This might sound a bit like a buzz-kill, but I don't think fusion power is necessarily competitively cheap. I think it will be comparable to nuclear power with a ~ 10 times higher capital investment to build a fusion-plant. Already now solar is said to be cheaper then nuclear.
But nevertheless humanity should explore fusion since it is more or less the only significant power source not (indrectly) depending on the sun.
As far as I can see the funding of fusion research is at about the same level as particle physics which definilty does not provide any other than philosophical progress.
NO... humanity should explore fusion because we might desperately need it to survive.
To what amount can you scale up solar in a particular region?!
Yeah, I know, we're into low-power everything nowadays... but let's say that you end up with a desperate need for smth like 1 TW of power for something like a sea-water desalination plant, massive irrigation needs because climate change fucked you up, or building a huge set of flood barriers (think what Nederlands has now, but you need them 100x larger, 5x cheaper and done FAST) because sea levels rose and people will die if you don't get the massive cheap energy needs for these projects ASAP. Or maybe a huge TW power laser for some space-dev project if you don't want to think of disasters. Or maybe to decontaminate large amounts of water/soil/air after the first large-ish nuclear/bio/chemical war that will take place on Earth.
If you're betting on solar and wind and you end up suddenly needing high levels of cheap (it can be "long-term like 100 years on cheap" if you're a country with a good credit score) power, you're.... fucked! Yeah, fusion won't be scalable to massive energy needs "out of the lab", but in 100 years from now when your grandchildren will need it to save their lives from the consequences of our planetary fuck-ups, it will be!
(And yeah, short term you can scale fission better probably. So investment into "dirt-cheap fission power that anyone can have" is also crucial. But longer term it hits other scalability bounds.).
In a perfect world where we don't totally fuck-up the planet, solar and hydro and geotermal and wind and waves would be enough.
In the real world, where we will fuck-up the planet, things like fusion are desperately needed to un-fuck regions of it and re-terraform them (and also to get into space exploration fast and big, not "snail-paced solar-powered").
It's not engineering problems. It's assumptions about how humans will behave!
Maybe the region where solar needs can be scaled is not in your country. Maybe you're at war with that country. Or maybe the company producing that power would only sell you the power at some outrageous price that you don't want to pay. Maybe you want to be the one selling not buying that power, you want to be the one making profit. Maybe your neighbor just considers you're an inferior race so he will not even sell you the power for the flood dams or the desalination plant. Or maybe you're the bad guy, but now because people won't sell you what you need at realistic prices you contemplate of... maybe nuking some sense into them, because if 1mil of your people might die of hunger, why not have 2mil of theirs die burned and irradiated?
Any solutions that assumes people working well together in some "perfect world order" are very dangerous. Humanity ain't "a giant organism". We're a bunch of warring tribes with carefully disguised racist, xenophobic and even purely sadistical tendencies just waiting for an excuse to come out!
We need more technologies that just work and can be used SUSTAINABLY in any random place and at any scale regardless of how bad we fucked up or we're planning to fuck up.
Energy diversity and energy security are important.
On the one hand, global trade can strengthen relationships between nations and make war less likely. On the other hand, look at how Russia uses the threat of turning off gas supplies to pressure european countries.
A solar farm has higher energy density than you might think. New York City could get ~100 gigawatts of solar power without importing anything. Further, if anyplace used close to as much energy as provided by sunlight it would get really hot.
There's other reasons you might want fusion power: any place you need a large source of power, but siphoning off ambient energy (i.e. wind, solar) isn't feasible or sufficient, fusion is the way to go or else you have to use fission or fossil fuels.
This applies to things like ships and submarines, and to spacecraft.
So yeah, solar/etc. sounds great in an ideal scenario in a perfect world, but what if you're not on this world? Solar power isn't sufficient to do serious mining operations in the asteroid belt or to redirect a large asteroid threatening to impact the Earth. It also won't power your aircraft carrier or cruise ship. A clean source of nuclear power would be ideal for all these things, if we can figure out how to make such a thing work.
Fission fits the bill perfectly in the scenarios you posit and we have almost fifty years of hard-won production experience with it. Fusion isn't really 'cleaner' than fission for most practical purposes, so why pin your hopes on something we can't even do in a practical manner at the moment? Fission also scales down much better (or at least we know how to scale it down effectively) so the power plant is much more likely to fit into the spaces available in these examples.
How is fission possibly as clean as fusion? Fission leaves behind radioactive waste material; fusion leaves behind helium. This doesn't make any sense at all.
Yes, we can't do fusion in any practical manner at the moment, but we can't do fission scaled-down either: if you disagree, please show me an example which is economically successful. US Navy ships don't count (not "economically successful"). Someone actually tried building a fission-powered commercial cargo ship ages ago; it didn't last very long. It cost so much to operate that it was retired in a few years and sent to a museum in Charleston SC. With absurdly expensive fuel, nasty waste which needs to be disposed of somehow, and extremely dangerous operation requiring highly-trained personnel, fission plants only make commercial sense when they're scaled up to gigawatt scale power plants. Fusion plants may not be practical yet, but they'll never be practical if no effort is spent on R&D to make them that way.
Neutron bombardment of your fusion containment vessel creates radioactive material. I am not sure where you get this idea that fusion is 'clean', but everything that involves pushing around fundamental particles creates radioactive waste. There are theoretical designs for fusion reactors that limit the radioactive side-effects somewhat but nothing in this area is clean.
Scaled down fission reactors like the Toshiba 4S can be sized to power an apartment building or city block. There are numerous micro reactor designs available and a variety of companies working to try to create a market for them.
When it comes to terrestrial reactors then fusion reactors will be enormous (need to generate a lot of power to compensate for the huge risk and the massive costs that it will take to build them) and if you are talking about putting reactors in space then it is foolish to consider anything but fission for at least our lifetime.
Do you need 1TW tomorrow? If so, you are fucked, sorry.
Fusion takes longer to scale than any kind of power supply we use. At least H2 + H3 fusion, that is the easiest kind does. You'd be much better building a huge solar array on demand.
If things are that fucked, any given government will have no qualms building fission plants everywhere. If you aren't super-duper paranoid about safety and radiation, fission is already pretty damn cheap.
> This might sound a bit like a buzz-kill, but I don't think fusion power is necessarily competitively cheap.
Buzz kill on hn is fine so long as you back up your opinions with rational arguments and / or citations rather than simply sharing more of your opinions as ersatz supporting evidence.
> I think it will be comparable to nuclear power with a ~ 10 times higher capital investment to build a fusion-plant.
This is my biggest problem when talking with people about nuclear -- the conflation of fission and fusion. Saying fusion compared to nuclear is like saying diesel compared to internal combustion engine.
> Already now solar is said to be cheaper then nuclear.
And solar means multiple things too - PVC and thermal, for starters. But who says this, and why, and [!?] where?
> But nevertheless humanity should explore fusion since it is more or less the only significant power source not (indrectly) depending on the sun.
Fission fits this bill too, but obviously is less desirable.
> As far as I can see the funding of fusion research is at about the same level as particle physics which definilty does not provide any other than philosophical progress.
There's no benefit from particle physics other than philosophical?
To be fair, "nuclear power" has been used for decades as a shorter way of saying "nuclear fission power". I don't think any confusion arises when saying things like "nuclear compared to fusion".
The very high cost of fission has a lot to do with how nasty, awkward, long-lasting and expensive the fuel and waste are. We really won't know until we try building a power plant.
Much of the nasty stuff comes from the fact that current (light water) reactors were actually meant to produce military plutonium. Bombs first. Energy was a by-product, and a very nice way to sell nuke-making to the civilians.
There is another way of doing fission, that was demonstrated (working prototype and all) in the 60's: molten salt. You basically dissolve the fissile matter in molten salt, provide initial heat, and you have a reaction going. This has multiple advantages:
- Originally designed for a nuclear plane, it is capable of reacting to load changes very quickly. It's basically easy to power-up, and easy to shut down.
- It is amenable to a passive security set up: when all goes wrong, the reactor shuts down by default. When it does, the radioactive matter is trapped in no-longer-molten salt, such that contamination is limited even if there is a leak.
- It consumes 90% of the fissile matter before it has to go to recycling. (Current reactors do about 10%.)
- It currently produces 5 times less waste than current reactors. There is hope to do even better.
- Last but not least, it can run off thorium, which is 4 times more abundant than uranium, and much better spread out geographically.
With one or two decades and a few billion dollars, we could make commercial grade reactors. They would almost certainly be significantly cleaner, and much safer than current light water reactors. They could adapt to changes of demand in the power grid, or compensate for the volatility of most renewable power sources without the need for a "battery miracle". Overall, they would make a terrific mid-term solution, that could last a couple centuries. More than enough time to come up with something better.
I'm sure with some extra R&D people could make those reactors reliable, but if you search the new generation reactors on Wikipedia, you'll see every one of them ended in some kind of failure.
I'll wager this was mostly because of the lack of funding. Those reactors were not as thoroughly researched as the light water ones. In a sense, they're still stuck in the 60's. (Really, putting molten salt reactors in the "new generation" bucket is a bit of a joke. It's old stuff that was shut down mostly for military and economic reasons, and only recently got more traction.)
Another possible cause is path dependence. We have a whole industry around solid fuel, light water reactors. Switching to molten salt throws much of that away.
Much research still need to be done. We may want cleaner salts, we want even less radioactive waste, and we definitely want to accurately assess the safety of this stuff ("passive security" is not enough by itself). This means more prototypes reactors, of various sizes, each more expensive than before. We want a few million dollars for the small ones, then a few billions for the big ones.
I was serious when I said I was sure some extra R&D would solve those problems.
It may not be just lack of founding. Materials science has advanced a lot since then, and those problems look solvable now, but I'm not sure they could be solved by the 60's.
I don't know who in the thorium boosters' club started the "light water reactors were meant for weapons plutonium" meme but it's nonsense.
To quote "Technologies Underlying Weapons of Mass Destruction",
Reactor-grade plutonium recovered from civilian reactors differs from weapon-grade plutonium in the relative proportions of various plutonium isotopes. Reactor-grade plutonium has a higher rate of spontaneous fission reactions than weapon-grade, generating neutrons that can initiate the nuclear chain reaction during weapon detonation sooner than would be optimal. As a result, using reactor-grade plutonium in a first generation nuclear weapon can significantly reduce both the predictability and the expected yield of a weapon designed by a proliferant state.
None of the states that have either made nuclear weapons or attempted to do so appear to have selected anything but high-quality plutonium or uranium for their designs. Nevertheless,
from a technical perspective, reactor grade plutonium can be used to make nuclear weapons, and any state possessing significant quantities of separated plutonium should be considered to have the material needed to fabricate nuclear components for nuclear explosive devices in a short period of time.
If you want to seize on the part where it says that one could build bombs from civilian reactor waste even though it's less straightforward and no nuclear weapons state has ever done that, then I'll point out that the thorium fuel cycle likewise could be used for bombs even though no NWS has ever taken that path (Quoting LANL's "Thorium Based Power Systems and Relevant Safeguards Considerations"):
Thorium is not safeguarded until it is converted into fuel materials. It would seem that if the starting point for uranium safeguards is moved up and thorium begins to play a larger role in the global nuclear establishment, then thorium safeguards should move to the equivalent point in the thorium fuel cycle.
Unlike thorium, U-233 is subject to stringent safeguards. An SQ of U-233 is only 8 Kg, the same as plutonium. U-233 is a highly desirable weapons material despite any practical U-232 content. According to the material attractiveness studies done at LANL, PNNL and LLNL, the additional dose from U-232 decay products is insufficient to stop a determined adversary. While it may be somewhat beneficial to physical protection, the dose rate is not high enough to incapacitate workers. Dose rates can be greatly reduced with shielding and military personnel handling a fabricated weapon should be able to have reasonable dose rates using established techniques. For example, the pit can be stored in lead shielding and only placed in the weapon immediately before use.
The actual military lineage of civilian LWRs is that the US Navy developed pressurized water reactors fueled with enriched uranium to power vessels in the 1950s, starting with USS Nautilus. That variety of reactor had the fewest unknowns when the civilian nuclear industry first developed in the US and the path dependency effects continue today.
I'm inclined to believe modern civilian reactors are terrible at producing bomb worthy plutonium. Indeed, the main goals quickly became energy and safety.
However, this was probably not the case for the first reactors. If I recall my documentary properly "la face gâchée du nucléaire" (French and German only I'm afraid), the technology was initially chosen because it could produce plutonium. Therefore it got lots of research, and naturally ended up working best.
Submarines were of course responsible for much of the continued funding. Molten salt got cut off in no small part because the very idea of a nuclear plane was not very good.
That said, I'll need to study this subject more closely before I consider myself properly informed.
It is not surprising that a pro-thorium documentary includes the same misstatements about uranium fueled light water reactors that have spread in writing.
The very first reactors were indeed built for plutonium production. Those 1940s reactors built in Hanford, WA, USA used unenriched natural uranium for fissile material, used purified graphite as their neutron moderator, and did not generate any useful energy. In fact they were net energy consumers because they needed an external power source to move water through to keep them cooled.
Shippingport literally started with a surplus naval reactor from a cancelled aircraft carrier project. It was a pressurized light water reactor requiring enriched fuel like most reactors now operating commercially. Everything about it was different from the early plutonium reactors: the fuel, the moderator, the heat exchange... by a funny coincidence, Shippingport was also the only commercial reactor in the US to use the thorium fuel cycle, from 1977 to 1982.
>I don't know who in the thorium boosters' club started the "light water reactors were meant for weapons plutonium" meme but it's nonsense.
Maybe the misunderstanding started from the fact that the first British power-generation reactors were intended to produce weapons-grade plutonium. Those reactors were quite different from light-water reactors: graphite-moderated, gas-cooled, and using unenriched fuel.
Fusion produces energetic neutrons, and energetic neutrons are a very good way to make things radioactive. So all the popular approaches create waste that is more radioactive than fission waste, and probably comparable in volume.
The only up side is that the decay products have a shorter half life. So the waste will only be a problem for a century or so, instead of for millennia.
This may be better than fission, but it's definitely not clean by any realistic definition of the word.
The advantage with Fusion is that you can control what elements are exposed to the neutron flux and so control what sort of new elements or isotopes you get. For instance there's basically nothing in the air except for dust that will absorb a neutron and turn into something you have to worry about. And part of the design of a fusion reactor is to use lithium to absorb as many neutrons as possible to breed tritium to feed back into the reaction.
By contrast the byproducts of a fission reaction are set by the fuels used and include really nasty stuff like Strontium-90 and so on. But even fission plants are designed so that the radioactive byproducts are essentially all spent fuel or things contaminated by spent fuel. Neutron activation is a design consideration rather than a source of waste.
Of course the neutron flux will tend to enbrittle the metals used in it's construction which will have the effect of increasing maintenance costs.
Uranium mining is a nasty business. Deuterium concentration is, by comparison, just a bunch of water-filled centrifuges. Surly that would make a large difference all on its own, no?
> The only up side is that the decay products have a shorter half life. So the waste will only be a problem for a century or so, instead of for millennia.
This sounds like a tremendous underestimation of the problem - handling waste.
We have people who live 'for a century or so' but we don't even have languages (now!) that have lasted a millenia.
Our current "decay product" of energy generation (carbon) is going to impact our world for a lot longer than a century. I'll take known-quantity, manageable century-long decay products over unknown-quantity, nearly unmanageable (large-scale carbon sequestration is hard) any day.
You might make the case that MSA and Classical Arabic is an exception, but MSA is not spoken natively AFAIK. Other than that, I cannot think of any examples where a language spoken by someone a thousand years ago would be intelligible now. Languages change in sound, structure and vocabulary over time naturally. That's how we got the Romance languages from Latin (which is no longer spoken).
However, language standardization artificially slows down change, so current languages might last a lot longer. English hasn't changed that much since Shakespeare and the KJV.
Maybe interesting to you: https://en.m.wikipedia.org/w/index.php?title=Conservative_(l...
Yes, for written form you could make that argument, though there are some differences between the two. Also, it didn't really "last" in the normal sense, since it was revived in modern times.
Also, Tibetan maintains the same spellings from 1200 years ago, but that really just means that it's very, very difficult to spell, since the pronunciation no longer matches spelling well.
These make interesting exceptions to the general rule, so I think the original point is still very valid. I'm curious about old vs. modern Syrian, if anyone knows about that.
Okay, point taken - we certainly do have some languages still in use that that have lasted more than a millennia.
I'd posit that storage is not a solved problem, and a big part of that is a lack of confidence that we can reliably communicate with the people who will have to deal with this waste in the distant future.
There's also the inherent disdain involved in passing on massive costs and risks to future generations to solve a comparatively short-term problem of ours.
Not really, fusion needs to keep the reaction in a near vacuum where fission uses a multi loop system which creates a lot more surface area and waste. Further the blanket needs to be made from lithium to make tritium in a DT fusion setup capturing those fast neutrons without creating long term waste.
Most importantly they are vastly safer and thus need far less security and far less insurance. Remember a huge benefit for PV solar and wind is they don't need guards.
PS: Another consideration is the half life is short enough that over 20 years things become a lot less radioactive. Fission has some half lives just long enough to be a real pain.
I don't think fusion power will be "too cheap to meter" just like fission wasn't anywhere near that. However, I do think we'll be able to make fusion reactors that are much more compact, like what Lockheed Martin is trying to build. I also think we'll achieve significantly more power/volume, which will be very useful for space ships in the future.
I agree - always been a bit mystified when fusion power is described as "cheap", fuel isn't a big component of the cost of fission power plants so even if the fuel is low cost it won't save you that much money.
[I guess decommissioning costs might be lower but are they actually included in the costs of operating normal nuclear plants?]
I bet regulatory compliance is a big chunk of the costs. Those regulations are bound to be much more strict for a fission plant that can potentially blow up and contaminate a large area compared to a fusion plant with a safe failure mode by default (the plasma just shuts down).
The worst case scenarios for an accident at a fusion plant aren't nearly as bad as those at a fission plant so you should be able to get by with somewhat less in terms of paranoid safety measures and overbuilding.
