Researchers Just Solved a Big, 70-Year-Old Problem for Fusion Energy (utexas.edu) 63
Fusion energy "took one step closer to reality," announced the University of Texas at Austin, as their researchers joined with a team from Los Alamos National Laboratory and Type One Energy Group and "solved a longstanding problem in the field" — how to contain high-energy particles inside fusion reactors.
When high-energy alpha particles leak from a reactor, that prevents the plasma from getting hot and dense enough to sustain the fusion reaction. To prevent them from leaking, engineers design elaborate magnetic confinement systems, but there are often holes in the magnetic field, and a tremendous amount of computational time is required to predict their locations and eliminate them. In their paper published in Physical Review Letters, the research team describes having discovered a shortcut that can help engineers design leak-proof magnetic confinement systems 10 times as fast as the gold standard method, without sacrificing accuracy... "What's most exciting is that we're solving something that's been an open problem for almost 70 years," said Josh Burby, assistant professor of physics at UT and first author of the paper. "It's a paradigm shift in how we design these reactors...."
This new method also can help with a similar but different problem in another popular magnetic fusion reactor design called a tokamak. In that design, there's a problem with runaway electrons — high-energy electrons that can punch a hole in the surrounding walls. This new method can help identify holes in the magnetic field where these electrons might leak.
This new method also can help with a similar but different problem in another popular magnetic fusion reactor design called a tokamak. In that design, there's a problem with runaway electrons — high-energy electrons that can punch a hole in the surrounding walls. This new method can help identify holes in the magnetic field where these electrons might leak.
I wished I had enthusiasm for this... (Score:5, Insightful)
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Re: I wished I had enthusiasm for this... (Score:4, Informative)
Itâ(TM)s planned to be 500MW, not 2GW, but Commonwealth Fusion Systems have a solution to the problem youâ(TM)re alluding to on their ARC reactor.
The problem is that fusion gives of neutrons, which smash into the reactor walls, and damage them. Worse, the damage makes the reactor radioactive over time. The bigger problem is that in the most common design (a tokamak), you need to build huge superconducting magnets tight around the outside of the reactor walls, which mean that to do maintenance, you need to take apart the reactor walls and extract them from in between extremely sensitive and expensive magnets, all while not actually standing there, because the area is irradiated. The even bigger problem is that the reactor walls need to be made of some pretty exotic materials because you need them not only to survive high energy neutron bombardment for a decent while, but also cool 500MW of heat on a relatively tiny surface area (after all the whole point is how energy dense these things are), and even more importantly, you need them to take those high energy neutrons convert them to more, lower energy neutrons, and then use them to breed tritium by smashing them into lithium. That means you need a bunch of beryllium to act both as a moderator, and to turn each high energy neutron into two lower energy ones. Meanwhile, the reactor has to resist the forces of enormously powerful magnetic fields trying to crush the thing.
So the tough situation. You have weird materials that need to put up with huge pressures, huge temperatures, high neutron fluxes. They need to breed the fuel, and then they need to be taken apart, and removed by robots through a letter box between huge magnets that canâ(TM)t be damaged. Big problem.
The solution CFS are designing and soon building is that their magnets are made from REBCO tape, and can have âoejumpersâ inserted into them that connect each tape across a gap in the magnet. They are then soldered on which makes the magnets very slightly non superconducting, but not enough so to make them problematic. Once youâ(TM)ve done this, you can split your magnets in half, which lets you crane out the whole of the inner reactor without opening it, set it down in a spent fuel pond, and crane in a new one. You then make your blanket out of molten salt (specifically FLiBe) which you pump through 3D printed cavities in the reactor walls. That means you can continuously refresh your coolant/moderator/breeder by just changing it out as itâ(TM)s pumped around the system. The reactor walls meanwhile can be made from a steel alloy that can survive the heat and embrittlement for a couple of years while conducting the heat into the FLiBe through a complex 3D printed structure thatâ(TM)s both strong and high surface area.
Thereâ(TM)s a couple of good talks about their plans on YouTube. Thereâ(TM)s this one that gives you the overall concept: https://m.youtube.com/watch?v=... [youtube.com] and then this one that goes into more details about exactly how you design the reactor walls: https://m.youtube.com/watch?v=... [youtube.com]
Both of those are at a more academic level because theyâ(TM)re from MIT PSFC researchers, but this stuff is actively being engineered and commercialised by CFS. Their demonstration reactor is well under construction, and the site for their first power plant is selected and will start construction soon.
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Every MSR operated more than briefly has had problems due to the salts. If MSR is their plan then they have a pretty high hurdle to jump with that.
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> Commonwealth Fusion Systems have a solution to the problem youâ(TM)re alluding to on their ARC reactor.
They do not.
Forget the reactor for a moment. Let's just talk about getting the energy out of some black box and turning that into electricity. For all realistic* designs, that's a Rankine cycle steam loop. Those cost about 50 cents per watt peak, and the associated transformers and switchyard generally push that up to around $1. In the case of a system where radioactively is present, you need to
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I am cautiously (and sadly) confident that before I die, some physicist is going to create a brilliant mathematical model showing that artificial fusion can't be practical for power generation, the model showing exactly why you're never going to get more out than you put it.
And a lot of fusion researcher are going to be very, very sad when it happens.
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We actually passed break even a number of years ago, so "never going to get more out than you put in" is already proven false.
Now we need sustainability, and a much better than break-even such that we can generate more electricity, enough to justify the plant.
I'm still not convinced that it wouldn't end up being like the scifi back in the '50s or so where the power plant ended up being on Antarctica and shipping power to the entire world because, well, it's a system that scales UP well, down not so much, so
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No we didn't. The amount of energy required to produce the lasers that hit the hydrogen pellet was 100x the output energy.
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No we didn't. The amount of energy required to produce the lasers that hit the hydrogen pellet was 100x the output energy.
What you are saying is correct, and in addition, that was an ignition experiment, not a an example of sustained fusion, however, that does not actually dispute the GP's main point. That was that there can't be a mathematical proof that "... you're never going to get more out than you put it [sic].". Perhaps a physicist can come up with a specific proof that there is some specific ratio of input energy to output laser energy that you can never exceed and combine that with a proof that there is some maximum r
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>That was that there can't be a mathematical proof that "... you're never going to get more out than you put it [sic]."
I am obviously talking about a complete controlled power generation system, not just a calculation about the point of ignition. Over-unity has been technically achieved, I'm saying it seems likely that it will never be practically achieved.
Neither the Sun, a fusion bomb, or even any 'over unity' technically achieved in the lab counts for the purpose of proving you can build a machine yo
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> before I die, some physicist is going to create a brilliant mathematical model showing that artificial
> fusion can't be practical for power generation, the model showing exactly why you're never going to
> get more out than you put it.
Well, Rider did in 1995 for all non-equilibrium approaches and most alternative fuels.
Re:I wished I had enthusiasm for this... (Score:5, Interesting)
Good point about the scalability and affordability. Getting past real world break-even (we've gotten past break-even in the sense of getting out more power than is put in if you only count, for example, the laser power used in ignition tests rather than the power used to actually generate that laser power) is the goal currently aimed for, but that would clearly not be the last hurdle to overcome. This article itself illustrates one of the problems to overcome. It specifically mentions that the problem being solved is how to contain alpha radiation inside magnetic containment. Basically, if you can keep it hotter inside the containment, you get more fusion. However, ultimately, if you want to generate power from it (at least through traditional methods, if no-one comes up with some other brilliant way to do it), it has to eventually leak so you can get some of the power on the inside of the magnetic containment to the outside. Some of that obviously happens through neutron radiation, which is not affected by a magnetic field (technically I think the spin of the neutrons can be affected, but they can't be deflected), and EM radiation including gamma which is also not deflected by a magnetic field. Those can heat shielding around the magnetic containment, and that heat can be used to generate power. Also, presumably when it gets hot enough, alpha and maybe a small amount of beta radiation will escape and heat the shielding. That presents a problem though. It means that there needs to be shielding and plumbing around the magnetic containment, but the technology generating the magnetic containment needs to either be inside or outside the shielding/plumbing. If it's inside, that means that it's exposed to a huge amount of radiation. A fission reactor uses relatively primitive mechanical control systems whereas there's pretty much no getting around having some sophisticated (and therefore delicate) systems creating the magnetic containment. It's hard to conceive of a practical way such technology could withstand being exposed to that level of radiation without very frequent replacement. If those systems are outside the shielding and plumbing, then the shielding, the plumbing, and the coolant flowing through it either need to have basically no magnetic properties (not ferromagnetic or diamagnetic, for example) or have a pretty insane (and possibly impossible) geometry that allows them to block the radiation, while allowing the magnetic fields to pass through. Maybe possible, but it would seem like a pretty hefty challenge. Most of the conceivable solutions to these problems seem like they would make operation very expensive.
Then, there's the fact that no-one has any plan currently for anything other than this being a drop-in replacement as a source of heat in a conventional fission power plant. In other words, a 1 GWe fusion power plant is essentially a 1 GWe fission power plant with a 3 GWt fusion reactor instead of a 3 GWt fission reactor. There might be some savings in the containment building not needing to be as physically tough, and there might be some savings if the construction and maintenance of the actual fusion reactor is significantly less than the construction and maintenance of the fission reactor, but it's not even clear that would be the case. Even if there is a savings there, there's basically little other savings in the rest of the plant (some money saved on cooling ponds and waste storage, I suppose). In the end, it is unclear that there would be any significant savings over a fission power plant of equivalent output.
Certainly though, if we can get fusion power working and the cost is not significantly more than fission plants, we should swap fusion power in for fission, possibly retrofitting existing fission plants. I should note though that fusion power also presents a bit of a dilemma for nuclear power advocates. Some of the real advantages of fusion power plants are that major nuclear accidents can't really happen. If magnetic containment fails, the reaction stops so instantly that the res
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Talk about burying the lede. Paragraph 2 is interminable and begs the question of why, but 3 answers it succinctly: Fusion fuel / waste risks are better.
Re: I wished I had enthusiasm for this... (Score:2)
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Pretty much everything is going to become uneconomical due to renewables, except other renewables. There will be niche applications where money doesn't matter, like naval reactors on warships, or fossil fuel power plants in places where they really can't deploy renewables... But everything else will go, and there will only be renewables (primarily wind and solar), and storage (primarily battery and pumped).
It's nothing to do with ideology, it's capitalism.
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I'm not sure how these things will ultimately scale...
There's a number of models for how a fusion reactor scales so any model I give will not apply to all variations on the theme. One model would put this as a cube-square problem. Consider a spherical reaction chamber than a more complex torus or whatever else has been proposed. Power output scales with the volume of the chamber, so that would be the cube of the diameter. Power input required would scale with the surface of the magnetic or electrostatic confinement structure, so that would be the square of
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... and since then, it has been demonstrated that the polywell basically didn't work at all. It might in theory, but when they built them the virtual electrodes the concept is based on turned out to be illusions, and when they considered that, the current needed to maintain them turned out to be infinity minus one.
Re:I wished I had enthusiasm for this... (Score:5, Interesting)
I still prefer flying cars as my favorite out-of-touch oft-predicted future technology. Totally ignored the economics of building such a contraption, the energy requirements to keep a car-sized object airborne, the noise pollution, and the fact that most people have enough trouble piloting a vehicle down on the ground.
But hey, for a brief moment it was fun to believe they one day the magic technology fairy was going to come and make all those problems go away, and we'd be zipping around the skies like George Jetson.
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1. Energy requirements to keep a car sized object airborne is totally handleable. I mean, just about every commercial jet is a lot bigger than a car.
2. Noise pollution - can be handled
The real problems is, as you mentioned, training, as you'd need a pilot's license for it, and that development has continued for both planes and cars - such that a hybrid between the two is going to be very lousy at both. It's not going to be crash resistant like a car, nor fly as well as a dedicated plane. The engineerin
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The energy requirements to keep a car aloft are wildly in excess of any available tech we have, beyond a very short trips.
Cars have to *stop*, slow down and other things a plane definitely can't do. Helos have *significantly* lower range for this very reason.
Can't claim plane capability when the very reason planes work is having very few vehicles and a huge infrastructure in ATC.
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The energy requirements to keep a car aloft are wildly in excess of any available tech we have, beyond a very short trips.
Did you... did you just arrive here from the 19th century? Do you agree with Lord Kelvin that "Heavier-than-air flying machines are impossible"?
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He said specifically car, not person carrying device. You need to move a sufficient mass of air per second which either means a lot of energy or a large area. That requires stationary wings which are large and inconvenient or rotating wings which are a bit less large but also inconvenient and dangerous.
I don't think small helicopters or light sport planes qualify as cars.
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We do have to consider though that, as a technical problem, autopilots are orders of magnitude simpler than self-driving. Following a flight path is child's play compared to following a road, especially if you have vertical takeoff and landing. Also, avoiding other vehicles is child's play compared to self driving since, unlike cars, planes are more heavily equipped with transponders, and are generally easily spotted with radar. Not to mention that FAA guidelines could be created requiring check in with an
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> I mean, just about every commercial jet is a lot bigger than a car.
Which is precisely why the energy requirements are tractable.
There are very few 4-person jets in the world, and those that exist are extremely expensive to operate. They scale with passenger capacity, which is why commercial jet designs continually scale upwards over time - consider the history of the 737 for instance.
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There are a couple of actual flying car designs now. They are based on multicopters, and they can take off from a parking space, making them actually flying cars and not roadable airplanes or some other such thing. But there's still no point because of the energy use. It still makes more sense to have the rich people who can afford to use them just hire a car to drive them around town when necessary.
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You are crazy bro, they are no more than 20yrs away now.
Re:I wished I had enthusiasm for this... (Score:5, Informative)
In any case, from the summary, while an advance, this would seem to be mostly a nothingburger as far as actually being a step closer to working power-generating fusion. It seems to simply promise a way to simulate magnetic confinement with less computing power. That does imply a savings in computing costs, but little else. That would make some of these projects a little cheaper, but would not make that much of a dent.
Of course, that's the summary, the article actually says that the approximation method used would actually avoid major errors that the current method makes. That implies that it would be qualitatively better. It also does not seem to mention reduced computing resources required for the method.
The abstract from the actual paper says:
This, while it says that it "outperforms" the traditional theory, does not seem to imply that it outperforms it in the sense of computational efficiency, but rather in the quality of results for high energy particles. That sounds a lot better than the slashdot summary and is more clear than the article. It also seems that this is specifically for Stellerators, with possible application in Tokomaks. So, ultimately it does sound like this could actually make for better magnetic containment, which could potentially increase the efficiency of the reactors. So it really is a potential step forward. How much of one remains to be seen, of course.
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All that really depends on whether there are factors inside the containment that would cause asymmetric pressure (for lack of a better word immediately coming to mind) on the containment. I'm not sure what factors could lead to that. I don't know enough to say whether or not they could exist. Without such factors, imagine a balloon that can't be popped (in that you can put a hole in it, but that hole doesn't propagate) with a pinhole in it. The balloon is going to deflate at basically the same rate no matte
not really a solution (Score:1)
At one point, (basically the 1950s when "too cheap to meter" power was the slogan for nuclear power) people basically thought of all the innovations that could come to society if electricity was free. Remember at the time that air conditioning was a rarity and homes had very weak electrical services. Trains ran on coal or oil. Factory work was done with legions of men.
Now, all the innovations in society that depended on electricity have come to pass. Pretty much everything that could be electrified has been
Re: not really a solution (Score:2)
Well said. Also, space won't save us either. At this point, the WEF dystopia of densified 15 minute cities with millions of people living like sardines in endless bland condo towers, with IKEA style compressed sawdust furniture and pseudofood almost seems like the better outcome.
We don't even need it (Score:2)
Fusion is cool and all but fission alone comes so close to the promises of fusion in terms of power delivery, we've not even come close to reaching the full extent of what can be done with nuclear fission today!
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Have they solved the economic viability problem? (Score:1)
Nope, they just got one step closer to building something that technically can do what it says on the side of the box, but ultimately may not be very cost effective compared against wind and solar.
If you're going to ignore economics, then the energy generation issue is a solved problem even without fusion. Just put a PV system on every roof.
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Just put a PV system on every roof.
Very few people will have roofs when they move you all into high rise commie blocks.
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PV also works very well on agricultural fields in hot environments. It provides desirable shade for both the livestock and the grass. Reducing water loss.
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livestock
Except livestock won't be a food source for the commie block people: meat supposedly wrecks the environment and democracy, and stuff. It's nazi food.
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Maybe solve that problem by touching some grass? While there certainly exist people who would ban the eating of meat on ethical grounds, many more people are simply concerned about the sustainability of widespread farming of animals like cattle which ultimately consume pretty outsized resources, which are only partly represented in the price of meat due to various kinds of subsidy.
In any case, when you get right down to it, most "meat" consumption these days is of heavily processed and adulterated "meat" pr
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It provides desirable shade for both the livestock and the grass.
There's this thing called photosynthesis ...
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Combining solar panels with agriculture of various sorts turns out not to be a huge problem. You simply have lower density of solar panels positioned so that they only provide partial shade. The position of the sun relative to the ground moves, so the shadow moves and, even when in shade from direct sunlight, there's ambient light. Not to mention that the panels themselves could be engineered to let some light through. There are also plenty of plants that do just fine in partial or even full shade. So, yes,
Re: Have they solved the economic viability proble (Score:3)
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I never understand when people say solar takes up a lot of land. Just use the parking lots.
And cover canals, and mandate it on new manufacturing plants... there's just so much low-hanging fruit before you get to residential roofs, and before you need to build solar farms. But corporations love to do big singular capital projects because they are easy and predictable.
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There's an idea: name it Trumpfusion and then Don will fund it.
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You might be confusing Fusion with Fission. Fusion has never had an economic problem because it's never had any usable designs.
On the other hand, you're right of course, batteries plus PV and Wind plus a lot more transmission are going to beat everything economically.
If Fusion does somehow work out as cheap to run then it would reduce the transmission costs that stack up with PV and Wind.
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You might be confusing Fusion with Fission.
There's already been quite a few experts weighing in with the projected operating costs to operate and maintain a commercial fusion power plant over the decades that they've been trying to work out the technology side of things. Fusion pretty much just solves most of the waste disposal problem of fission plants (neutron activation is still a bitch, though), but otherwise the expected operational costs of maintaining an active power plant would be similar, if not slightly higher. Clearly I pissed off some
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But many feel the potential to be cheaper is high as we get more experience with fusion. Stellarator is probably the most cost effective design if they can solve the tricky confinement. The first commercial models indeed would be roughly equivalent to fission plants economically because that's the starting level at which it would be economi
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Well, the bar isn't really set at the cost of fission, is it? Realistically, you'd have to get the cost of operating a fusion plant down to where it could serve as base load generation, so that'd mean it'd need to be cheaper than wind and/or solar, plus batteries.
Even I have to admit that I'm impressed with the progress that's been made in reducing the cost of producing batteries. Just in the EV realm alone, we've went from where they were just toys for the wealthy, to today where there's a few EV models
Misleading Headline (Score:4, Informative)
Re:Misleading Headline (Score:5, Funny)
Because of this advance, over-unity fusion will now be forever 5 years into the future instead of 50.
The Dogerator generates money for oil moguls (Score:1)
= We're fucked.
"One step closer" (Score:2)