield off radiation. If you want to process more heat, you need more infrastructure to do so.

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

#312

Post by elihu »

fabian2k wrote: post #254
TrainedMonkey wrote: post #35

This is exciting. Magnetic field strength is a key component for enabling magnetic confinement fusion. This is because energy gain and power density scales to the 3rd and 4th power with magnetic field strength but only ~linearly with reactor size. See following equations for more details: https://youtu.be/xJ2h3vbOag4?t=306 So, why is this particular announcement exciting? There are 3 factors: 1. This is a high temper…

I'm curious if they can push the magnetic field even higher in the near future. For smaller magnets in NMR spectrometers 20 Tesla has been commercially available for 20 years. Of course this is more difficult for larger magnets. The new superconductors that allow these larger magnets are also very recent, not in discovery but in actual mass production. So they don't have as much experience with using these as with th…

I think so far the ReBCO tape is manufactured in small quantities by a handful of suppliers. If there were million-dollar orders coming in regularly, I suppose there'd be a lot of competition to develop the highest quality product. I expect it'd be like batteries; there's a lot of incremental improvements, and then once in awhile a major chemistry change. There's probably other high-temperature superconductors just waiting to be invented.

If I remember right from one of the videos from the SPARC reactor folks, they were experimenting with not bothering with insulation between the magnet windings. The ReBCO film is bonded to a layer of stainless steel, and they figured the conductivity of the film is so much better than stainless steel that they wouldn't actually get much loss from current leaking through. That seems kind of crazy, but I guess there's a lot of things about superconducting materials that don't behave intuitively.

Maybe manufacturers can make film that's bonded to a thinner layer of stainless steel or whatever, and thus allow for more windings in the same space?

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

#313

Post by drexlspivey »

qPM9l3XJrF wrote: post #309
mchusma wrote: post #112

Earlier quoted context omitted.

You are right, people who flippantly dismiss fusion just don't understand it. -Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not). - Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon…

"Fusion is in theory something that could give us true energy abundance." What does fusion give us that existing nuclear power plant tech doesn't?

The reactor can’t meltdown and contaminate the whole planet. Also there is no radioactive waste

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

#314

Post by nickik »

As a society we have failed to really use fission. Fission does basically everything fusion promises to do.

Fission has a absurdly high energy density, the step from oil to fission is far more relevant then the step from fission to fusion.

Fusion would mean basically no fuel cost, but thorium is already a waste product and even uranium fuel is a tiny part of any fission plant.

Some people seem to believe the fusion is inherently prove against weapons, but this is equally not really true. If you had a working fission plant there would be ways to use it to get what you want to make a weapon.

There are some places you might want fusion, mainly in space travel but even there we are not anywhere even close to where we could get to with fission. Open gas nuclear thermal rockets anybody?

In sum, I'm not against this reseach but its not a way to solve our problems anytime soon. Fission you could get to run with 60s tech and amazing reactors could be designed within decades and often with comparatively small teams in the 60-80s and somehow we haven't managed to make it competitive.

Fusion looks to be far more complex to build in every possible way. How this will be cheaper is questionable to me.

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

#315

Post by bildung »

pjerem wrote: post #225
tuatoru wrote: post #218

Earlier quoted context omitted.

Yeah, really, how? Fusion power plants still need land, buildings, generators, switchyards, wire, own power consumption, environmental impact reports, planning permits, regulations, inspections, and all the rest. And they need exotic materials and weird engineering in their construction. Really: how does fusion get us to ~1% (correction: ~5%) of current power prices? I've never seen a convincing explanation. Usually…

That’s about the same infrastructure than a nuclear fission reactor. And nuclear electricity is already pretty cheap. I don’t know how it costs in US, but in France, fully charging a Model 3 costs about ~5€ at night. That’s not 10x cheaper than gas but that’s a lot cheaper.

Retail electricity prices in France are €0,13/kWh, so not that cheap (€0,18/kWh pre pandemic).

https://www.statista.com/statistics/418087/electricity-price...

This doesn't matter, though, because France doesn't need many nukes anymore, therefore doesn't subsidizes new plants anymore. One new plant is built in France, and it already is hellishly expensive: "As of 2020 the project is more than five times over budget and years behind schedule. Various safety problems have been raised, including weakness in the steel used in the reactor." https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...

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

#316

Post by ncmncm »

choeger wrote: post #304
ncmncm wrote: post #290

Earlier quoted context omitted.

ISS is an apt comparison. Its apparent purpose while the Shuttle was flying was to be a place the Shuttle could get to. What it is for now is anybody's guess. In just a few years it will be a celestial light show, somewhere. I have no doubt that plasma fluid physicists will learn a great deal from trying to get ITER lit up. Just handed the money, they could have learned a thousand times more, and maybe even achieved…

"Just handed the money", my ass. Did you ever work in science? How to you even think that money should be distributed in scientific institutions? Everyone gets a share based on ... what? Their degree? Number of publications? Consensus by committee? And for comparison, look what the ISS has brought us commercially: We have a fully commercial manned spaceflight planned for next week. That is a massive achievement witho…

Handing 99% of the money to contractors for what will in short order be thousands of tons of radioactive slag contributes minimally to actual research. The developers of the overwhelmingly more practical FRC reactor are left to get by on scraps. Elsewhere in science, money is, in fact, being "granted" directly to scientists. This has gone on since long before you were born.

All of the "scientific work on" ISS is done with crew literally pushing an "on" button on each bit of automated equipment running it. Experiments are forbidden to involve more interaction, and also forbidden to operate without that "on" button, so the crew has something, anything to do.

Commercial manned spaceflight could better have been worked without ISS. ISS's role was nothing more than a place to take them. Plus, a huge money sink on its own. It will soon fall out of the sky, and with any luck not hurt anybody where it crashes down.

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

#317

Post by nickik »

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.

Very questionable if a fusion reactor is safer then a common molten salt fission reactor. I would argue that is far less likely to 'explode'.

And you can burn up the waste majority of that waste, the leftover waste after that would not really a huge issue.

Both of these are far more political problems then actual real problems a society based on modern fission would have.

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

#318

Post by ben_w »

filleokus wrote: post #292
codethief wrote: post #281

Earlier quoted context omitted.

> Fusion is in theory something that could give us true energy abundance. Well, at least for a few hundred years but then: > if you plot the U.S. energy consumption in all forms from 1650 until now, you see a phenomenally faithful exponential at about 3% per year over that whole span. The situation for the whole world is similar. […] the Earth has only one mechanism for releasing heat to space, and that’s via (infrar…

Huh, that's interesting! I wonder, in a strictly thermodynamic way (ignoring CO2 etc), how big of an impact it would have to remove all internal combustion engines in land-based transportation and power generation (coal plants). ICE's have like a 30-40% efficiency? Compared to electric engines 80-90%. But on the other hand, you probably consume quite a bit of energy producing the batteries...

Per battery or overall to the planet?

Per unit of storage, Wikipedia says the lifetime storage capacity of batteries etc. relative to energy needed to construct them is:

Lead acid: 5 times construction energy; Vanadium redox: 10; LiIon: 32; Pumped hydro: 704; Compressed air: 792.

I can’t remember where I’ve seen this, but I think a unit of PV produces all the energy it took to manufacture after a month or two.

If you mean overall? As a rough guide we emit about 35GT CO2/year which is about 9.5e12 kg carbon; burning carbon releases about 32MJ/kg; so about 3e20 J/year, or 9 TW, or 19 mW/m^2.

There’s more energy in the hydrogen in gases and oils, this is just a ballpark estimate of the thermodynamic output of burning that much does to directly heat the planet.

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

#319

Post by elihu »

sdeyerle wrote: post #10

In the original proposal for the ARC reactor, they were proposing making the magnet separable so the top and bottom of the reactor could be separated and the vacuum vessel removed. (See pg. 5 of https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0... ) It doesn't look like they are targeting that here. Does anyone know if that is ARC (not SPARC) specific, or if that has been abandoned?

I think that's ARC-specific. SPARC is a prototyping platform, they aren't designing it for long term use or to be refurbished.

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

#320

Post by nickik »

phscguy wrote: post #301
crazygringo wrote: post #145

Earlier quoted context omitted.

> I feel that fusion is one of humanity's best shots at actively reversing climate change Couldn't the same thing be said about current fission reactors? I get that fusion doesn't have the downsides of fission... but I'm also worried that people will be "scared" of fusion in the same way they're against GMO vegetables and irradiated fruits, totally irrationally...

Sadly no. While I think that it would work and probably be cheaper and easier than fusion, fission has an absolutely abysmal public image. People are terrified of radiation, even if the danger is very low. This means it becomes prohibitively difficult and hence expensive to build and run a fission plant because safety has to be prioritized so heavily. That is even if permission is granted to build in the first place.…

Fusion also produces radiation. So not sure why changing one word to the other should magically change public opinion.

We can just rename fission to #goodenergy or something, that would be cheaper then developing fusion.

People don't even know that nuclear reactors use fission, so the idea that this would change anything is crazy. People opposed will call fusion reactors 'nuclear' just like they do fission.

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