> The project, a collaboration between scientists at MIT and a private company, will take a radically different approach to other efforts to transform fusion from an expensive science experiment into a viable commercial energy source. The team intend to use a new class of high-temperature superconductors they predict will allow them to create the world’s first fusion reactor that produces more energy than needs to be put in to get the fusion reaction going.
“Always” is a long time, but its definitely fair to say that barring a series of unforeseen and radical breakthroughs in a number of disciplines, fusion as a reliable source of power is nowhere near being a reality.
Until they have a working prototype, this is the equivalent of vaporware.
Moreover, it's not clear if they will have a working reactor in less or more than 15 years, it's not clear if they are building a research reactor or a production reactor, it's not clear if they are going to collect the heat and use it to produce electricity, ...
Also, the article say that:
> A newly available superconducting material – a steel tape coated with a compound called yttrium-barium-copper oxide, or YBCO – has allowed scientists to produce smaller, more powerful magnets.
but if I understand correctly the new material is just a new type of superconductor wire that is more efficient than the current wires, it is not a superconductor magnet. If they have better wires, they can make better electromagnets, but it is confusing. Also is not clear if they have tested the new kind of magnets or it is just a theoretical application.
Also, 15 years is a lot of time, usually it means they don't have a clear idea of how to solve all the technical details. https://xkcd.com/678/
> but if I understand correctly the new material is just a new type of superconductor wire that is more efficient than the current wires, it is not a superconductor magnet. If they have better wires, they can make better electromagnets, but it is confusing. Also is not clear if they have tested the new kind of magnets or it is just a theoretical application.
This work is being done by the head of MIT's Nuclear Science department, in collaboration with most of the top grad students there. You can go look through all the publications that have resulted. They're going into great detail with practical engineering concerns, not just vague concept.
It's really disappointing and frustrating to me to see all the shallow dismissals here. The original article/press release didn't have much concrete information. But instead of making the reasonable assumption that some of the best people in the field actually know what they're talking about, and the article is poor, instead HN commenters are deciding their zero content, zero knowledge, shallow dismissals are more likely than what the experts are saying.
Nearly all the information about the ARC project is out there in the literature. If you don't want to read it that's fine, just try to have some awareness that you can't dismiss things without actually knowing what they are.
I've read too many papers published in peer review journals where a tiny advance is sold like a groundbreaking game changing advance, so I'm very difficult to impress.
The most popular cases of overstatement are the improvement of the batteries life and the cure of cancer. but there are similar bad reporting in less popular fields.
In this case it's easy to decide. We can just wait until April 1st 2033 and see if there is a tokamak fusion reactor that can break even without creative accounting.
At this point I’ll believe it when I see an independently confirmed measurement of a working prototype. This stuff seems to be perpetually 20 years out.
It’s worse. At least Linux _can_ be viable on the desktop. The challenges surrounding fusion are so staggering that putting any definite timeline around solving them is pure bovine manure.
Something that pretty much everyone in the world wants to see happen, but still faces a few technical hurdles, is much more likely to ever happen than something that is already possible but not enough people want, it seems to me.
Achieving ubiquitous nuclear power is more like achieving ubiquitous electric cars than achieving ubiquitous flying cars. It’ll probably happen any decade now, vs maybe never.
I think I grok what you're referring to when you say "political" but if anyone Dell came closest to fixing the financial problem with their Ubuntu laptops wouldn't you say?
Has Linux desktop caught up technically to Windows yet? The last time I used it there were still problems like double clicking a jpg from the Firefox downloads list opening an "open with" dialog pointed to /usr/bin or something. And it seems like where Windows will put things in places that might not technically be a perfect categorization but are convenient and make some sense, like monitor/video/screensaver properties from right clicking the desktop, this seemed to happen a lot less in Linux DEs. Aside from them seeming somewhat less responsive in general and lacking equivalent GUI system utilities to things like "Computer Management" or the device manager.
I'm not sure that the Windows desktop has caught up technically compared to many of the graphical shells available for linux desktops, it just depends on which list of things you value in particular.
I’ve been a subject of articles by tech press, several times. You have to realize that at least 50% of any pop sci article (and the vast majority of any “breakthroughs”) is straight up made up by the journalist for dramatic effect. I talked on the record to prominent journalists from established publications, who really should know better, and afterwards I just could not believe the fabrication and spin when the story is published. These people will pimp out their mom for clicks and ad revenue. So your best bet is a replicated experiment in a peer reviewed journal.
Like other fusion projects all of this is pure speculation, sadly.
However, I truly think it is wonderful that there seems to be a resurgence in the area of nuclear fusion. After Fukushima any project that had "nuclear" in its name was put on hold for political reasons and it's good to see that people don't have cold feet anymore.
Nuclear fusion substantially eliminates the "meltdown" risk associated with contemporary fission-based nuclear energy sources.
But it's no panacea [1], there's still substantial radioactive waste produced and radiation hazards to those working near the reactor.
If you operate under the assumption that we should pursue nuclear energy, then this is great. But if you operate under the assumption that between solar wind and storage, we have everything we need without any radioactive waste or radiation hazards to workers, this is pretty uninteresting beyond academic purposes.
> In general terms, fusion reactors would create far less radioactive material than a fission reactor, the material it would create is less damaging biologically, and the radioactivity "burns off" within a time period that is well within existing engineering capabilities for safe long-term waste storage.
There's really no comparison; fusion is vastly cleaner and safer.
I think the problem here, is that all those environement protection groups fighting fission, would cease to be after they "won" and thus are desperat in search of a new "evil".
Has there ever been a activist group that stated loudly: "Yes, we pulled it off"- and then peacefully disolved, with the promise to reunite the day the defeated cause should return?
As a freshman at MIT in the 1980’s, I was impressed to hear the announcement that the MIT Group Against Smoking had just disbanded. They had accomplished everything they set out to do and felt their were better places for them to invest their time.
And yes, I vividly recall the only time in my tenure at MIT I saw a student light a cigarette. It was in 10-250, the person was sitting audience right side of the lecture hall, about 1/3 of the way back in the room. She did so once, on her first day of class as a transfer student.
So yes, change can happen, and be recognized, and the activists move on.
I just have a very negative counter-example here though: It was a radio-interview with a green-peace activist on ITER. And they would go to great length, to put the nuclear waste problem of fusion into the same category as the nuclear waste dilema of fission- although the fusion byproducts decay down to zero in 300 years- which is near nothing next to fission.
I really rooted for greenpeace once, but such intellectual dishonesty- with a fundamentalistic approach, expecting humanity to give up civilisation as we know it, instead of working with the humanity they got- lead to a deep distrust to everything they publish.
Steven Pinker put it better then I could have when he wrote:
No one has ever recruited activists to a cause by announcing that things are getting better, and bearers of good news are often advised to keep their mouths shut lest they lull people into complacency. Also, a large swath of our intellectual culture is loath to admit that there could be anything good about civilization, modernity, and Western society.
My favourite example is this that in Australia we have no nuclear electricity generation large as a result of the good intentions of Greenpeace and The Wilderness Society, the later of which is largely responsible for there being no new hydro electric power stations in Australia after they were success in blocking the Franklin River dam project. That and there being pretty much no good sites left.
That realisation and my ensuing confusion resulted in me withdrawal from the whole debate with the hope that greater minds will work toward improving the situation.
I don't disagree, but this is saying more about how miserable nuclear fission is than anything else.
If we have a path which involves zero radioactive waste, and zero biologically-active radioactive effluents, obviating the need for nuclear anything - why would we bother?
Assuming that path is actually viable, which is debatable, that path might have other risks. It's not clear a priori where the total risk is lower. IIRC, wind power has, for example, a rather high accident rate for workers. Impact on birds was also something discussed. Massive solar power plants in Africa, for example, have an associated political risk.
You are willfully ignoring the fact that all forms of energy pose hazards, and that the hazards posed by other forms of energy are vastly higher, usually several orders of magnitude.
And you are reacting emotionally, "oh my god, nuclear horrible bad", rather than looking at the numbers rationally. If you look at the numbers, nuclear energy is incredibly, almost comically safer than any other form of power, including rooftop solar. Yet the public perception is exactly the opposite.
The evacuation of the entire prefecture was almost certainly an overreaction, due to exactly the incredible over-weighing of the dangers of radiation. Yes, radiation is dangerous, but not that dangerous, and the main negative health effects (and deaths) were from the evacuation!
Look at the WHO reports on Chernobyl. They published a report every ten years after the accident, and in each report they dramatically lowered their estimates of deaths due to radiation effects, and in each report the negative health effects of the evacuation became more clear.
"The only thing we have to fear is fear itself". -- FDR. With nuclear power, the fear of radiation is currently a much greater threat than the actual radiation itself.
The title is the worst kind of deceptive, clickbaity, untrue crap. As usual, MIT is the hub of both exciting science/engineering, and horrid press releases.
The first paragraph and the sub header is an outright lie:
“Carbon-free fusion power could be ‘on the grid in 15 years’”
And then later:
“Prof Wilson was also cautious about the timeframe, saying that while the project was exciting he couldn’t see how it would achieve its goal of putting energy on the grid within 15 years.”
Only slightly related- but what endevours would become at how much energy output per $ Helium inserted viable? Has that been studied?
There must be a curve, where it can be estimated at what cost-point fission and solar are out- and for example growing ressources in vats becomes cheaper then farming/ chopping down natural grown wood.
What other "uneconomic" endavours become feasible with fusion at what price?
Carbon sequestration - not sure on what price point, but at least the current cost of oil reserves. This factor should include national security 'returns' (the huge boon from moving away from middle east controlled energy) - so say trillions of dollars per decade.
Salt water desalination - at some point pumping salt water (possibly long distances) to desalination plants for agricultural and domestic use becomes feasible.
Space programs - once oil is disrupted as an energy source for the masses it will be cheaper to push things into orbit.
Mass transit is public transportation, not all transportation. Many rockets use fuels derived from oil and other fossil fuels, e.g. kerosene and methane.
I meant mass transportation in the general sense, cars, busses, trains, planes. I just kind of typed the wrong thing.
This article[1] claims Falcon 9 launch list price is $61.2 million and "Musk said the fuel used on a Falcon 9 is between $200,000 and $300,000."
So the fuel cost is 0.5% of the launch price.
It could be argued that if we stop using oil for transportation the price of oil derived kerosene and methane could go up as production scales down and fewer refineries sell in to the market.
> Let's combat global warming by producing even more heat, converting 40% of it to electricity.
All the wattage produced by humanity is utterly insignificant in the face of the energy we receive from the sun. It will still be insignificant if we double it.
(We receive about 2 × 10^18 watt hours per day from the sun at the ground. Daily human energy production is about 5 × 10^15 watt hours.)
In that scenario, we are doomed anyway: If we would generate anywhere close to that level of power via solar, we would change the albedo of earth significantly -> heating. And we would certainly affect the air currents on a global scale if we use wind power to that extend.
> (Now consider that in the golden age of oil before the oil shocks in the seventies, oil consumption was growing more like 8% per year.)
At that time, per capita energy use in the US was growing by 3% per year while population would grow by 1.5% per year. Today, per capita energy consumption in the United States is falling, and the population is growing more slowly. The story is much the same elsewhere. Even China has leveled off in per capita energy consumption. India's is still growing, but it will take many years considering their baseline of 1/10 of the United States per capita before they're the biggest problem, and I guess they'll probably turn that trend around before they actually get to that point.
In addition, it may be possible to put surplus energy into atmospheric greenhouse gas fixation, if such technologies are fruitful. In essence spending more watts to reduce future retention of solar thermal joules.
Assuming widespread deployment of fusion reactors and use of battery powered vehicles for transport, humanity's carbon footprint would decrease by about one or even two orders of magnitude, which is the real culprit behind anthropogenic climate change. Obviously that's not something that can happen overnight.
Saw this video explaining in a HN comment why stronger magnets and a different approach might make fusion work. After ca. 22:00 Minutes he is done with the fusion basics and explains the new approach. https://m.youtube.com/watch?v=KkpqA8yG9T4
Man, this was excellent. If you're passing by, definitely give this a watch. The speaker makes the material clear and understandable for the complete layman. Very exciting.
At one point he briefly mentions (almost in an off-handed way) the issue of scaling the novel semiconductor production approach. Would be interesting to know how big of an ask that really is. Maybe I'm jaded by current events but figure it's only a matter of time before the science community has its Bernie Madoff moment. Especially in light of how renewables seem on the cusp of their moment to shine.
Extremely hard, the superconductors are a ceramic that is very brittle, it's quite hard to make a nice wire out of it. If a single break in a long length ruins the whole stretch then scaling up would be massively challenging, you can't just rely on melting and cooling to nicely even out issues during drawing a wire.
This exactly misses a significant feature of these new, high temp and high field superconductors: they are a mass manufactured flexible steel-backed tape. These are not the old ceramic superconductors.
I don't know why this isn't the top comment. I came in a skeptic but that video really put to rest my doubts that these new REBCo superconductors are truly a breakthrough. The new designs they enable make ITER look like a massive obsolete waste of time. Sounds like the only hurdle now is 5 billion in funding needed for a prototype. Its no longer "50 years away", its now "5 billion away".
Serious question: what could be the cost of fusion generated electricity if the reactors go mainstream like fission reactors? Unlike uranium, hydrogen is for free and there is no cost associated with storing burned fuel. You can probably also save a lot on safety systems. But you still probably need a badass reactor with auxiliary power source, huge steam turbine and cooling towers. Or not? What factors will determine the cost?
Even if we assume for a moment that we got it working, the factors are: scale and embrittlement. Current thermonuclear technology, theoretically, breaks even, energywise, on reactors of certain scale. There is a reason to believe that once we build a reactor of a certain size, the energy output of a reaction will be bigger than the energy spent on jumpstarting it and magnetic containtainment. embrittlement of reactor structural materials is caused by radiation. After a while, reactor has to be rebuilt from totally new materials.
>After a while, reactor has to be rebuilt from totally new materials.
The closest parallel we have is nuclear reactors. Navy Nuclear submarines are probably the most prevalent safe small reactors (US submarine reactors not K19) and they have significant lifespans extending across multiple decades. (source: passed my navy nuclear engineer exam in a past career) The resulting embrittled can/containment does need to be handled safely, but this is a capital depreciation that can be modeled and planned for.
The MIT design essentially solves those two issues. Scale is smaller with stronger magnetic fields, and embrittlement is confined to an inner wall which is easily replaced once a year.
You are correct! It’s maddening that you had to make the correction, though. Commenters in here seem incurious about the new developments detailed in the source material.
There are fusion designs that heat water and there are some that can capture electricity directly. Who knows which will prevail but the the latter should be cheaper and more compact. Maybe so compact that it could be used on ships, trains, or spacecraft.
Tritium. In addition to the points made by other replies, current fusion is (mostly) D-T, and we’re nowhere near breeding T in the reactor, so it has to be made in fission plants. Tritium is very expensive, and a significant risk for nuclear weapons proliferation.
This will probably end up pushing us to Lithium fusion pretty fast, the fuel is a lot more common and the temperature requirement is only a little hotter.
That said nuclear proliferation from tritium is a lot less of a risk than from uranium. Anyone can put together a nuclear event with sufficient enriched uranium, pinching tritium to fuse using a fission event, well it's a significant technical hurdle.
Nobody has a clue, because we haven't figured out how to build a reactor that generates net positive power at all yet. The cost of the fuel is trivial, but there's no telling how much it will cost to mass-produce and maintain stuff like superconducting magnets, high-grade vacuum systems, whatever we end up using to contain the massive neutron flux, etc.
I am all for fusion but I am curious, what happens if there is a magnet failure and the plasma, which is "...hundreds of millions of degrees celsius," escapes the containment vessel?
What damage will it do while it's cooling off for whatever period of time.
It would explode, but for any reactor we’re likely to build in our lifetimes, it wouldn’t be anything like a nuclear bomb. We’ve had nastier explosions in natural gas refineries. There would be radiological contamination from the Tritium and any neutron-activated material, but it would be more of an expensive cleanup than an environmental disaster. It would be dirty though, especially if the reactor had been running for a while, building up dust. What wasn’t radioactive would still likely be stuff you don’t want to breathe or ingest.
TL;DR Boom lots of dead people in the containment structure, expensive cleanup, but nothing like a fission disaster. It would be an uninspiring explosion, but it would be dirty.
This is wrong in every possible way. There isn't enough mass of hot material in any plausible fusion reactor to even breach the vacuum chamber.
Or for better context: research facilities today regularly lose plasma containment. It's why we don't have practical fusion reactors, but they're already at the plasma densities we would run at (which is an order of magnitude or so better then the Sun achieves).
Yeah. There's even a clue in what it's called: a vacuum chamber.
Densities are extremely low, so you only have a few grams of material in the reactor, even at large volumes anticipated for a commercial design.
Furthermore, the reaction is extremely finicky, as demonstrated by what an incredibly hard time we are having creating and more importantly sustaining it. Any deviation from the ideal and it just goes out. So no runaway chain reactions.
From what I understand I think don't know and it hasn't been extensively modeled because we are still trying to just get the process to start. Having said that I think that if the reactions containment breaks the actual fusion process breaks down super fast and cools much faster then something like a meltdown at a fission reactor. If any more qualified wants to refute any of this please do.
It's actually an incredibly small amount of material that is heated to millions of degrees. It is a drop in the bucket compared to the amount of matter in the immediate surrounding environment, so the energy can be soaked up relativity easily.
I think I remember hearing something like that anyone more than 50 feet away would be completely unaffected (but don't quote me on that).
The plasma hits the wall, cools rapidly and you have to deal with hydrogen gas and a slightly warmed wall. The thing about fusion reactors is, that the energy densities at any given moment are actually not that high at any given moment, it is just that the fuel cycles are quite rapid and consequently you can get a lot of energy out.
Meta rant: I would like people to remind themselves that HN's rules explicitly disallow shallow dismissals. Unfortunately this comment section seems to be nothing but.
The material science behind high temperature semiconductors has undergone radical changes in recent years. The techniques being used are largely well understood science and the downsides of previous approaches like ITER are explicitly avoided. There has been a visible explosion of commercial activity in recent years.
People bander around the "always 20 years away" moniker as if we should put today's estimates on the same grounds as the guesses from those early 1970s projects that were never even properly funded. People were not screaming "20 years more" at the turn of the century.
You don't get to discount something as potentially groundbreaking as this just because it's taken a little while to get here. Either put up or shut up. I would love to hear genuine substantive conversations here, if people were willing to have them.
I can offer some economic perspective. Oftentimes the critical advance for technology to reach deployment is not a theoretical breakthrough in the primary science but rather a change in aggregate costs, ability to organize capital, secondary technologies, etc. It's stuff that pushes the tech past a threshold of feasibility. The Industrial Revolution itself, for example, was a mix of recent breakthroughs and older ones that started to be realized enmasse(e.g. coal mining and steam engines co-evolved during the 1700's).
So when researchers say, "this supporting piece of the puzzle has gotten much easier," as it is with the new magnets described in the article, that's actually a good time to listen since it might be the tipping point. Theory developments or experimental observations are exciting stories to read about but often have less imminent bearing on whether you're going to see it impact your life.
Could you recommend any resources (articles, books, podcasts, etc.) that go into more detail on the economic factors that come together to enable periods such as the Industrial Revolution, or really any period?
I think economics offers a great perspective to subscribe to, but haven't found much opportunity to learn it. Most "economics" podcasts are really just business-focused and describe modern events with little insight into the economics behind it.
The best fast and fun one is "How We Got Here" by Kessler, I think it's free if you send an email. Draws a really clever line of related inventions from swords to microchips.
Specific areas after that...
"Brilliant" by Brox on the history of lighting.
"Salt" by Kurlansky.
"The Master Switch" by Wu on telecoms and broadcasting.
"Ascent of Money" by Ferguson has some critics, but it's got some great historical anecdotes on the history of financial tools, like fractional reserves and insurance, weirdly captivating.
Those are all economic history... If you really want a pop intro to econ principles, maybe Planet Money? Pretty much everyone should listen to Planet Money anyway, it's just great radio.
I gave Planet Money a shot but found the two hosts nearly unbearable and the typical NPR heavy-handed production and jumpy editing distracting.
They try so desperately to make the topics sound fun/accessible that it ends up sounding like a disingenuous forced comedic act rather than a natural, education conversation with the guests...I guess I'm not the target audience for this.
But I love the book recommendations. I plan to read that Kessler book tonight.
I thought Douglass North's textbook on economic history was useful when I studied it in school, and he likely has a lot of other articles and books you can pick and choose from. He died in 2015 but was quite prolific and won the Nobel prize. I have the last book he co-authored on my shelf that I still need to read.
You might be interested in the book "The most Powerful Idea in the World" by William Rosen.
It's common to point to technological advancements such as steam which gave way to the Industrial Revolution, that Britain had coal etc. And that's definitely important because steam powered factories which was a major change from household/hand/craft businesses.
In truth there were many contributing factors. But why Britain? Why was this the place where all these inventions were being made? Some historians get very creative in additional reasons for how this era came to be. Rosen makes the really interesting claim that it was the idea of intellectual property that triggered all the inventing-- that man could own an idea and make money from it!
-Sputtering of shielding and every other part of the reactor from fast neutrons. If your reactor is becoming brittle as it’s in operation, and requires constant maintenance, it won’t be operating enough to be cost effective.
-Breeding blankets. If we’re not breeding tritium in the blanket (and no one has been able to sustain a reaction that way yet) then we’re just using fission a lot. Expense becomes an issue, as does radiological issues.
-The plasma diverter is very much an unsolved problem. I can get into more detail here, but in short this is the part of the reactor that “skims” some of the hot plasma off to do the work. The dynamics of very hot, magnetically constrained plasmas still escapes us, and when you throw a rock into that stream, the complexity increases. Current divertes wouldn’t last a day in an operating plant. Disassembling your whole plant every day and reassembling it is a non-starter.
-Containment of plasma at sufficient energies is still something measured in seconds, or fractions of seconds. The usual metaphor is trying to uniformly squeeze a balloon; it will just “squirt” out. For s research reactor a second or two of fusion is an achievement. For power generation it’s nothing.
-Neutron activation of otherwise inert materials means you’re going to have serious radioactive waste. It’s unclear just how dirty D-T fusion would be from soup to nuts, but “pretty dirty” seems like a good bet.
-Tritium penetration.
-Most of the energy produced is in the form of neutrons, and we don’t know how to use that as a source of power. Those neutrons, in addition to destroying the reactor itself and activating materials, represent a loss.
-What we really need is aneutronic fusion through alternative cycles to D-T, like p-p, but that’s a much hotter plasma and no one has a clue how to make it work yet.
-Coolant for a constantly running reactor is a boring, but unsolved problem.
There’s more, but these are the ones most poeple on HN probably are aware of when they dismiss this article.
And if we’re willing to deal with that waste, then we already have a viable source of atomic energy from fission! The future is whenever we decide to deal with the problem instead of leaving it pools or casks to solve itself.
@csallen: Be willing to actually dispose of it. We need to commit the money and political will to set up a single disposal site. Right now it’s a NIMBY nightmare so we get the worst outcome.
My thinking is more around using thorium cycle nuclear reactors which consume almost all their input material [1].
1T of thorium produces the same amount of energy as 35T of uranium or 4166000T of coal. 83% of the waste products are inert, and 17% require only 300 years to reach background levels of radiation. Much safer than uranium cycle too.
This technology is very promising IMO, though given the general attitude people have towards nuclear, it's not surprising it is underdeveloped, more research is needed.
If I could I would nominate you and your descendants up to the nth generation as a willing custodian of all the toxic waste that we have today since you are so keen in increasing it rather than stopping this aberration.
Honestly it’s really shameful to see such short sighted comments here of all the places...
It’s still a couple of orders of magnitude or more better (in terms of half life of the byproducts).
So if anyone knowingly compares fission waste and fusion waste putting them on the same plane is simply lying.
Or they recognize that for a human and generations of their descendants, 30,000 or 300 years doesn’t change anything for them. Either way it’s longer than the US has been a country for one metric. Both cases require similar solutions, long-term containment, and so both run into the same political inertia fielded by NIMBYism.
To claim otherwise is, as you would have it, lying.
More importantly, both are solved issues from a purely technical standpoint, it’s just that everyone wants someone else to deal with it. As a bonus, we can actually use fission to produce energy, right now. There’s no issue of, “it will be great when...” grid storage is solved along with intermittency for renewables. There’s no, “it will be great when...” fusion is producing energy rather than heavily parasitizing from the grid. There’s no waiting until we’re completely screwed by climate change effects.
I spent several hours watching MIT's presentations about this reactor design.
- The inner wall of the reactor is 3D-printed and replaced annually. This is easy because they've found they can make joints in the superconducting tape that add very little resistance, allowing them to include hinges letting them open the reactor.
- Surrounding the inner wall is FLiBe molten salt. It's heated by the neutron radiation, acts as coolant for the thermal cycle, and as the breeding blanket (each high-energy neutron releasing two neutrons from impact with beryllium, providing plenty of neutrons for breeding tritium from lithium). Having a liquid blanket makes tritium harvesting easier.
- Stronger magnetic fields damp down plasma instabilities, making containment easier. For years MIT has been running the Alcator C-Mod, which has more powerful fields than any other tokamak in the world, so they have some direct experience here.
- The neutron-activated wastes would only need containment for several decades.
(I don't know anything about the diverter, and I'm interested if you want to get into more detail.)
The MIT folks argue that we understand tokamak plasmas much better than any other configuration, and have gotten far closer to breakeven than alternative designs, so that's where we should focus.
However, there are some projects working on aneutronic fusion, mainly with p-B11. The biggest project is Tri Alpha, with $500M invested. They've achieved stable plasma at 10M degrees, and are about to start testing a new reactor which should reach 100M degrees. If the plasma continues working as the expect, they think it's a straightforward path to a production reactor; of course there could be surprises.
Another approach is laser fusion with petawatt picosecond lasers. We're not far off from having a laser with the specs to attempt this, and these lasers improve by a factor of ten every three years.
Helion, funded by YCombinator, is attempting a hybrid D-D/D-He3 reaction. (The output of D-D is half He3, and half tritium which decays to He3 with a 12-year half-life.) They say the hybrid reaction would release only 6% of its energy as neutron radiation. I don't know how it's going though.
I've had a quick shufti through the comments so far and I don't see too many "20 years" and anyway the meme was always 50 years. That said, I am with you - I think the 20, 25, 50 memes are badly wrong.
"People were not screaming "20 years more" at the turn of the century." - which century? I went to school in Oxfordshire, UK (later half of the 1980s) and studied physics to A level and went on a field trip or two to the local nuclear fusion project.
I clearly remember being told by everyone there how progress was measured. It seemed to boil down to a chart with time on the x axis and factors away from sustainable fusion on y. This may have been a "lies to children". The chart looked like an exponential decay with a rather wobbly tail starting in the late or so 1970s back then.
There is a good reason for the 20/25/50 years meme. It's the best model we have had for progress for a very long time. I will be ecstatic to get my 'leccy from nuclear fusion in my life time and unimpressed if my grand daughter is still waiting.
“Prof Wilson was also cautious about the timeframe, saying that while the project was exciting he couldn’t see how it would achieve its goal of putting energy on the grid within 15 years.”
My father was 14 when Ivy Mike blasted Elugelab below sea level. In 1982, I took my first college course. We read Herman Kahn's The Next 200 Years. Tokamaks were promising. I shared my seventeen year old enthusiasm for the fusion future with him. He introduced me to "Always twenty years in the future." He'll be 80 next month. The article's optimistic 15 years is 2033. For Dad, that would put it just over four "Twenty years in the future." For me, it would only be two-and-a-half. Sure there's a reasonable chance that the "always" in "always twenty years in the future" will be wrong some day. I'm skeptical this is that day because the basis for today's prediction is that the future is just like the present only more so. The article is a press release not science.
The just-over-the-horizon timeframe normally cited is 30 years, but the MIT team believe they can halve this by using new superconducting materials to produce ultra-powerful magnets, one of the main components of a fusion reactor.
Halving the just-over-the-horizon number isn't progress. It's marketing.
>People bander around the "always 20 years away" moniker as if we should put today's estimates on the same grounds as the guesses from those early 1970s projects that were never even properly funded. People were not screaming "20 years more" at the turn of the century.
Well I think people have great reason to be skeptical. I hear "Fusion is around the corner" at least once a year. Usually it is by smaller companies but every once in awhile it is the bigger ones.
So let's look at the big one. In late 2014 LOCKHEED MARTIN announced that their compact fusion device would be demonstrated in a few years and have an operational prototype by 2019 [1]. Even Scott Manley has the top comment on that video as ""high risk" = we don't actually have it working, but there's a chance we could." Even in the video suggests it wouldn't get onto the grid by 2034 (20 years from their announcement).
So maybe you're right, it isn't 20 years away, only 16. Which serendipitously lines up with the 15 years claimed in the FIRST SENTENCE. Which is then given many asterisks at the end and doubted by the lead scientist.
TLDR: People band around "it is 20 years away" because experts are still saying "it is 20 years away." (including this article)
End note: That being said, I don't want to downplay the improvements. We are SIGNIFICANTLY closer than we were in the 80's/90's. Several of the major problems have been improved upon. And I do think I will see fusion on the grid in my lifetime. More so, I really think it will happen within 20-30 years.
As a serial offender, I think you're right to say this but there is the other side of the coin. Fusion is littered with giant claims, and huge funding holes. Skunk works are very cool but it's as far from contestable science as it's possible to be: the skunkworks doesn't want to be put underneath a critical microscope because its looking for exploitable trade secrets and patent material.
Groundbreaking is usually overused. How many genuinely groundbreaking things emerge from press releases as opposed to deep investment by state backed actors? Seriously, Edison (for instance) was a wizard at commercial applications but frankly useless as a scientist.
I call Leo Szilard groundbreaking. He really did have a flash of insight.
Crispr didn't just happen. It took a shedload of prior work. FMRI is groundbreaking except they're all walking back from the pop sci stories into more fundamental tests.
So is this stuff really worth substantial conversation? Who is going to invest in chatter here? MIT and Lockheed won't, for obvious reasons. And I doubt jet or iter scientists will, for other obvious reasons. Who is left who would meet your criteria?
I agree with you regarding shallow dismissals, provided the claims are deep to start with.
In this case, we start with a headline that the most transformative technology since combustion is just around the corner.
The basis for that claim? That they are going to create an experimental reactor using new high-temp superconductors.
Well ok, great. But this is just a lame press release about how somebody HOPES it will work. It's not even a technical argument: it's basically a business argument, using currently available technology. Just the nuclear power version of the "suits" article that comes around every year, and that PG called out in 2005 [1]
So what, exactly, can a person substantively say against /this/ piece? I would argue: practically nothing. The best points raised by others relate to fusion in general, which we could have had without this submarine PR piece.
> The techniques being used are largely well understood science and the downsides of previous approaches like ITER are explicitly avoided.
I'm a layman when it comes to these things, but does that mean they have improved tokamak's or will future nuclear fusion reactors more look like the stellarator used in Wendelstein 7-X for example?
Actually, you can easilly discount this, since they haven't run the experiment yet. Until that happens it should be fully discounted. Happy to pay attention when the experiment is run.
Long to short, a couple years ago, I was out for drinks and bumped into a friend. She was having drinks with a friend who is a prominent researcher at Princeton Plasma Labs.
We got to talking. He assured me they were getting closer and it was only a matter of time (read: money). I'm not a politician or an investor, etc. so he had no motivation to blow smoke up my arse.
Umm maybe justifying his life’s occupation would be motivating, not to mention in the company of a female friend and alcohol? “Yea bro it’s always 50 years out lmao” not to be expected from a PPL researcher...
Maybe I'm naive, but I honestly don't understand why governments and private foundations alike aren't throwing money at Fusion scientists. It seems far and away the best possible investment one could make today in humanity's future.
It's also a tough sell since it seems like science fiction whereas roads, schools, medicare, social security, etc are current tangible needs that people understand. I'd venture to say at least 50% of the American population believes you can get sick from being outside without a jacket and so trying to explain to them why you spent most of the budget on fusion would just make people's heads explode.
There are probably many papers in semicondactor area, but it is hard to build company producing consumer CPUs. The same is for search engines for example..
Throwing money at a problem gets you "more", not "better". If your problem is that you need more scale, then throwing more money at a problem will get you that scale. If what you need is a breakthrough, feeding more money tends to lead to more heartbreak (see, e.g., Alzheimer's--we've spent several billion dollars on a cure and the only thing to show for it is that reducing amyloid plaques doesn't seem to do a damn thing). Fusion is still very much in the latter category: we don't have a working fusion reactor we need to make feasible, we have a vague sketch of one that might become a feasible reactor, if we achieve a few breakthroughs (and even then, we have several more issues to work through to actually make it economical).
I didn't downvote you because I find your assertion about throwing money at a problem to the point. Others have downvoted you perhaps because your other assertion that there's no working fusion reactor might be unfounded, in other words, we might have already working fusion reactors but they are just not yet profitable. (I am not an expert.)
having been to an international fusion science conference, and a good friend having being a 30 under 30 fusion physicist, who is now at princeton advncanced fusion lab d3d and general atomics----
my beef with fusion is that people think that if we 'discover' how to pull off net positive fusion that it will suddenly result in limitless energy as opposed to a slow and centuries long process to make it profiteable.
sustainably profitable fusion is NOT likely to explode in usefulness the same way nuclear fission did.
we might discover how to sustain net positive fusion, but scaling it up in any single reactor might prove problematic and fusion may wind up being a very hair problem to improve to high levels of profitability and energy production for a long long time after fusion sustainability is 'discovered'.
from a purely economic perspective, fusion and fission have zero reason to exist for economics.
fission makes sense for fuel density for powering weaponized systems in space and at sea and remote locations.
fusion would be filling the same precise needs at best, otherwise, in a world where there is limited resources to invest in R&D for global energy research for powering cities and civilizations commercial and residential energy needs, our money should be going into making our consumption more efficient, and our existing sources better.
solar, wind, natural gas, hydroelectric, coal and other existing sources should all be made more efficient. we simply don't need to invest in 'new' energy sources like fusion. they are redundant from an economic perspective.
and energy transmission, distribution and STOREAGE all need massive amounts of new R&D investment.
Just one thought: I am glad that there are people who are trying to solve extremely hard problems even if they will never see success themselves. I much prefer money and intelligence being spent on fusion than on developing new weapons or technology to create perfect surveillance so more ads can be served.
As far as I understand fusion is at a point where we know almost 100% it can be done but there is a long list of hairy problems to solve. Working on these is money well spent in my view.
The design of the ARC reactor in the 2014 arxiv paper produced 500 MW(th) fusion power. The FLiBe bath contained some 90 tons of beryllium. The annual world production of Be is just 220 tons. If the world's entire estimate resource of mineable Be (100,000 tonnes, according to USGS) were used to make ARC reactors, they might supply 1% of the world's primary energy demand.
The FLiBe also contains about 1/4 the 6Li produced by the entire US hydrogen bomb program. The facility that enriched that lithium used 10,000 tons of mercury and is an environmental problem even to this day because of leaks. That process is also now illegal in the US due to this pollution, and there is no facility in the world that could make that much 6Li.
Perhaps those problems could be worked around, but there's a deeper issue. The power density of the ARC reactor is around 0.5 MW/m^3. This is an order of magnitude, or more, lower than the power density of a PWR fission reactor core. The ARC reactor is also much more complex, and will require very expensive maintenance operations every couple of years (manufacturing a new pressure vessel and remotely installing it, as the innards of the reactor will be too hot for hands-on access.)
So, how could this possibly be cost competitive with fission reactors, never mind the energy sources that are currently beating fission?
It's ironic that the ARC reactor is just demonstrating the fatal flaws with DT fusion reactors, flaws that were also pointed out at MIT by Lawrence Lidsky some 35 years ago. ARC is better than ITER, but that's damning with faint praise.
As you can see from some here, people just want to believe. Fusion is the power source of sci-fi, and they’re scared of fission. As with self-driving cars, people just imagine what it could be like and that’s enough for them. Never mind that decades of R&D on fission has yielded breakthroughs in safety and efficiency, and by the time a workable fusion design is possible far more advanced fission will be possible. People want the future to be now, so they believe their way into it. Scientists want funding for research, so they sex it up for the media and mass consumption.
The truth is that politics aside, we could be using fission today to solve the problems people want fusion to solve decades from now. Granted, if aneutronic fusion becomes possible (no time soon, even experimentally with a surplus of energy) that will be a miracle. DT fusion though, is only useful for research purposes.
Most people, including most people here don’t have a working understanding of nuclear physics or the requisite engineering of a power plant. When you don’t understand the hurdles, fusion seems kind of magical. If you’re desperate for advanced space flight, fusion seems kind of magical. Even more, no one has any negative experiences with fusion, while we’ve been literally burned by fission.
It’s hard to argue against a fantasy, and hoping for fusion also let’s people ignore the hard work of using fission. The politics feel intractable in the US, the waste is manageable, but scary. Fusion isn’t real yet in that sense, so like an online romance people can project a fantasy onto it.
To be fair some reponsabilites also come from poor performances of fission industrie leaders. In France the next generation fission power plant EPR was so much delayed that a lot of people are getting skeptical about this tech if not totally opposed for environmental reasons (trues or romanticized).
This is a shame as I globally agree with you that fission might have a transitional role to play in the mix needed to reduce our global warming impact. Consuming less non-renewables ressources being the first line of action anyway.
"Granted, if aneutronic fusion becomes possible (no time soon, even experimentally with a surplus of energy) that will be a miracle."
A group at Princeton has a concept for a FRC-based reactor burning D-3He that, through a combination of quite interesting tricks, reduces the fraction of power output in neutrons to as little as 0.5%. The design is also very small, with a power output of 1 MW. At this level of neutron output the reactor structure are lifetime components, with no replacement needed due to neutron damage. Power density is still a struggle, although the small size of the reactor helps there.
The downside (assuming the aggressive plasma physics doesn't disappoint) is where do you get the 3He.
At this point, my default vision of the future is neither fission nor fusion, but rather renewables and storage. The engineering and economic issues of these appear much more tractable. Simply extrapolating solar down its demonstrated experience curve puts the cost of PV electricity at $0.01/kWh or less when fully scaled out.
Sam Cohen’s Rotating Magnetic Field experiments have shown higher temperature and reasonably long-lived FRCs. His vision is steady operating, 3He systems, atleast at first targeting propulsion. As you dial up the Helium percentages, the neutron output goes down, though the required ion temperature goes up. Princeton Satellite Systems has several NASA programs looking at the propulsion applications.
The scheme involves significantly non-maxwellian ion distributions, so "temperature" isn't really appropriate. In particular, 3He ions get pumped to higher energy than D ions, which helps suppress DD fusion. They claim the scheme is consistent with Rider's limits on energy circulation in non-maxwellian plasmas.
No, "any low Z liquid" is not acceptable. It absolutely must contain 6Li to breed tritium. And it's quite likely that strong neutron absorbers would not be acceptable unless they also made tritium. The beryllium serves as a neutron multiplier -- the 5th neutron has the lowest binding energy of any neutron in a stable nucleus -- so without it the neutronics will suffer. DT reactor concepts already have issues breeding enough tritium to overcome inevitable losses.
Dismissing something as "an engineering problem" is typical of plasma physicists. Fission has only "engineering problems" and yet those are quite sufficient to render a technology uncompetitive.
I think the issue with using lead is not that it would have a lower neutron multiplication, but that it wouldn't moderate the neutrons as effectively. I think this would force the reactor to be larger to keep the neutron dose on the magnets within limits.
A process based on binding of Li ions to crown ethers could probably be developed for Li enrichment.
Whether this is likely or not, I hate articles like this. People refuse to give up even a little of their current lifestyles to make their lives sustainable and this article makes them think that is OK because technology is going to save them in the future.
> Prof Wilson was also cautious about the timeframe, saying that while the project was exciting he couldn’t see how it would achieve its goal of putting energy on the grid within 15 years.
So the startup seeking more funding is over promising as usual. As many others here have said, I'll get excited when someone actually achieves a net positive fusion burn and it's confirmed by a third party.
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Moreover, it's not clear if they will have a working reactor in less or more than 15 years, it's not clear if they are building a research reactor or a production reactor, it's not clear if they are going to collect the heat and use it to produce electricity, ...
Also, the article say that:
> A newly available superconducting material – a steel tape coated with a compound called yttrium-barium-copper oxide, or YBCO – has allowed scientists to produce smaller, more powerful magnets.
but if I understand correctly the new material is just a new type of superconductor wire that is more efficient than the current wires, it is not a superconductor magnet. If they have better wires, they can make better electromagnets, but it is confusing. Also is not clear if they have tested the new kind of magnets or it is just a theoretical application.
Also, 15 years is a lot of time, usually it means they don't have a clear idea of how to solve all the technical details. https://xkcd.com/678/
Both: https://www.youtube.com/watch?v=KkpqA8yG9T4&t=32m35s
This work is being done by the head of MIT's Nuclear Science department, in collaboration with most of the top grad students there. You can go look through all the publications that have resulted. They're going into great detail with practical engineering concerns, not just vague concept.
It's really disappointing and frustrating to me to see all the shallow dismissals here. The original article/press release didn't have much concrete information. But instead of making the reasonable assumption that some of the best people in the field actually know what they're talking about, and the article is poor, instead HN commenters are deciding their zero content, zero knowledge, shallow dismissals are more likely than what the experts are saying.
Nearly all the information about the ARC project is out there in the literature. If you don't want to read it that's fine, just try to have some awareness that you can't dismiss things without actually knowing what they are.
The most popular cases of overstatement are the improvement of the batteries life and the cure of cancer. but there are similar bad reporting in less popular fields.
In this case it's easy to decide. We can just wait until April 1st 2033 and see if there is a tokamak fusion reactor that can break even without creative accounting.
Even better, it's plasmaware.
http://csef.ru/en/nauka-i-obshchestvo/direction-topics/obzor...
It is mental and political/financial.
Achieving ubiquitous nuclear power is more like achieving ubiquitous electric cars than achieving ubiquitous flying cars. It’ll probably happen any decade now, vs maybe never.
Not a prototype, just a breakthrough. 50 million C isn't something to cough at.
However, I truly think it is wonderful that there seems to be a resurgence in the area of nuclear fusion. After Fukushima any project that had "nuclear" in its name was put on hold for political reasons and it's good to see that people don't have cold feet anymore.
Oh please... you have no clue what you are talking about.
But it's no panacea [1], there's still substantial radioactive waste produced and radiation hazards to those working near the reactor.
If you operate under the assumption that we should pursue nuclear energy, then this is great. But if you operate under the assumption that between solar wind and storage, we have everything we need without any radioactive waste or radiation hazards to workers, this is pretty uninteresting beyond academic purposes.
https://en.wikipedia.org/wiki/Fusion_power#Safety_and_the_en...
There's really no comparison; fusion is vastly cleaner and safer.
Has there ever been a activist group that stated loudly: "Yes, we pulled it off"- and then peacefully disolved, with the promise to reunite the day the defeated cause should return?
And yes, I vividly recall the only time in my tenure at MIT I saw a student light a cigarette. It was in 10-250, the person was sitting audience right side of the lecture hall, about 1/3 of the way back in the room. She did so once, on her first day of class as a transfer student.
So yes, change can happen, and be recognized, and the activists move on.
I just have a very negative counter-example here though: It was a radio-interview with a green-peace activist on ITER. And they would go to great length, to put the nuclear waste problem of fusion into the same category as the nuclear waste dilema of fission- although the fusion byproducts decay down to zero in 300 years- which is near nothing next to fission.
I really rooted for greenpeace once, but such intellectual dishonesty- with a fundamentalistic approach, expecting humanity to give up civilisation as we know it, instead of working with the humanity they got- lead to a deep distrust to everything they publish.
No one has ever recruited activists to a cause by announcing that things are getting better, and bearers of good news are often advised to keep their mouths shut lest they lull people into complacency. Also, a large swath of our intellectual culture is loath to admit that there could be anything good about civilization, modernity, and Western society.
My favourite example is this that in Australia we have no nuclear electricity generation large as a result of the good intentions of Greenpeace and The Wilderness Society, the later of which is largely responsible for there being no new hydro electric power stations in Australia after they were success in blocking the Franklin River dam project. That and there being pretty much no good sites left.
That realisation and my ensuing confusion resulted in me withdrawal from the whole debate with the hope that greater minds will work toward improving the situation.
If we have a path which involves zero radioactive waste, and zero biologically-active radioactive effluents, obviating the need for nuclear anything - why would we bother?
https://www.nextbigfuture.com/2008/03/deaths-per-twh-for-all...
Deaths from the Tsunami: 15895
Deaths from radiation: 0
Note that the deaths include those from technology that failed due to the Tsunami.
And note that by "little known fact", I mean "fact that is so little known that people 'know' the opposite of what is actually true"
Anything requiring the immediate long-term evacuation of an entire prefecture in a failure mode is obviously unsafe.
Lies, damn lies, and statistics.
You are willfully ignoring the fact that all forms of energy pose hazards, and that the hazards posed by other forms of energy are vastly higher, usually several orders of magnitude.
And you are reacting emotionally, "oh my god, nuclear horrible bad", rather than looking at the numbers rationally. If you look at the numbers, nuclear energy is incredibly, almost comically safer than any other form of power, including rooftop solar. Yet the public perception is exactly the opposite.
The evacuation of the entire prefecture was almost certainly an overreaction, due to exactly the incredible over-weighing of the dangers of radiation. Yes, radiation is dangerous, but not that dangerous, and the main negative health effects (and deaths) were from the evacuation!
Look at the WHO reports on Chernobyl. They published a report every ten years after the accident, and in each report they dramatically lowered their estimates of deaths due to radiation effects, and in each report the negative health effects of the evacuation became more clear.
"The only thing we have to fear is fear itself". -- FDR. With nuclear power, the fear of radiation is currently a much greater threat than the actual radiation itself.
“Carbon-free fusion power could be ‘on the grid in 15 years’”
And then later:
“Prof Wilson was also cautious about the timeframe, saying that while the project was exciting he couldn’t see how it would achieve its goal of putting energy on the grid within 15 years.”
There must be a curve, where it can be estimated at what cost-point fission and solar are out- and for example growing ressources in vats becomes cheaper then farming/ chopping down natural grown wood.
What other "uneconomic" endavours become feasible with fusion at what price?
Salt water desalination - at some point pumping salt water (possibly long distances) to desalination plants for agricultural and domestic use becomes feasible.
Space programs - once oil is disrupted as an energy source for the masses it will be cheaper to push things into orbit.
> once oil is disrupted as an energy source for the masses
I'm confused, what else do the masses use oil for? If I'm not mistaken the production of fuel for transportation is the lions share of oil use.
But regardless, how does that help us get things to orbit?
At risk or repeating myself, what does any of this have to do with getting to orbit?
This article[1] claims Falcon 9 launch list price is $61.2 million and "Musk said the fuel used on a Falcon 9 is between $200,000 and $300,000."
So the fuel cost is 0.5% of the launch price.
It could be argued that if we stop using oil for transportation the price of oil derived kerosene and methane could go up as production scales down and fewer refineries sell in to the market.
1. http://spacenews.com/spacexs-reusable-falcon-9-what-are-the-...
Let's combat global warming by producing even more heat, converting 40% of it to electricity.
All the wattage produced by humanity is utterly insignificant in the face of the energy we receive from the sun. It will still be insignificant if we double it.
(We receive about 2 × 10^18 watt hours per day from the sun at the ground. Daily human energy production is about 5 × 10^15 watt hours.)
Or if we take "5% of an extra sun" as the problematic power output, it will take only 150 years.
(Now consider that in the golden age of oil before the oil shocks in the seventies, oil consumption was growing more like 8% per year.)
At that time, per capita energy use in the US was growing by 3% per year while population would grow by 1.5% per year. Today, per capita energy consumption in the United States is falling, and the population is growing more slowly. The story is much the same elsewhere. Even China has leveled off in per capita energy consumption. India's is still growing, but it will take many years considering their baseline of 1/10 of the United States per capita before they're the biggest problem, and I guess they'll probably turn that trend around before they actually get to that point.
Is there a reason everyone in this thread is saying "semiconductor" instead of 'superconductor'?
The closest parallel we have is nuclear reactors. Navy Nuclear submarines are probably the most prevalent safe small reactors (US submarine reactors not K19) and they have significant lifespans extending across multiple decades. (source: passed my navy nuclear engineer exam in a past career) The resulting embrittled can/containment does need to be handled safely, but this is a capital depreciation that can be modeled and planned for.
That said nuclear proliferation from tritium is a lot less of a risk than from uranium. Anyone can put together a nuclear event with sufficient enriched uranium, pinching tritium to fuse using a fission event, well it's a significant technical hurdle.
https://youtu.be/KkpqA8yG9T4
What damage will it do while it's cooling off for whatever period of time.
TL;DR Boom lots of dead people in the containment structure, expensive cleanup, but nothing like a fission disaster. It would be an uninspiring explosion, but it would be dirty.
Or for better context: research facilities today regularly lose plasma containment. It's why we don't have practical fusion reactors, but they're already at the plasma densities we would run at (which is an order of magnitude or so better then the Sun achieves).
Densities are extremely low, so you only have a few grams of material in the reactor, even at large volumes anticipated for a commercial design.
Furthermore, the reaction is extremely finicky, as demonstrated by what an incredibly hard time we are having creating and more importantly sustaining it. Any deviation from the ideal and it just goes out. So no runaway chain reactions.
https://en.wikipedia.org/wiki/Fusion_power#Accident_potentia...
Basically natural gas explosion, with a radioactive metal torus.
I think I remember hearing something like that anyone more than 50 feet away would be completely unaffected (but don't quote me on that).
The material science behind high temperature semiconductors has undergone radical changes in recent years. The techniques being used are largely well understood science and the downsides of previous approaches like ITER are explicitly avoided. There has been a visible explosion of commercial activity in recent years.
People bander around the "always 20 years away" moniker as if we should put today's estimates on the same grounds as the guesses from those early 1970s projects that were never even properly funded. People were not screaming "20 years more" at the turn of the century.
You don't get to discount something as potentially groundbreaking as this just because it's taken a little while to get here. Either put up or shut up. I would love to hear genuine substantive conversations here, if people were willing to have them.
So when researchers say, "this supporting piece of the puzzle has gotten much easier," as it is with the new magnets described in the article, that's actually a good time to listen since it might be the tipping point. Theory developments or experimental observations are exciting stories to read about but often have less imminent bearing on whether you're going to see it impact your life.
I think economics offers a great perspective to subscribe to, but haven't found much opportunity to learn it. Most "economics" podcasts are really just business-focused and describe modern events with little insight into the economics behind it.
Specific areas after that...
"Brilliant" by Brox on the history of lighting.
"Salt" by Kurlansky.
"The Master Switch" by Wu on telecoms and broadcasting.
"Ascent of Money" by Ferguson has some critics, but it's got some great historical anecdotes on the history of financial tools, like fractional reserves and insurance, weirdly captivating.
Those are all economic history... If you really want a pop intro to econ principles, maybe Planet Money? Pretty much everyone should listen to Planet Money anyway, it's just great radio.
They try so desperately to make the topics sound fun/accessible that it ends up sounding like a disingenuous forced comedic act rather than a natural, education conversation with the guests...I guess I'm not the target audience for this.
But I love the book recommendations. I plan to read that Kessler book tonight.
I think he's most known for his work in the role of institutions (which I think helps elucidate the "economic factors that come together" part of your curiosity): https://en.wikipedia.org/wiki/Douglass_North#Institutions https://en.wikipedia.org/wiki/New_institutional_economics
It's common to point to technological advancements such as steam which gave way to the Industrial Revolution, that Britain had coal etc. And that's definitely important because steam powered factories which was a major change from household/hand/craft businesses.
In truth there were many contributing factors. But why Britain? Why was this the place where all these inventions were being made? Some historians get very creative in additional reasons for how this era came to be. Rosen makes the really interesting claim that it was the idea of intellectual property that triggered all the inventing-- that man could own an idea and make money from it!
-Sputtering of shielding and every other part of the reactor from fast neutrons. If your reactor is becoming brittle as it’s in operation, and requires constant maintenance, it won’t be operating enough to be cost effective.
-Breeding blankets. If we’re not breeding tritium in the blanket (and no one has been able to sustain a reaction that way yet) then we’re just using fission a lot. Expense becomes an issue, as does radiological issues.
-The plasma diverter is very much an unsolved problem. I can get into more detail here, but in short this is the part of the reactor that “skims” some of the hot plasma off to do the work. The dynamics of very hot, magnetically constrained plasmas still escapes us, and when you throw a rock into that stream, the complexity increases. Current divertes wouldn’t last a day in an operating plant. Disassembling your whole plant every day and reassembling it is a non-starter.
-Containment of plasma at sufficient energies is still something measured in seconds, or fractions of seconds. The usual metaphor is trying to uniformly squeeze a balloon; it will just “squirt” out. For s research reactor a second or two of fusion is an achievement. For power generation it’s nothing.
-Neutron activation of otherwise inert materials means you’re going to have serious radioactive waste. It’s unclear just how dirty D-T fusion would be from soup to nuts, but “pretty dirty” seems like a good bet.
-Tritium penetration.
-Most of the energy produced is in the form of neutrons, and we don’t know how to use that as a source of power. Those neutrons, in addition to destroying the reactor itself and activating materials, represent a loss.
-What we really need is aneutronic fusion through alternative cycles to D-T, like p-p, but that’s a much hotter plasma and no one has a clue how to make it work yet.
-Coolant for a constantly running reactor is a boring, but unsolved problem.
There’s more, but these are the ones most poeple on HN probably are aware of when they dismiss this article.
Some further reading https://thebulletin.org/fusion-reactors-not-what-they’re-cra...
Fusion is advertised as a clean power-generation technology, but it will, in general, have its own radioactive-waste disposal problems.
@csallen: Be willing to actually dispose of it. We need to commit the money and political will to set up a single disposal site. Right now it’s a NIMBY nightmare so we get the worst outcome.
1T of thorium produces the same amount of energy as 35T of uranium or 4166000T of coal. 83% of the waste products are inert, and 17% require only 300 years to reach background levels of radiation. Much safer than uranium cycle too.
This technology is very promising IMO, though given the general attitude people have towards nuclear, it's not surprising it is underdeveloped, more research is needed.
[1] https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...
To claim otherwise is, as you would have it, lying.
More importantly, both are solved issues from a purely technical standpoint, it’s just that everyone wants someone else to deal with it. As a bonus, we can actually use fission to produce energy, right now. There’s no issue of, “it will be great when...” grid storage is solved along with intermittency for renewables. There’s no, “it will be great when...” fusion is producing energy rather than heavily parasitizing from the grid. There’s no waiting until we’re completely screwed by climate change effects.
- The inner wall of the reactor is 3D-printed and replaced annually. This is easy because they've found they can make joints in the superconducting tape that add very little resistance, allowing them to include hinges letting them open the reactor.
- Surrounding the inner wall is FLiBe molten salt. It's heated by the neutron radiation, acts as coolant for the thermal cycle, and as the breeding blanket (each high-energy neutron releasing two neutrons from impact with beryllium, providing plenty of neutrons for breeding tritium from lithium). Having a liquid blanket makes tritium harvesting easier.
- Stronger magnetic fields damp down plasma instabilities, making containment easier. For years MIT has been running the Alcator C-Mod, which has more powerful fields than any other tokamak in the world, so they have some direct experience here.
- The neutron-activated wastes would only need containment for several decades.
(I don't know anything about the diverter, and I'm interested if you want to get into more detail.)
The MIT folks argue that we understand tokamak plasmas much better than any other configuration, and have gotten far closer to breakeven than alternative designs, so that's where we should focus.
However, there are some projects working on aneutronic fusion, mainly with p-B11. The biggest project is Tri Alpha, with $500M invested. They've achieved stable plasma at 10M degrees, and are about to start testing a new reactor which should reach 100M degrees. If the plasma continues working as the expect, they think it's a straightforward path to a production reactor; of course there could be surprises.
Another approach is laser fusion with petawatt picosecond lasers. We're not far off from having a laser with the specs to attempt this, and these lasers improve by a factor of ten every three years.
Helion, funded by YCombinator, is attempting a hybrid D-D/D-He3 reaction. (The output of D-D is half He3, and half tritium which decays to He3 with a 12-year half-life.) They say the hybrid reaction would release only 6% of its energy as neutron radiation. I don't know how it's going though.
"People were not screaming "20 years more" at the turn of the century." - which century? I went to school in Oxfordshire, UK (later half of the 1980s) and studied physics to A level and went on a field trip or two to the local nuclear fusion project.
I clearly remember being told by everyone there how progress was measured. It seemed to boil down to a chart with time on the x axis and factors away from sustainable fusion on y. This may have been a "lies to children". The chart looked like an exponential decay with a rather wobbly tail starting in the late or so 1970s back then.
There is a good reason for the 20/25/50 years meme. It's the best model we have had for progress for a very long time. I will be ecstatic to get my 'leccy from nuclear fusion in my life time and unimpressed if my grand daughter is still waiting.
“Prof Wilson was also cautious about the timeframe, saying that while the project was exciting he couldn’t see how it would achieve its goal of putting energy on the grid within 15 years.”
That’s deep enough for me.
but in 16 years tho... maybe
The just-over-the-horizon timeframe normally cited is 30 years, but the MIT team believe they can halve this by using new superconducting materials to produce ultra-powerful magnets, one of the main components of a fusion reactor.
Halving the just-over-the-horizon number isn't progress. It's marketing.
Well I think people have great reason to be skeptical. I hear "Fusion is around the corner" at least once a year. Usually it is by smaller companies but every once in awhile it is the bigger ones.
So let's look at the big one. In late 2014 LOCKHEED MARTIN announced that their compact fusion device would be demonstrated in a few years and have an operational prototype by 2019 [1]. Even Scott Manley has the top comment on that video as ""high risk" = we don't actually have it working, but there's a chance we could." Even in the video suggests it wouldn't get onto the grid by 2034 (20 years from their announcement).
So maybe you're right, it isn't 20 years away, only 16. Which serendipitously lines up with the 15 years claimed in the FIRST SENTENCE. Which is then given many asterisks at the end and doubted by the lead scientist.
TLDR: People band around "it is 20 years away" because experts are still saying "it is 20 years away." (including this article)
[1] https://www.youtube.com/watch?v=UlYClniDFkM
End note: That being said, I don't want to downplay the improvements. We are SIGNIFICANTLY closer than we were in the 80's/90's. Several of the major problems have been improved upon. And I do think I will see fusion on the grid in my lifetime. More so, I really think it will happen within 20-30 years.
Groundbreaking is usually overused. How many genuinely groundbreaking things emerge from press releases as opposed to deep investment by state backed actors? Seriously, Edison (for instance) was a wizard at commercial applications but frankly useless as a scientist.
I call Leo Szilard groundbreaking. He really did have a flash of insight.
Crispr didn't just happen. It took a shedload of prior work. FMRI is groundbreaking except they're all walking back from the pop sci stories into more fundamental tests.
So is this stuff really worth substantial conversation? Who is going to invest in chatter here? MIT and Lockheed won't, for obvious reasons. And I doubt jet or iter scientists will, for other obvious reasons. Who is left who would meet your criteria?
In this case, we start with a headline that the most transformative technology since combustion is just around the corner.
The basis for that claim? That they are going to create an experimental reactor using new high-temp superconductors.
Well ok, great. But this is just a lame press release about how somebody HOPES it will work. It's not even a technical argument: it's basically a business argument, using currently available technology. Just the nuclear power version of the "suits" article that comes around every year, and that PG called out in 2005 [1]
So what, exactly, can a person substantively say against /this/ piece? I would argue: practically nothing. The best points raised by others relate to fusion in general, which we could have had without this submarine PR piece.
1. http://www.paulgraham.com/submarine.html
I'm a layman when it comes to these things, but does that mean they have improved tokamak's or will future nuclear fusion reactors more look like the stellarator used in Wendelstein 7-X for example?
We got to talking. He assured me they were getting closer and it was only a matter of time (read: money). I'm not a politician or an investor, etc. so he had no motivation to blow smoke up my arse.
Less than a week later there was this:
https://www.wired.co.uk/article/china-fusion-breakthrough
100+ seconds is not a lot of time. But if you double that every few weeks then it __is__ only a matter of time.
I'm sure once a proven breakthrough occurs, money will begin to flood in. The potential is massive.
my beef with fusion is that people think that if we 'discover' how to pull off net positive fusion that it will suddenly result in limitless energy as opposed to a slow and centuries long process to make it profiteable.
sustainably profitable fusion is NOT likely to explode in usefulness the same way nuclear fission did.
we might discover how to sustain net positive fusion, but scaling it up in any single reactor might prove problematic and fusion may wind up being a very hair problem to improve to high levels of profitability and energy production for a long long time after fusion sustainability is 'discovered'.
from a purely economic perspective, fusion and fission have zero reason to exist for economics.
fission makes sense for fuel density for powering weaponized systems in space and at sea and remote locations.
fusion would be filling the same precise needs at best, otherwise, in a world where there is limited resources to invest in R&D for global energy research for powering cities and civilizations commercial and residential energy needs, our money should be going into making our consumption more efficient, and our existing sources better.
solar, wind, natural gas, hydroelectric, coal and other existing sources should all be made more efficient. we simply don't need to invest in 'new' energy sources like fusion. they are redundant from an economic perspective.
and energy transmission, distribution and STOREAGE all need massive amounts of new R&D investment.
that is where the economics make most sense.
As far as I understand fusion is at a point where we know almost 100% it can be done but there is a long list of hairy problems to solve. Working on these is money well spent in my view.
The design of the ARC reactor in the 2014 arxiv paper produced 500 MW(th) fusion power. The FLiBe bath contained some 90 tons of beryllium. The annual world production of Be is just 220 tons. If the world's entire estimate resource of mineable Be (100,000 tonnes, according to USGS) were used to make ARC reactors, they might supply 1% of the world's primary energy demand.
The FLiBe also contains about 1/4 the 6Li produced by the entire US hydrogen bomb program. The facility that enriched that lithium used 10,000 tons of mercury and is an environmental problem even to this day because of leaks. That process is also now illegal in the US due to this pollution, and there is no facility in the world that could make that much 6Li.
Perhaps those problems could be worked around, but there's a deeper issue. The power density of the ARC reactor is around 0.5 MW/m^3. This is an order of magnitude, or more, lower than the power density of a PWR fission reactor core. The ARC reactor is also much more complex, and will require very expensive maintenance operations every couple of years (manufacturing a new pressure vessel and remotely installing it, as the innards of the reactor will be too hot for hands-on access.)
So, how could this possibly be cost competitive with fission reactors, never mind the energy sources that are currently beating fission?
It's ironic that the ARC reactor is just demonstrating the fatal flaws with DT fusion reactors, flaws that were also pointed out at MIT by Lawrence Lidsky some 35 years ago. ARC is better than ITER, but that's damning with faint praise.
The truth is that politics aside, we could be using fission today to solve the problems people want fusion to solve decades from now. Granted, if aneutronic fusion becomes possible (no time soon, even experimentally with a surplus of energy) that will be a miracle. DT fusion though, is only useful for research purposes.
Most people, including most people here don’t have a working understanding of nuclear physics or the requisite engineering of a power plant. When you don’t understand the hurdles, fusion seems kind of magical. If you’re desperate for advanced space flight, fusion seems kind of magical. Even more, no one has any negative experiences with fusion, while we’ve been literally burned by fission.
It’s hard to argue against a fantasy, and hoping for fusion also let’s people ignore the hard work of using fission. The politics feel intractable in the US, the waste is manageable, but scary. Fusion isn’t real yet in that sense, so like an online romance people can project a fantasy onto it.
This is a shame as I globally agree with you that fission might have a transitional role to play in the mix needed to reduce our global warming impact. Consuming less non-renewables ressources being the first line of action anyway.
A group at Princeton has a concept for a FRC-based reactor burning D-3He that, through a combination of quite interesting tricks, reduces the fraction of power output in neutrons to as little as 0.5%. The design is also very small, with a power output of 1 MW. At this level of neutron output the reactor structure are lifetime components, with no replacement needed due to neutron damage. Power density is still a struggle, although the small size of the reactor helps there.
The downside (assuming the aggressive plasma physics doesn't disappoint) is where do you get the 3He.
At this point, my default vision of the future is neither fission nor fusion, but rather renewables and storage. The engineering and economic issues of these appear much more tractable. Simply extrapolating solar down its demonstrated experience curve puts the cost of PV electricity at $0.01/kWh or less when fully scaled out.
The scheme involves significantly non-maxwellian ion distributions, so "temperature" isn't really appropriate. In particular, 3He ions get pumped to higher energy than D ions, which helps suppress DD fusion. They claim the scheme is consistent with Rider's limits on energy circulation in non-maxwellian plasmas.
The small company proposing using this for a notional Pluto orbiter:
http://www.psatellite.com/
Primary patent for the reactor:
http://www.freepatentsonline.com/9767925.html
https://youtu.be/KkpqA8yG9T4
Sounds like the only thing standing in the way is prototype funding.
https://youtu.be/KkpqA8yG9T4
They also discuss advancements in internal chamber maintenance access. That side is really an engineering problem.
Dismissing something as "an engineering problem" is typical of plasma physicists. Fission has only "engineering problems" and yet those are quite sufficient to render a technology uncompetitive.
actual limit, or economically feasible? If the latter, that may change
I think lead does the same thing for neutronics...somebody educated me once on why it's not a viable option but I forget the details.
Maybe somebody can find a better way to purify 6Li.
A process based on binding of Li ions to crown ethers could probably be developed for Li enrichment.
So the startup seeking more funding is over promising as usual. As many others here have said, I'll get excited when someone actually achieves a net positive fusion burn and it's confirmed by a third party.
Stopped reading.