Revamped German stellarator should run longer, hotter and compete with tokamaks
science.org
science.org
That hasn't mattered much thus far because Q is so far off, and investors pour money in regardless.
Structural material that can stand up to the neutron bombardment has not been identified; no one has worked on it in decades. No one knows how to breed enough tritium to fuel it, or how to extract it from the shielding ("blanket") fast enough to be useful, if indeed they did manage to breed some.
Current estimate is that working fusion is 40 years off and receding. People, and particularly startup companies, insisting otherwise are simply lying through their teeth. Securities fraud is poorly enforced.
Q is thus not very important, except maybe for getting more money.
So, there is nothing here to get excited about unless you are very keen on plasma fluid dynamics. Plasma fluid dynamics is probably the hardest kind of physics, so anybody who can do it deserves respect. It is a shame we can't find much for them to do besides fool with fusion and work on actually-useful ion propulsion.
And it would face the same showstoppingly bad volumetric power density as tokamaks, because of limits on that energy flow through the surface of the reactor.
I do think it is worth persevering though. The future of energy is Solar/Wind but Fusion should not be ignored. It is one of Nature's fundamental processes. Mastering fusion could turn out to be useful in ways we cannot possibly fathom at the moment right now.
But yes, there is a potential for a lot of space applications and other things we haven't thought of yet.
Technically, container ships are enormous and can use ballast water for shielding. I can't judge the ecobomics ofcourse
Large container ships burn through 16 tons of bunker oil per hour, and each journey can last up to 3 weeks - any idea what size of battery such a ship would need? I have no clue how to calculate that), but I'm guessing it would be completely impractical, even if we made huge strides in battery energy density.
I remember reading that they would have more limited range and lower top speeds, but that this might not be as much of a problem as it seems because the current routes are built around large container + long haul but that's not necessarily required (for all shipping at least).
[1] eg. https://maritime-executive.com/editorials/could-battery-powe...
There are hundreds of nuclear powered ships already - submarines, Icebreakers, carriers, etc.
Aren't they all operated by militaries though? So if a conspiracy of crew members tries to steal some enriched fuel or fission products, it is legal to just shoot them or throw them in jail for decade for trying.
On board the ship itself, all the nuclear material is inside a running reactor, any would-be criminal would be dead before you could shoot them
Russian nuclear icebreakers are civilian ships, and people working at normal nuclear power stations are civilians too.
It is actually only relevant what happens in the part of the chain that handles nuclear fuel - thats the shipyard plus processing of spent fuel. But again, we do that for powerplants already.
I'm hoping that some of the battery technology currently under development (such as flow batteries, or aluminium-sulphur batteries) can trade space and weight for increased total capacity. A good battery for grid storage would probably work well for a container ship.
Here's[2] a company offering a 1MWh battery in a standard 20ft container. EverGiven[3] carries ~20,000 standard containers. So, five EverGivens?
[1] https://www.traditionaloven.com/tutorials/energy/convert-ton...
[2] https://www.geebattery.com/battery/1mw-lithium-battery-energ... (The first one I found, without looking for the smallest).
- The energy density of LiIon batteries (or molten salt, or liquidy nitrogen etc) is roughly 100x smaller than that of gasoline/diesel/bunker fuel in weight terms and 40x smaller in volume terms
- The efficiency of electric motors is roughly 2x that of large diesel engines
So the amount of batteries needed for the same performance is 50x larger in weight and 20x larger in volume than the oil it carries (which for a big container ship is 6,000-10,000 tons I think). Which would be impractical.
In practice, synfuels would be better than either for ships on Earth.
Also, if it makes a difference, I didn't mean we'd be bolting a first gen tokamak to a container ship; I meant, much later down the line, if we were able to miniaturise (similar to how we have nuclear powered subs and ice breakers).
Fusion is a meme technology. People just have this assumption that's it's valuable, without having rationally arrived at that conclusion (which, when you examine it in detail, is very difficult to justify.) I suspect this was because it started back in the 1950s when consent was easier to manufacture and nuclear was being pushed. Fission lost that glamour with most people, but fusion somehow has retained it.
With all due respect, it seems ridiculous to me that fusion is a "meme technology" - aside from money, are all those many thousands of scientists really working on a technology they know can't work?
Look at Tri-Alpha. The people involved with that (Rostoker, Binderbauer and Monkhorst) were told 23 years ago that their colliding beam H-11B concept didn't work, for multiple reasons. Yet look at how much money they raised.
https://www.researchgate.net/publication/235032059_Comments_...
None of these startup companies will ever produce a lone kWh of commercial power. But they will very diligently spend every dollar they are handed by VCs. The VC brokers know the score, but the money spent goes for equipment from quite profitable companies. It is not their money, and there seems to be plenty of it.
Like, whether or not fusion itself is a "meme," the idea that we spend obscene amounts of money on it is absolutely a meme with no real backing in reality.
The appeal of fusion is really more about getting out of worrying so much about meltdowns and weapon proliferation, and that there is potential for much higher overall energy output if we can figure it out.
That last bit is why, imo, we should be investing in it now even though it won't really help us reach net zero carbon "in time". If we want to reverse our carbon impact, if and when we get to net zero, we're going to need immense amounts of energy to do it.
I will say I do think money has been spent unwisely on fusion, particularly on approaches that have very little chance of success, with programmatic dysfunction that even fusion advocates have noted with anger. Chance of success does have to enter into the evaluation of whether funding is wise, or else one could argue for spending on perpetual motion machines.
But it is absolutely a common misconception that fusion is very well funded when, given the challenges involved, it is funded quite poorly. If it was well funded, ITER might have been finished 20 years ago.
That said I think the results would have been disappointing, it doesn't really seem like material science was there yet and it's not clear more money thrown at it then would have gotten us there.
Imo I think even if you think it's a boondoggle it'd be better to fund it well (much better than we are) now and find out than drag this slow march of wasted money on old designs and ideas out forever. The ITER funding should have probably gone to something more like milestone awards and letting a bunch of paths proliferate.
We can all think of numerous projects going unfunded that would have much higher chances of success, and much greater positive impact. But we have a research institution whose only possible recommendation is to continue giving it money, indefinitely.
We see the same dynamic in Alzheimer Syndrome research, where almost all the research money goes to people still fooling with amyloids and tau tangles. The people who control publication, funding, and hiring are people who would have nothing to do if funding for amyloid work stopped. So, they continue funding amyloid work long after it was recognized as a dead end. They have bred up mice that get dementia, and literally everything they do is about the mice.
This is somewhat different from the current crewed spaceflight program in the US, where the absurdly expensive SLS rocket is mandated to be used because senators have constituents in their districts depending on income from building them, useless as they are. In this case NASA would dearly love to abandon SLS, but is required by law to try to launch them. The best they can do is delay launches. Anytime the shoot one, they have to spend $billions building another one.
I can think of far more things getting funded that are either even less likely to succeed or likely to succeed and, in so doing, will cause harm and death to many people. There are so many things we're spending so much money on that do nothing but harm it's absurd to laser focus on something you consider merely pointless as a Boogeyman.
No, we can, in multiple ways. Batteries of many different flavors, pumped hydro, storing as thermal energy (via resistive heaters or heat pump cycles), hydrogen (electrolyzers have crashed in price) and other e-fuels. Costs of these are declining rapidly as demand picks up and the scent of trillion dollar markets entices a wide range of enterprises and investors. Storage has not been much of a thing before because we were still burning fossil fuels and could just turn those up and down instead. But that doesn't mean storage wouldn't work.
In Denmark now e-fuels will be much cheaper than the fossil fuels (well, except maybe coal) you are now using. You're temporarily stuck in a rough spot right now, but the way out is via renewables + storage, and you'll be saving money doing it.
You are claiming that e-fuel costs are declining rapidly, but you forget to mention that there's no meaningful market anywhere on earth meaning we don't really have any experience with it and don't know how much it'll cost and how it will work exactly(will it be hydrogen, ammonia etc.) it's simply not a solved problem and there's no infrastructure to support it. It might make sense in the future to use e-fuels together with wind but what we're trying to do here in Denmark is to use wind and solar for the grid which sucks. Electricity prices fluctuates wildly at the mercy of the weather gods. Thermal energy storage is also still experimental and hydro only works in very very specific locations where it's already utilized. If we where to build new hydro we would destroy even bigger ecosystems than we already have.
Edit: I'm not even necessarily arguing against wind and solar, I'm just off the opinion that it makes much more sense to build out nuclear to support the grid first giving everyone cheap and stable electricity as well as providing district heating where it's already built out.
Doing Step 1 alone is very difficult so the've postponed Step 2 to the future. I may be wrong though.
Much of that work can and is researched in parallel, but there will be inevitable integration hell that has a burning fusion reactor core as a prerequisite.
https://cpb-us-w2.wpmucdn.com/research.seas.ucla.edu/dist/d/...
Globally we are definitely spending $10B+ per year.
The promise of profit often helps enables all the previous steps.
Long term research can lead to eventual profit, sometimes many decades later. Sometimes it does not.
Long term research is speculative investment -- high risk for high reward.
However, at the stage fusion research is, the main problem is figuring how to create a device to keep the plasma fluid stable for long periods of time. As far as I know, none of the existing prototypes aims to be a functional electricity generator.
But the wall would be heated by the neutrons hammering it. Nobody has identified a material to make this wall out of. It has not even been worked on in decades.
“The helium nucleus carries an electric charge which will be subject to the magnetic fields of the tokamak and remain confined within the plasma, contributing to its continued heating. However, approximately 80 percent of the energy produced is carried away from the plasma by the neutron which has no electrical charge and is therefore unaffected by magnetic fields. The neutrons will be absorbed by the surrounding walls of the tokamak, where their kinetic energy will be transferred to the walls as heat.
In ITER, this heat will be captured by cooling water circulating in the vessel walls and eventually dispersed through cooling towers. In the type of fusion power plant envisaged for the second half of this century, the heat will be used to produce steam and—by way of turbines and alternators—electricity.”
That’s about ITER, but the two devices do not differ in this.
I.e. instead of letting the steam escape into the air after going through a turbine using some mechanism to passively cool/condense it "somehow", reusing _all_ coolant water, only having closed loop(s) (the "inner" cooling loop is often closed anyway for various reasons transferring the heat to an outer loop before its used for anything).
I think in a stellarator you will need divertors to remove the fusion products because of the continuous operation.
How to keep the blanket from quickly degrading and becoming nuclear waste seems to be an open problem (not too different from what goes on in fission reactors though)
Not really. Most reactors plan to also use the neutrons to breed the tritium fuel for the reactor, so the blanket would consist of liquid metallic lithium. The only products from neutrons reacting with lithium nucleii (either 6 or 7) are He-4 and tritium.
The open problem is how to safely maintain the reactor-facing wall of the lithium blanket. It gets bombarded by a lot of neutrons, yet needs to contain the hot lithium. It helps that the lithium can be unpressurized, but it's still a problem, because molten metallic lithium is not fun to have leak into anywhere.
The plan of the ARC guys appears to be to design the reactor so that the lithium vessel is easy to remove and swap for a new one, and just use steel for the vessel. The downside of this is that it's going to result in a lot of low-activity waste -- actually probably quite a bit more than what fission plants produce. There are other approaches, including using a material that doesn't really get activated by neutrons, and which is maintained above it's annealing temperature so embrittlement caused by dislocations is repaired as it happens. The downside of this is that materials above their annealing temperatures can be kind of soft.
https://www.thoughtco.com/lithium-isotopes-radioactive-decay...
Making the blanket out of molten metal would be a problem anyway because it is conductive, and you are trying to control a magnetic field inside the reactor chamber with coils around the outside of the blanket. Varying magnetic fields would set up eddy currents in the metal that would oppose changes to the field. So you probably need a diamagnetic insulating compound of lithium. What to bind to the lithium is a tricky question, because you don't want it stealing neutrons you need to breed tritium from, and getting radioactivated besides.
Under ideal conditions, if you had pure 6Li and 7Li, a neutron it stops would end up producing more than one tritium nucleus. The problem is that you have a great deal of other stuff that will steal neutrons, including pipes.
You could make the blanket with LiD, lithium deuteride, and any neutrons the deuterium picked up would make a tritium. But lithium deuteride melts up around 700C, which is hotter than most people like to imagine operating reactors. Worse, you cannot chemically distinguish the deuterium from the tritium, when you try to extract it.
There is a separate problem of extracting any bred tritium, in parts-per-billion concentration, out of the blanket.
A thermonuclear test yielded much, much higher energy, due to unexpected lithium 7 reactions.
Furthermore, nobody knows how to get enough tritium bred in it in the first place. You need for each neutron captured to breed more than one tritium nucleus, to make up for the fraction that fails to breed any. A fusion reactor with no fuel is a remarkably expensive doorstop.
I am guessing that the water used to cool the interior walls will get hot in the process...
The complex design of a Stellerator's magnectic coils essentially avoid the need for a transformer as it is being used in a Tokamak. The transformer is the reason why a Tokamak can only be operated in pulsed mode. However, there is ongoing research to achieve continuous operations e.g. by means of high-frequency waves.
Much better explanation here: https://www.ipp.mpg.de/14869/tokamak
https://www.researchgate.net/figure/Port-allocation-of-the-W...
There's a chapter on W7-X diagnostics in this DOI (check sci-hub). It doesn't include a comprehensive list of diagnostics or their port assignments, but it was the best I found at a glance.
10.1007/978-1-4613-0369-5_76
Over tokamaks, the other main technology that scientists are exploring for fusion power, stellarators require less injected power to sustain the plasma, have greater design flexibility, and allow for simplification of some aspects of plasma control.
However, these benefits come at the cost of increased complexity, especially for the magnetic field coils.
I've been quoting the proverb for a long time. Thank you for the quote, I feel it says basically the same thing but I appreciate the different wording and that it is attributed to Plato.
- Forgot where I heard that. It may have been a comedian.
I admire your optimism. I'd say half a century, if things go well, but I'm not convinced fusion will ever be economically feasible.
There's this [1] famous graph comparing US research spending into Fusion, compared to 1976 predictions how long it would take with different budgets. According to that, the US funded fusion below the "not enough to ever get it done" budget. With that in mind, we have come remarkably far.
1: https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...
Also, I think you have causality reversed. Fusion isn't remote because of lack of funding; rather, funding was low because there weren't stakeholders pushing for it, and that was because the stakeholders didn't see any value coming from it. For example, all the reactor designs utilities had been presented with were not things they had any interest in building, they were too large, complex, and expensive.
(I know I still owe you a detailed response on the thermo thing.)
https://assets.publishing.service.gov.uk/government/uploads/...
Early designs for ITER where for a larger device that would have actually produced electricity though not cheaply enough to be economically viable, but it got scaled way down.
HTSCs weren't usable when it was designed, and have only just become usable in the last 5 years or so but they are a fundamentally different material. You don't just drop them into a large, incredibly complex machine that depends on it's integrated magnetic containment system: you are functionally building a new device.
If you can ITER, then you don't get a refund on spent dollars. You get a loss. And then you get to start another 30 year project to maybe build a new vacuum vessel, which you have to do because you still haven't actually tested plasma stability.
"But but MIT skunkworks!"...yeah. It's still going along, and they haven't suddenly churned out a functioning reactor based on HTSCs because oh look, whatever the advantages they're a new material with different properties, manufacturing and handling behaviors all of which need to be developed, measured and inspected before you can use them effectively in a fusion device. If they look good then great: they can be used to make DEMO, the ITER-successor commercial powerplant prototype, cheaper and more powerful.
Not on Earth. But put a good enough fusion reactor on a rocket, and you can reach neighboring stars in 3 or 4 decades instead of the 15 one would expect for fission. (Of course, nobody is even sure reactors can get that good, but it does look possible.)
I think nuclear propulsion is going to be the biggest beneficiary of higher mass-to-orbit-for-a-reasonable-price advances.
There are a huge number of propulsion technologies that are physically possible but too heavy and/or dangerous for near-Earth use.
Cheaper lift (to bootstrap) + more ongoing destinations and transit work (to drive) + outside of Earth orbit (to alleviate safety concerns) = rapid progress
The proposed fuel is even worse as AM242 has a half life of 141 years making it hard to collect in bulk.
And there is absolutely zero chance of fusion solving our current energy crisis, the odds for fission are already low enough. There is no point on speculating on that.
This has been IMHO inappropriately hyped. We have an expected gas shortfall in Europe due to the mess made by one rogue actor (though Putin hasn't shut the pipes off yet, The existing price shocks are all speculative!). Petroleum production is fine. Gas production outside of Europe is fine. Existing interests in those industries have been exploiting the resulting price shocks (which are not the same thing as a crisis) to try to drive public policy decisions in their direction.
We've been here before in the 1970's when rogue actors tried to exploit their production capacity for political gain. It sucked, but we didn't get fusion out of it then either.
Frankly it's not even the first time we've had a supply shortfall. People tend to forget this, but we ran out of oil in the late 90's too! Turns out, there was lots more oil available at higher price points.
About mRNA vaccines I agree with you, because they indeed have been a niche thing before covid, but then they were the first available vaccines while the alternatives were still being researched when the first mRNA vaccines got their emergency approval. But how has CRISPR benefitted from covid? It doesn't seem to be used anywhere in therapeutics, no?
I imagine it's on the comment because it was used to create many of the non mRNA vaccines.
But I don't think it got popularized. It was already widely popular.
I don’t think it’s actually evolved all that much. They just deployed something that wasn’t really tested. I recall learning about theoretical mRNA vaccines back in 2014-2019 (granted they were killing the hosts and stuff). As someone who’s studied bioengineering (university, reading papers and some projects) I’d really like to see 10-15 years of usage before we consider anything with the tech.
I for one home we don’t do the same thing with fusion. There is an amazing amount of risk as technology has expanded, we have to be far more cautious.
We have the solution, it's removing the most egregious wastes of energy and using the sun to power the rest. It's the same solution that we've always had available, we just have to do the intelligent thing rather than the thing which gives more power to the powerful.
This isn't "cold".
Having read a few articles previous on fusion, I'm familiar with the words tokamak and stellarator, so it was obvious to me that it was about fusion from the title.
I wonder how many other titles you would consider opaque if you didn't happen to know the terms?
Hot fusion is a well-known process that powers the sun. Cold fusion is a supposed low-temperature process that most scientists doubt is real, and if it is real we don't understand the physics of it.
Also like to surprise people with a fusion process that works at temperatures in the single-digit kelvin range: https://en.wikipedia.org/wiki/Muon-catalyzed_fusion
But yes, the linked reactor isn’t that, and the thing commonly referred to as “cold fusion” probably isn’t real.
And the thread is just Blenk fans arguing with Fobl fans.
But if you take one glance at the comments, it becomes clear. So I guess the title was sufficient to pique my interest, which, after all, is the purpose of a title.