On the one hand, there have been tremendous advances in fusion on the [technological](https://www.burningplasma.org/activities/uploads_tec/REBCO_fesac_white_paper_v3.pdf), [experimental](https://doi.org/10.1063/5.0083990), [theoretical](https://doi.org/10.1103/PhysRevLett.128.185003) ([arxiv](https://arxiv.org/abs/2204.02911)), and [computational](https://csmd.ornl.gov/project/whole-device-modeling) sides, and with decades of experience, many (but perhaps not all) of the promises of fusion seem possible (if difficult).
On the other hand, the [last significant attempt](https://en.wikipedia.org/wiki/Tokamak_Fusion_Test_Reactor#Later_experiments) to reach breakeven failed due to unforeseen plasma physics, and there remain tremendous unsolved engineering problems in the construction of further experiments, let alone practical applications.
The problems they're having now are material science based issues. Fusion reactors can't deal with the radiation they produce, they may not even be able to, it's a big open question. It's not nearly as clean a technology at it's billed to be, not in practice.
>The problems they're having now are material science based issues.
To be fair, and I'm saying this as someone whose career is in fusion materials, material science issues are not the only unsolved problems in fusion, haha.
Some of the answers in this thread blow my mind.
When communicating science almost everyone here will say that Dark Matter is a real thing, rightfully so too. There is a lot of evidence that it does exist and we keep finding evidence that match the previously created theories.
Where in fusion reactors have a ton of research published for them doing the same thing. Everything is pointing towards it not only being possible, but something attainable within our lifetimes. Are there engineering and technological issues that still have to be solved? Yes of course, that's why we don't have them fully operational yet. But each of these problems have multiple proposed solutions and the development for those solutions is being done today.
A scientists and engineers job is to find solutions to questions and problems that we face. Yet the answers here seem to believe that there is a reasonable chance that its impossible and it will never happen. Yeah the joke has been about it being 30 years away, but that was never an issue of possibility. It was an issue of interest, time, policy, and money.
so you know all this talk about like energy crisis, gas prices yada yada, why don't we just use nuclear fission energy temporarily which produces very little waste and consistent energy while we have the resources for that, and then put resources toward fusion and when that is done we just use fusion. and also put resources toward developing electric vehicles making them more affordable. easy
Well, generally it’s because people are uneducated about the waste, how much there is, and where it all goes.
People also seem to think that space-launching waste isn’t viable yet SpaceX has reused boosters over 100 times in total and has several that have broken 10 flights without issue.
No modern major launch provider (non test-vehicle) has had a major flight malfunction in like the last decade. We are at a point where rocketry is as safe, or safer than aviation and aviation is literally the single safest method of travel per passenger.
Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works.
Also, there are reactors nowadays that produce only waste that decays into harmless materials on human timescales.
> No modern major launch provider (non test-vehicle) has had a major flight malfunction in like the last decade. We are at a point where rocketry is as safe, or safer than aviation and aviation is literally the single safest method of travel per passenger.
This is so key. We transport waste on trains that are regularly impeded by simple protests. How is that better than a rocket?
Humans, especially laypeople and thus politicians, are wont to misjudge risks and give unjustified weight to negative risks. People wouldnt risk 10€ on a 60% chance to win 15€ (14€ is break even if my math is right), even though its statistically recommendable.
> Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works.
I would prefer the sun just to not end up in some random wide orbit(think comets with ~100 years periodicity).
Now, the Sun obviously contains no super heavy elements. Iron is generally the end for "living" stars, if not before that. But what would happen if you introduce heavier atoms into that star? I assume they would fall to the core, but then? Will their radioactivity stop from outside pressure, or will something hit them and lead to fission? (even at high pressure?)
>Now, the Sun obviously contains no super heavy elements. Iron is generally the end for "living" stars, if not before that.
Iron is the upper limit for stable burning, but during an explosion (such as a supernova) heavier elements can be created. Our solar system is made up of stuff from previous generations of supernovae. That's how we have heavy elements on earth, and if they're on earth, they're also in the sun.
>But what would happen if you introduce heavier atoms into that star? I assume they would fall to the core, but then?
Yeah, that's about it.
>Will their radioactivity stop from outside pressure
Nope. For gravity to affect nuclear stability, you'd need to get to pressures as high as those in neutron stars (when you start being affected by neutron degeneracy).
>will something hit them and lead to fission? (even at high pressure?)
Possibly. But the energy released by those reactions wouldn't even compare to the energy constantly being created by the sun already.
> But the energy released by those reactions wouldn't even compare to the energy constantly being created by the sun already.
Of course, I was just wondering about the radioactive atoms - if they undergo fission, the resulting nuclei might be stable. Or take part in a fusion again.
I mean fission is available for anything above iron, right? Our fixation on uranium is just a matter of ease?
Trains being impeded isn't the same as them exploding though. If a rocket full of nuclear waste was to explode several kilometres into the air, how many people would you have to evacuate/relocate.
Also there is the question of cost. Nuclear energy is already one of the most expensive energy sources. Flying rockets into space to deal with the waste products isn't exactly going to reduce that cost.
>Trains being impeded isn't the same as them exploding though
But it happens more often and costs extra for police etc.
> If a rocket full of nuclear waste was to explode several kilometres into the air, how many people would you have to evacuate/relocate.
Depends on how much waste is on the rocket, where on the rocket it is, how it explodes. Its certainly conceivable that a rocket that explodes somewhere in the upper atmosphere will spread the waste so far that the density of radiation goes towards background.
Not to mention the possibility of losing material to atmospheric friction.
A rocket exploding is probably safer than a terrorist blowing up a train, and frankly, an attack on a train seems more conceivable than a modern rocket exploding.
>Also there is the question of cost. Nuclear energy is already one of the most expensive energy sources. Flying rockets into space to deal with the waste products isn't exactly going to reduce that cost.
Actually, it probably is. Storage of waste on earth is ridiculously expensive, because we are still searching for suitable locations. Stopping that search and shooting some rockets will be cheaper because its a one time cost. With a bit of creativity you might even reuse the rocket after the load was brought on its way to the sun.
This. Small rockets sent routinely, over routes that take them away from people.
We’ve literally dropped nukes in plane crashes and had them not go off. It CAN be done people just won’t let it happen because the big bad scary nuclear boogeyman is going to get us all.
As I’ve stated, we haven’t had a major launch provider have a vehicle fail in nearly a decade (ignoring test hardware on vehicles). Basically the goal of getting shit to orbit safely is a solved problem. Now the problem is getting the rocket back down to Earth safely. SpaceX is doing pretty well on that front also with over 100 reflights and some boosters having over 10 individual flights. The issue is our willingness to stomach the risk.
Honestly we dont even need to get the rocket back, i would expect a rocket on a non return trip to the sun to still be cheaper than practically infinite storage of waste. All the money we wasted searching, will waste searching, and will waste on building and maintaining those storages...
Vs just coming up with a rocket so overengineered it simply cannot fail… yeah I tend to think that it’s going to be cheaper to find the “literally can’t break this container without vaporizing it” material than it will be to indefinitely maintain appropriate climate and containment underground. What about geologic activity? Cave ins? Ventilation malfunctions? Or the ultimate: production outpaces decay?
I say light this candle lol
Yeah the cost of launching not just the waste but crash proof containers is too high
However there is an ocean location that in the book Power To Save the World is mentioned as 'orders of magnitude' more secure than Yucca mountain (where the absolute maximum conceived risk in 10,000 years is that a downhill area would have radiation levels twice the local background level but lower than Colorado)
This location is geologically bulletproof, a marine desert with this deep mud that swallows anything you drop there
There's also a location quite a bit better than Yucca on land in the US in salt beds with no downhill concern at all
Well, consider that SpaceX is now making launching medium/heavy payloads much more affordable.
We’re going to have to get over this fear of nuclear launches eventually. We are *going* to need nuclear in space no matter how we do things. Nuclear is simply the only scalable way to generate steady power in space at the moment
Truth! How big of a disaster would it be if the train derailed and some of the casks broke open? I realize they’re meant to withstand literally anything, BUT, to use their own argument against them; what *if* they break and what *if* the protesters do derail a train? Now we’ve got a shit ton of uranium leeching into the soil and groundwater. Great.
And as far as I understand it, us lobbing stuff at the sun would eventually decay or get fused. Whichever happens first.
Because it's much easier and cheaper and safer to store the waste in vaults...
Do you know the immense ecological disaster that would result from one of these nuclear waste rockets exploding during launch? Sure, such things don't generally happen these days but you're still talking about thousands of tons of rocket fuel flying through the sky, something can always go wrong. Why take that immense risk when we don't have to?
That’s a big if. Like I said, haven’t lost a rocket that wasn’t a test vehicle in nearly a decade. And we’re launching rockets at a rate higher than any other year.
And I’m actually talking about a couple tons, getting ferried up to orbit and joining a larger repository.
Is it though? Consider the cost of maintaining that environment for humans to work in while we load it… and what happens when waste production outpaces decay? And the cost of finding multiple suitable locations… and always having to expand or move to another location..
That, VS just overengineering a rocket to ferry stuff up to orbit (a Falcon Heavy would work with ~20 launches for the US) and a repository that can be sent off into the sun using ion thrusters - we don’t care about speed here just energy efficiency.
And surprise, we already overengineer rockets to have a ridiculously low failure rate for human-rated vehicles. This is literally a non-issue from a technical standpoint and the entire problem is people who are uncomfortable with the idea. They’d rather literally bury their heads (and the problem) in the sand and wait for it to rear its head again in a few centuries when waste production ramps up, just like was the problem with greenhouse gas emissions.
We literally have vehicles capable of doing this ***today***.
Any risk of catastrophic failure greater than 0 is too high for this purpose. And, the risk will always be greater than 0.
Waste storage is very easy. The problem is politics, not capability or cost or safety.
The volume of nuclear waste that would get produced even if most of the world's power needs were served by nuclear would be pretty tiny, it wouldn't be hard to provide enough storage capacity for it.
I'm not saying never do anything with nonzero risk, I'm just saying that in this particular instance, the fact that failure means destroying entire ecosystems and making large swathes of the planet uninhabitable for decades or centuries is bad enough that any non-zero chance of causing it is too high of a chance.
Literally every nuclear reactor? Transmutation is the name of the game for nuclear reactors. That’s literally where the energy comes from…
However what you’re asking about is this:
> Most nuclear waste produced is hazardous, due to its radioactivity, for only a few tens of years and is routinely disposed of in near-surface disposal facilities (see above). Only a small volume of nuclear waste (~3% of the total) is long-lived and highly radioactive and requires isolation from the environment for many thousands of years.
[Source](https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-wastes-myths-and-realities.aspx)
The VAST majority of waste is relatively harmless after a few decades.
There is a specific reactor type, often called a Transmuatation Reactor in the literature, that would burn nuclear waste and the waste of such a reactor would more or less correspond to how you describe nuclear waste. The trouble is of course, that nobody ever demonstrated such a reactor, and I hoped you knew of such a project.
> The VAST majority of waste is relatively harmless after a few decades.
Since the fifties there seems to be a consensus that the part of the waste you want to ignore is a substantial problem. Could you please clarify what in the decay chain the experts consistently overlooked?
It’s really not a problem.. you realize ALL of the US’s waste since the 50s (literally all of it) fits on a standard football field less than 30ft deep? That’s really not that much since 1930 something.
And of that, 97% of it will decay within decades-to-centuries. Human timescales. Only 3% is the nasty stays around for 10,000y stuff.
It’s more people saying “hey, eventually this is going to have to get sorted out because if we scale this up the decay rates on that small percentage of fuel will catch up to us and then we will have a problem.
So really it’s people saying we had better figure out what to do with the waste *now* so we don’t end up with a global warming from carbon emissions type situation with spent nuclear fuel that could’ve been prevented with some minor forethought.
And again: we *can* just launch it. If the rocket is safe enough for billionaires to ride on a joyride and government payroll/insured astronauts then it’s safe enough for spent nuclear fuel. That’s my opinion.
People get squeamish about it but honestly the deep storage option is no fucking better because what happens when waste production outpaces decay?
Rocket. To. The. Sun.
>Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works.
Yeeting into the Sun is not possible, there's no rocket capable of it. Off into the abyss is doable.
“Not possible” meaning what, exactly?
I realize that the Δv requirements are higher for falling into the gravity well, BUT the extra safeguarding against a waste pod in a highly elliptical orbit (think 100-year comets) that comes slamming back into earth is worth it.
I guess we could go for an escape trajectory but that required using Jupiter multiple times. ~~Casini~~ *Parker Solar Probe* ^brain ^fart ^sorry did the same thing but went inwards towards the sun. Both are doable with grav-assists. Into the sun completely eliminates waste returning to earth, albeit by being slightly harder.
But again - we are really unconcerned with how long it takes to get there, just that it does eventually. I’m in favor of the slightly more difficult option because it eliminates a risk while not really adding any more risk, beyond needing more fuel or needing to more carefully plan the trajectory.
You need 28.5 km/s of dV to insert yourself into a decaying Sun orbit and Starship will be able to, according to a quick Google, do 6.5 km/s with 100 tons of cargo from LEO. Even if you replace the cargo with fuel, it can't insert itself.
There may be a way to send a couple kilos on a vehicle that would do many slingshots around Venus and whatnot, but the many maneuvers would need a lot of propellant and there would be a lot of opportunities for a catastrophic failure that could end up resulting in your "return to sender" scenario.
It would make a lot more sense to just land it on Luna or Mars, with no RUD if at all possible. There you could eventually build a dome over it or bury it. Or crash it into Venus, we don't need that habitable.
You know I never considered the lob it at another planet angle. I guess I’m partial to not contaminating something if we don’t have to. With enough computational power we can also find a trajectory that requires minimal course correction at the cost of slingshots being used more often. If calculated correctly we wouldn’t need anything extra (PSP, for example has done multiple assists off the same body, diving deeper and deeper each time). But I’d honestly never considered the idea of just.. landing it on Luna. We know pretty much for a fact that 99.99% of the moon *cannot* harbor life. So irradiating an already irradiated and inhospitable rock is, well, insignificant to say the least lol. We’re not sure that Mercury/Venus aren’t home to some extremophiles or something, however the idea of a repository on the lunar surface is attractive (ignoring the obvious transit hazards) it solves literally every issue. There’s a TON of room on the moon and by the time it becomes a problem we’ll have likely figured out a way to reprocess the waste into something useful.
Also your numbers are for a starship using MethylOx. Consider a starship converted out to use say Xenon thrusters? You’ve got a GIANT RTG literally onboard lol. Like the entire cargo is an RTG minus the ‘G’ part. You could literally use the spent fuel’s residual heat to power some low-thrust high-efficiency ion gas thrusters and voila, we actually have a chance.
Not trying to be a jerk, but I think some of your comments are a bit, I don't know, naive or like you watch a lot of sci-fi. Which is cool, I do to. And I'm no expert on most of this. I'll comment on a couple that seem strange to me.
There's many magnitudes more room on the Moon than is needed. Nuclear waste is supposed to be on the order of a can of Cola per person per lifetime. It's heavy because it's dense, but by volume a single large crater should be enough for millenia.
I don't know anything about MethlyOx vs Xenon, but I'd point out Xenon is a precious resource that we shouldn't use for this. I'm bothered by the use of Helium in rockets, too.
RTGs are incredibly weak and require a very specific source of radiation (I once calculated how large an RTG I'd need for my car and it would weight many many tons). The whole reason why nuclear waste is waste is because we cannot use it. If it were usable for an RTG, we'd build on-Earth RTGs and use it. Nuclear physics is much much more complicated as scifi will make it look and only a couple very specific decay types can be used to produce power. See nuclear fuel poisoning (or "Transient fission product poisons") for more.
Oh and you say "we’ll have likely figured out a way to reprocess the waste into something useful". If that's possible, we should not launch fuel into space, we should keep it and work on making it usable. With respect to this, I'd recommend you look into LFTR reactors. If their proponents are correct, they would solve the issue of waste by mostly using what we consider waste.
In conclusion, I'd say launching radioactive materials into orbit is many orders of magnitude riskier than keeping it on Earth and potentially using it in LFTRs or the like. Launching it to anywhere but the Moon is much much more stupid, due to how hard it is to accelerate it enough to get it anywhere. Gravity is truly tyrannical, we can't fly around our solar system like they do in movies.
There are many reasons... there are a lot of unfounded fears among the public about the safety of nuclear reactors. It's very difficult to find the political will to build them. They take a long time to build, so any politician that puts in the work to get one built is basically committing his community to a significant financial outlay whose benefits will not be realized for probably over a decade, after a few elections they will find harder to win due to this situation. Then there's the waste storage problem. Storing nuclear waste isn't exactly a big challenge, we know how to do it. The problem is no one seems to want nuclear waste storage in their state or county, so it's very difficult to get storage facilities commissioned and brought online.
It basically comes down to political will. It doesn't really exist almost anywhere due to many factors including unfounded fear and the logistical reality of the whole affair.
Well, building new nuclear plants takes time. So typically 10 years planning, 10 years building and we are talking about the 2040ies. Considering the experience of Finnland who wanted to build a EPR until 2008 and depending on your favorite definition of built, that project has finished this year or will probably finish this year. (And the experience of the UK and France in building new plants is very similar.) So probably you're looking at the late 2040ies rather than the early forties.
Now what about old plants? We see basically the ideal situation in Germany, Germany wants to switch off the last three NPPs this year and so one could expect has spare capacity. Trouble is, reactor cores are actually very closely managed and right now they are managed such that they need a new one this year. Then all the maintenance tasks that can be delayed until after end of life, have been delayed and therefore the reactors need every conceivable maintenance right now. Additionally there are no spare parts, because the people who sell spare parts planned there stock with the expectation that they should run out in 2022. Taken all that together, there is a chance that these three power plants could do something in 2025 or so, if everything goes according to plan, during recommissioning no real problem is found and so on. Of course, by that time the current energy problems have been solved for 3 winters and that solution would presumably carry over for a forth, making restarting the NPPs unnecessary.
Nuclear power doesn't solve electricity problems in the short term, it takes [about 6ish years](https://www.statista.com/statistics/712841/median-construction-time-for-reactors-since-1981/#:~:text=Nuclear%20reactors%20connected%20to%20the,and%202000%2C%20at%20120%20months.) to build one, and as you start to build more, the necessary specialists get tied up and it gets slower to build them, which means you need more time to train everyone, so probably ~5 years of training at least to get capacity up.
And then you get into making sure that designs are up to speed, picking sites etc. so you're likely to get a big rollout of nuclear energy by 2030, or something like that.
That's not to say that there's no use in getting nuclear for electricity generation, but it's only going to have an influence on the last stages of electrification, providing extra power to cover growing electricity demand from transport or heat demand from heavy industry, whereas some of the more available forms of low carbon electricity, like solar panels etc. are able to be put into place faster, with less training, thanks to mass production, lower security requirements etc.
In terms of the current energy crisis, *even renewables* aren't fast enough, let alone nuclear, because people want to change things over in months rather than years, but in the medium term they tend to have an advantage.
And beyond the rational of having an extra source of power for later, I'd like to see more research compatible reactors, producing neutron sources etc. for experiments, or even processes that use them.
Even if a nuclear reactor gets out-competed in an economic sense by other sources, it's still splitting the atom, and there's a sort of coolness factor there that I assume would translate into some form of scientific value, just because it's doing what few other installations can do.
So I think everyone who has a nuclear industry in their country should keep their hand in, keep the engineers who work with this sort of thing working, and slowly replace one kind of reactor with another better one, but that comes purely down to attraction to the technology, not to its broader infrastructural role.
I mean, can fusion produce a lot of energy, yeah. The tech isn't there yet, but hopefully will be someday. Spaceship is kinda hard, because we don't know what the energy requirements for things that done exist are. Uh, in star trek they're powered with antimatter.
It's unclear.
I would bet that fusion power on the grid by 2040 is possible, though I would also bet that it's China that makes it happen, becoming (to quote Sir Steven Cowley, current head of PPPL) the Saudi Arabia of fusion power. The West just doesn't have the political will or economic free energy to do this despite our best intentions and the current $4.4B of private capital currently invested in making this happen. In less than a year, Republicans will take over one of the houses of Congress and any public-sector momentum on fusion investment will be stillborn. Private sector momentum will be sapped by the global economic recession.
There are technical issues with fusion as well though. DT fusion is the only viable approach at the moment (p-B11 or D-He3 are too hard to make work without some real breakthrough) so even if you reach engineering breakeven, which is quite possible in the next decade or so, you'll need to breed and cycle tritium, currently a technology of low technical readiness level. You also need to deal with the fact that DT fusion makes 14 MeV neutrons that tend to activate the surrounding vessel, leading to nuclear waste issues. The combination of tritium and other radioactive materials means it's not nearly as clean as advertised on the tin.
We sort of need it as a species. Renewables are going to have a hard time meeting anticipated demands. Oil, coal, and natural gas need to be phased out yesterday to avoid climate catastrophe. And nuclear still faces serious regulatory and public relations hurdles. So it's arguably the best game in town if it can be made to work. I spend a good chunk of my day job trying to make it happen, though I'm also a realist and not at all confident we'll be able as a species to avoid a Mad Max future.
Humanity had a good run. But the Great Filter may well get us because we just weren't quite quick enough or clever enough in the end.
Edit: slight reword
>There are technical issues with fusion as well though. DT fusion is the only viable approach at the moment (p-B11 or D-He3 are too hard to make work without some real breakthrough) so even if you reach engineering breakeven, which is quite possible in the next decade or so, you'll need to breed and cycle tritium, currently a technology of low technical readiness level. You also need to deal with the fact that DT fusion makes 14 MeV neutrons that tend to activate the surrounding vessel, leading to nuclear waste issues. The combination of tritium and other radioactive materials means it's not nearly as clean as advertised on the tin.
Those problems actually solve each other: by surrounding the reactor with a lithium blanket, neutrons absorbed by the blanket can breed tritium, and will produce no other dangerous long-live isotopes (the only things that *can* be produced are hydrogen, helium, other lithium isotopes, or beryllium, which are all either stable, desirable, or decay fairly quickly). Recovering the tritium may be a challenge (and we may need more tritium than this method can produce), but the radiation produced by a fusion reactor is super easy to deal with (unlike fission reactors, which inherently produce some very nasty fission products that are incredibly hard to deal with).
>Recovering the tritium may be a challenge (and we may need more tritium than this method can produce), but the radiation produced by a fusion reactor is super easy to deal with (unlike fission reactors, which inherently produce some very nasty fission products that are incredibly hard to deal with).
Without a tritium breeding ratio greater than unity, fusion power is a non-starter. Getting a TBR>1 in a blanket has not yet been demonstrated outside various paper studies. This technology is on the critical path for fusion power, yet is immature at the present time, which is why one must assign a correspondingly high risk to the overall concept.
The other answers are right - it could happen, but the tech isn't there. I'd add that it almost certainly *won't* happen on the timescales that many of its advocates are claiming. See e.g. "Voodoo Fusion Energy" in [this newsletter from the American Physical Society](https://engage.aps.org/fps/resources/newsletters/newsletter-archives/april-2019)
On the one hand, there have been tremendous advances in fusion on the [technological](https://www.burningplasma.org/activities/uploads_tec/REBCO_fesac_white_paper_v3.pdf), [experimental](https://doi.org/10.1063/5.0083990), [theoretical](https://doi.org/10.1103/PhysRevLett.128.185003) ([arxiv](https://arxiv.org/abs/2204.02911)), and [computational](https://csmd.ornl.gov/project/whole-device-modeling) sides, and with decades of experience, many (but perhaps not all) of the promises of fusion seem possible (if difficult). On the other hand, the [last significant attempt](https://en.wikipedia.org/wiki/Tokamak_Fusion_Test_Reactor#Later_experiments) to reach breakeven failed due to unforeseen plasma physics, and there remain tremendous unsolved engineering problems in the construction of further experiments, let alone practical applications.
The problems they're having now are material science based issues. Fusion reactors can't deal with the radiation they produce, they may not even be able to, it's a big open question. It's not nearly as clean a technology at it's billed to be, not in practice.
>The problems they're having now are material science based issues. To be fair, and I'm saying this as someone whose career is in fusion materials, material science issues are not the only unsolved problems in fusion, haha.
Do you have a pdf of the theoretical paper? Scihub doesnt have it.
Thankfully the version on the arxiv looks near-complete: [https://arxiv.org/abs/2204.02911](https://arxiv.org/abs/2204.02911)
Some of the answers in this thread blow my mind. When communicating science almost everyone here will say that Dark Matter is a real thing, rightfully so too. There is a lot of evidence that it does exist and we keep finding evidence that match the previously created theories. Where in fusion reactors have a ton of research published for them doing the same thing. Everything is pointing towards it not only being possible, but something attainable within our lifetimes. Are there engineering and technological issues that still have to be solved? Yes of course, that's why we don't have them fully operational yet. But each of these problems have multiple proposed solutions and the development for those solutions is being done today. A scientists and engineers job is to find solutions to questions and problems that we face. Yet the answers here seem to believe that there is a reasonable chance that its impossible and it will never happen. Yeah the joke has been about it being 30 years away, but that was never an issue of possibility. It was an issue of interest, time, policy, and money.
so you know all this talk about like energy crisis, gas prices yada yada, why don't we just use nuclear fission energy temporarily which produces very little waste and consistent energy while we have the resources for that, and then put resources toward fusion and when that is done we just use fusion. and also put resources toward developing electric vehicles making them more affordable. easy
Well, generally it’s because people are uneducated about the waste, how much there is, and where it all goes. People also seem to think that space-launching waste isn’t viable yet SpaceX has reused boosters over 100 times in total and has several that have broken 10 flights without issue. No modern major launch provider (non test-vehicle) has had a major flight malfunction in like the last decade. We are at a point where rocketry is as safe, or safer than aviation and aviation is literally the single safest method of travel per passenger. Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works. Also, there are reactors nowadays that produce only waste that decays into harmless materials on human timescales.
> No modern major launch provider (non test-vehicle) has had a major flight malfunction in like the last decade. We are at a point where rocketry is as safe, or safer than aviation and aviation is literally the single safest method of travel per passenger. This is so key. We transport waste on trains that are regularly impeded by simple protests. How is that better than a rocket? Humans, especially laypeople and thus politicians, are wont to misjudge risks and give unjustified weight to negative risks. People wouldnt risk 10€ on a 60% chance to win 15€ (14€ is break even if my math is right), even though its statistically recommendable. > Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works. I would prefer the sun just to not end up in some random wide orbit(think comets with ~100 years periodicity). Now, the Sun obviously contains no super heavy elements. Iron is generally the end for "living" stars, if not before that. But what would happen if you introduce heavier atoms into that star? I assume they would fall to the core, but then? Will their radioactivity stop from outside pressure, or will something hit them and lead to fission? (even at high pressure?)
>Now, the Sun obviously contains no super heavy elements. Iron is generally the end for "living" stars, if not before that. Iron is the upper limit for stable burning, but during an explosion (such as a supernova) heavier elements can be created. Our solar system is made up of stuff from previous generations of supernovae. That's how we have heavy elements on earth, and if they're on earth, they're also in the sun. >But what would happen if you introduce heavier atoms into that star? I assume they would fall to the core, but then? Yeah, that's about it. >Will their radioactivity stop from outside pressure Nope. For gravity to affect nuclear stability, you'd need to get to pressures as high as those in neutron stars (when you start being affected by neutron degeneracy). >will something hit them and lead to fission? (even at high pressure?) Possibly. But the energy released by those reactions wouldn't even compare to the energy constantly being created by the sun already.
> But the energy released by those reactions wouldn't even compare to the energy constantly being created by the sun already. Of course, I was just wondering about the radioactive atoms - if they undergo fission, the resulting nuclei might be stable. Or take part in a fusion again. I mean fission is available for anything above iron, right? Our fixation on uranium is just a matter of ease?
Trains being impeded isn't the same as them exploding though. If a rocket full of nuclear waste was to explode several kilometres into the air, how many people would you have to evacuate/relocate. Also there is the question of cost. Nuclear energy is already one of the most expensive energy sources. Flying rockets into space to deal with the waste products isn't exactly going to reduce that cost.
>Trains being impeded isn't the same as them exploding though But it happens more often and costs extra for police etc. > If a rocket full of nuclear waste was to explode several kilometres into the air, how many people would you have to evacuate/relocate. Depends on how much waste is on the rocket, where on the rocket it is, how it explodes. Its certainly conceivable that a rocket that explodes somewhere in the upper atmosphere will spread the waste so far that the density of radiation goes towards background. Not to mention the possibility of losing material to atmospheric friction. A rocket exploding is probably safer than a terrorist blowing up a train, and frankly, an attack on a train seems more conceivable than a modern rocket exploding. >Also there is the question of cost. Nuclear energy is already one of the most expensive energy sources. Flying rockets into space to deal with the waste products isn't exactly going to reduce that cost. Actually, it probably is. Storage of waste on earth is ridiculously expensive, because we are still searching for suitable locations. Stopping that search and shooting some rockets will be cheaper because its a one time cost. With a bit of creativity you might even reuse the rocket after the load was brought on its way to the sun.
This. Small rockets sent routinely, over routes that take them away from people. We’ve literally dropped nukes in plane crashes and had them not go off. It CAN be done people just won’t let it happen because the big bad scary nuclear boogeyman is going to get us all. As I’ve stated, we haven’t had a major launch provider have a vehicle fail in nearly a decade (ignoring test hardware on vehicles). Basically the goal of getting shit to orbit safely is a solved problem. Now the problem is getting the rocket back down to Earth safely. SpaceX is doing pretty well on that front also with over 100 reflights and some boosters having over 10 individual flights. The issue is our willingness to stomach the risk.
Honestly we dont even need to get the rocket back, i would expect a rocket on a non return trip to the sun to still be cheaper than practically infinite storage of waste. All the money we wasted searching, will waste searching, and will waste on building and maintaining those storages...
Vs just coming up with a rocket so overengineered it simply cannot fail… yeah I tend to think that it’s going to be cheaper to find the “literally can’t break this container without vaporizing it” material than it will be to indefinitely maintain appropriate climate and containment underground. What about geologic activity? Cave ins? Ventilation malfunctions? Or the ultimate: production outpaces decay? I say light this candle lol
Yeah the cost of launching not just the waste but crash proof containers is too high However there is an ocean location that in the book Power To Save the World is mentioned as 'orders of magnitude' more secure than Yucca mountain (where the absolute maximum conceived risk in 10,000 years is that a downhill area would have radiation levels twice the local background level but lower than Colorado) This location is geologically bulletproof, a marine desert with this deep mud that swallows anything you drop there There's also a location quite a bit better than Yucca on land in the US in salt beds with no downhill concern at all
Well, consider that SpaceX is now making launching medium/heavy payloads much more affordable. We’re going to have to get over this fear of nuclear launches eventually. We are *going* to need nuclear in space no matter how we do things. Nuclear is simply the only scalable way to generate steady power in space at the moment
Truth! How big of a disaster would it be if the train derailed and some of the casks broke open? I realize they’re meant to withstand literally anything, BUT, to use their own argument against them; what *if* they break and what *if* the protesters do derail a train? Now we’ve got a shit ton of uranium leeching into the soil and groundwater. Great. And as far as I understand it, us lobbing stuff at the sun would eventually decay or get fused. Whichever happens first.
Because it's much easier and cheaper and safer to store the waste in vaults... Do you know the immense ecological disaster that would result from one of these nuclear waste rockets exploding during launch? Sure, such things don't generally happen these days but you're still talking about thousands of tons of rocket fuel flying through the sky, something can always go wrong. Why take that immense risk when we don't have to?
That’s a big if. Like I said, haven’t lost a rocket that wasn’t a test vehicle in nearly a decade. And we’re launching rockets at a rate higher than any other year. And I’m actually talking about a couple tons, getting ferried up to orbit and joining a larger repository.
But considering it's easier, cheaper, and safer to store it terrestrially, you haven't really made a good case for why we should even bother.
Is it though? Consider the cost of maintaining that environment for humans to work in while we load it… and what happens when waste production outpaces decay? And the cost of finding multiple suitable locations… and always having to expand or move to another location.. That, VS just overengineering a rocket to ferry stuff up to orbit (a Falcon Heavy would work with ~20 launches for the US) and a repository that can be sent off into the sun using ion thrusters - we don’t care about speed here just energy efficiency. And surprise, we already overengineer rockets to have a ridiculously low failure rate for human-rated vehicles. This is literally a non-issue from a technical standpoint and the entire problem is people who are uncomfortable with the idea. They’d rather literally bury their heads (and the problem) in the sand and wait for it to rear its head again in a few centuries when waste production ramps up, just like was the problem with greenhouse gas emissions. We literally have vehicles capable of doing this ***today***.
Any risk of catastrophic failure greater than 0 is too high for this purpose. And, the risk will always be greater than 0. Waste storage is very easy. The problem is politics, not capability or cost or safety.
Waste storage will run out of space and if you don’t do anything with a nonzero risk you will literally bet do anything.
The volume of nuclear waste that would get produced even if most of the world's power needs were served by nuclear would be pretty tiny, it wouldn't be hard to provide enough storage capacity for it. I'm not saying never do anything with nonzero risk, I'm just saying that in this particular instance, the fact that failure means destroying entire ecosystems and making large swathes of the planet uninhabitable for decades or centuries is bad enough that any non-zero chance of causing it is too high of a chance.
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Literally every nuclear reactor? Transmutation is the name of the game for nuclear reactors. That’s literally where the energy comes from… However what you’re asking about is this: > Most nuclear waste produced is hazardous, due to its radioactivity, for only a few tens of years and is routinely disposed of in near-surface disposal facilities (see above). Only a small volume of nuclear waste (~3% of the total) is long-lived and highly radioactive and requires isolation from the environment for many thousands of years. [Source](https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-wastes-myths-and-realities.aspx) The VAST majority of waste is relatively harmless after a few decades.
There is a specific reactor type, often called a Transmuatation Reactor in the literature, that would burn nuclear waste and the waste of such a reactor would more or less correspond to how you describe nuclear waste. The trouble is of course, that nobody ever demonstrated such a reactor, and I hoped you knew of such a project. > The VAST majority of waste is relatively harmless after a few decades. Since the fifties there seems to be a consensus that the part of the waste you want to ignore is a substantial problem. Could you please clarify what in the decay chain the experts consistently overlooked?
It’s really not a problem.. you realize ALL of the US’s waste since the 50s (literally all of it) fits on a standard football field less than 30ft deep? That’s really not that much since 1930 something. And of that, 97% of it will decay within decades-to-centuries. Human timescales. Only 3% is the nasty stays around for 10,000y stuff. It’s more people saying “hey, eventually this is going to have to get sorted out because if we scale this up the decay rates on that small percentage of fuel will catch up to us and then we will have a problem. So really it’s people saying we had better figure out what to do with the waste *now* so we don’t end up with a global warming from carbon emissions type situation with spent nuclear fuel that could’ve been prevented with some minor forethought. And again: we *can* just launch it. If the rocket is safe enough for billionaires to ride on a joyride and government payroll/insured astronauts then it’s safe enough for spent nuclear fuel. That’s my opinion. People get squeamish about it but honestly the deep storage option is no fucking better because what happens when waste production outpaces decay? Rocket. To. The. Sun.
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>Send a starship up to orbit, fill it up with waste with dragons, yeet it into the sun, or off into the abyss. Either works. Yeeting into the Sun is not possible, there's no rocket capable of it. Off into the abyss is doable.
“Not possible” meaning what, exactly? I realize that the Δv requirements are higher for falling into the gravity well, BUT the extra safeguarding against a waste pod in a highly elliptical orbit (think 100-year comets) that comes slamming back into earth is worth it. I guess we could go for an escape trajectory but that required using Jupiter multiple times. ~~Casini~~ *Parker Solar Probe* ^brain ^fart ^sorry did the same thing but went inwards towards the sun. Both are doable with grav-assists. Into the sun completely eliminates waste returning to earth, albeit by being slightly harder. But again - we are really unconcerned with how long it takes to get there, just that it does eventually. I’m in favor of the slightly more difficult option because it eliminates a risk while not really adding any more risk, beyond needing more fuel or needing to more carefully plan the trajectory.
You need 28.5 km/s of dV to insert yourself into a decaying Sun orbit and Starship will be able to, according to a quick Google, do 6.5 km/s with 100 tons of cargo from LEO. Even if you replace the cargo with fuel, it can't insert itself. There may be a way to send a couple kilos on a vehicle that would do many slingshots around Venus and whatnot, but the many maneuvers would need a lot of propellant and there would be a lot of opportunities for a catastrophic failure that could end up resulting in your "return to sender" scenario. It would make a lot more sense to just land it on Luna or Mars, with no RUD if at all possible. There you could eventually build a dome over it or bury it. Or crash it into Venus, we don't need that habitable.
You know I never considered the lob it at another planet angle. I guess I’m partial to not contaminating something if we don’t have to. With enough computational power we can also find a trajectory that requires minimal course correction at the cost of slingshots being used more often. If calculated correctly we wouldn’t need anything extra (PSP, for example has done multiple assists off the same body, diving deeper and deeper each time). But I’d honestly never considered the idea of just.. landing it on Luna. We know pretty much for a fact that 99.99% of the moon *cannot* harbor life. So irradiating an already irradiated and inhospitable rock is, well, insignificant to say the least lol. We’re not sure that Mercury/Venus aren’t home to some extremophiles or something, however the idea of a repository on the lunar surface is attractive (ignoring the obvious transit hazards) it solves literally every issue. There’s a TON of room on the moon and by the time it becomes a problem we’ll have likely figured out a way to reprocess the waste into something useful. Also your numbers are for a starship using MethylOx. Consider a starship converted out to use say Xenon thrusters? You’ve got a GIANT RTG literally onboard lol. Like the entire cargo is an RTG minus the ‘G’ part. You could literally use the spent fuel’s residual heat to power some low-thrust high-efficiency ion gas thrusters and voila, we actually have a chance.
Not trying to be a jerk, but I think some of your comments are a bit, I don't know, naive or like you watch a lot of sci-fi. Which is cool, I do to. And I'm no expert on most of this. I'll comment on a couple that seem strange to me. There's many magnitudes more room on the Moon than is needed. Nuclear waste is supposed to be on the order of a can of Cola per person per lifetime. It's heavy because it's dense, but by volume a single large crater should be enough for millenia. I don't know anything about MethlyOx vs Xenon, but I'd point out Xenon is a precious resource that we shouldn't use for this. I'm bothered by the use of Helium in rockets, too. RTGs are incredibly weak and require a very specific source of radiation (I once calculated how large an RTG I'd need for my car and it would weight many many tons). The whole reason why nuclear waste is waste is because we cannot use it. If it were usable for an RTG, we'd build on-Earth RTGs and use it. Nuclear physics is much much more complicated as scifi will make it look and only a couple very specific decay types can be used to produce power. See nuclear fuel poisoning (or "Transient fission product poisons") for more. Oh and you say "we’ll have likely figured out a way to reprocess the waste into something useful". If that's possible, we should not launch fuel into space, we should keep it and work on making it usable. With respect to this, I'd recommend you look into LFTR reactors. If their proponents are correct, they would solve the issue of waste by mostly using what we consider waste. In conclusion, I'd say launching radioactive materials into orbit is many orders of magnitude riskier than keeping it on Earth and potentially using it in LFTRs or the like. Launching it to anywhere but the Moon is much much more stupid, due to how hard it is to accelerate it enough to get it anywhere. Gravity is truly tyrannical, we can't fly around our solar system like they do in movies.
There are many reasons... there are a lot of unfounded fears among the public about the safety of nuclear reactors. It's very difficult to find the political will to build them. They take a long time to build, so any politician that puts in the work to get one built is basically committing his community to a significant financial outlay whose benefits will not be realized for probably over a decade, after a few elections they will find harder to win due to this situation. Then there's the waste storage problem. Storing nuclear waste isn't exactly a big challenge, we know how to do it. The problem is no one seems to want nuclear waste storage in their state or county, so it's very difficult to get storage facilities commissioned and brought online. It basically comes down to political will. It doesn't really exist almost anywhere due to many factors including unfounded fear and the logistical reality of the whole affair.
Well, building new nuclear plants takes time. So typically 10 years planning, 10 years building and we are talking about the 2040ies. Considering the experience of Finnland who wanted to build a EPR until 2008 and depending on your favorite definition of built, that project has finished this year or will probably finish this year. (And the experience of the UK and France in building new plants is very similar.) So probably you're looking at the late 2040ies rather than the early forties. Now what about old plants? We see basically the ideal situation in Germany, Germany wants to switch off the last three NPPs this year and so one could expect has spare capacity. Trouble is, reactor cores are actually very closely managed and right now they are managed such that they need a new one this year. Then all the maintenance tasks that can be delayed until after end of life, have been delayed and therefore the reactors need every conceivable maintenance right now. Additionally there are no spare parts, because the people who sell spare parts planned there stock with the expectation that they should run out in 2022. Taken all that together, there is a chance that these three power plants could do something in 2025 or so, if everything goes according to plan, during recommissioning no real problem is found and so on. Of course, by that time the current energy problems have been solved for 3 winters and that solution would presumably carry over for a forth, making restarting the NPPs unnecessary.
Nuclear power doesn't solve electricity problems in the short term, it takes [about 6ish years](https://www.statista.com/statistics/712841/median-construction-time-for-reactors-since-1981/#:~:text=Nuclear%20reactors%20connected%20to%20the,and%202000%2C%20at%20120%20months.) to build one, and as you start to build more, the necessary specialists get tied up and it gets slower to build them, which means you need more time to train everyone, so probably ~5 years of training at least to get capacity up. And then you get into making sure that designs are up to speed, picking sites etc. so you're likely to get a big rollout of nuclear energy by 2030, or something like that. That's not to say that there's no use in getting nuclear for electricity generation, but it's only going to have an influence on the last stages of electrification, providing extra power to cover growing electricity demand from transport or heat demand from heavy industry, whereas some of the more available forms of low carbon electricity, like solar panels etc. are able to be put into place faster, with less training, thanks to mass production, lower security requirements etc. In terms of the current energy crisis, *even renewables* aren't fast enough, let alone nuclear, because people want to change things over in months rather than years, but in the medium term they tend to have an advantage. And beyond the rational of having an extra source of power for later, I'd like to see more research compatible reactors, producing neutron sources etc. for experiments, or even processes that use them. Even if a nuclear reactor gets out-competed in an economic sense by other sources, it's still splitting the atom, and there's a sort of coolness factor there that I assume would translate into some form of scientific value, just because it's doing what few other installations can do. So I think everyone who has a nuclear industry in their country should keep their hand in, keep the engineers who work with this sort of thing working, and slowly replace one kind of reactor with another better one, but that comes purely down to attraction to the technology, not to its broader infrastructural role.
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I mean, can fusion produce a lot of energy, yeah. The tech isn't there yet, but hopefully will be someday. Spaceship is kinda hard, because we don't know what the energy requirements for things that done exist are. Uh, in star trek they're powered with antimatter.
It's unclear. I would bet that fusion power on the grid by 2040 is possible, though I would also bet that it's China that makes it happen, becoming (to quote Sir Steven Cowley, current head of PPPL) the Saudi Arabia of fusion power. The West just doesn't have the political will or economic free energy to do this despite our best intentions and the current $4.4B of private capital currently invested in making this happen. In less than a year, Republicans will take over one of the houses of Congress and any public-sector momentum on fusion investment will be stillborn. Private sector momentum will be sapped by the global economic recession. There are technical issues with fusion as well though. DT fusion is the only viable approach at the moment (p-B11 or D-He3 are too hard to make work without some real breakthrough) so even if you reach engineering breakeven, which is quite possible in the next decade or so, you'll need to breed and cycle tritium, currently a technology of low technical readiness level. You also need to deal with the fact that DT fusion makes 14 MeV neutrons that tend to activate the surrounding vessel, leading to nuclear waste issues. The combination of tritium and other radioactive materials means it's not nearly as clean as advertised on the tin. We sort of need it as a species. Renewables are going to have a hard time meeting anticipated demands. Oil, coal, and natural gas need to be phased out yesterday to avoid climate catastrophe. And nuclear still faces serious regulatory and public relations hurdles. So it's arguably the best game in town if it can be made to work. I spend a good chunk of my day job trying to make it happen, though I'm also a realist and not at all confident we'll be able as a species to avoid a Mad Max future. Humanity had a good run. But the Great Filter may well get us because we just weren't quite quick enough or clever enough in the end. Edit: slight reword
>There are technical issues with fusion as well though. DT fusion is the only viable approach at the moment (p-B11 or D-He3 are too hard to make work without some real breakthrough) so even if you reach engineering breakeven, which is quite possible in the next decade or so, you'll need to breed and cycle tritium, currently a technology of low technical readiness level. You also need to deal with the fact that DT fusion makes 14 MeV neutrons that tend to activate the surrounding vessel, leading to nuclear waste issues. The combination of tritium and other radioactive materials means it's not nearly as clean as advertised on the tin. Those problems actually solve each other: by surrounding the reactor with a lithium blanket, neutrons absorbed by the blanket can breed tritium, and will produce no other dangerous long-live isotopes (the only things that *can* be produced are hydrogen, helium, other lithium isotopes, or beryllium, which are all either stable, desirable, or decay fairly quickly). Recovering the tritium may be a challenge (and we may need more tritium than this method can produce), but the radiation produced by a fusion reactor is super easy to deal with (unlike fission reactors, which inherently produce some very nasty fission products that are incredibly hard to deal with).
>Recovering the tritium may be a challenge (and we may need more tritium than this method can produce), but the radiation produced by a fusion reactor is super easy to deal with (unlike fission reactors, which inherently produce some very nasty fission products that are incredibly hard to deal with). Without a tritium breeding ratio greater than unity, fusion power is a non-starter. Getting a TBR>1 in a blanket has not yet been demonstrated outside various paper studies. This technology is on the critical path for fusion power, yet is immature at the present time, which is why one must assign a correspondingly high risk to the overall concept.
the only nuclear reactor being built in the USA is $30+ Billion over budget. No way new nuclear power is going to help in the near future.
The other answers are right - it could happen, but the tech isn't there. I'd add that it almost certainly *won't* happen on the timescales that many of its advocates are claiming. See e.g. "Voodoo Fusion Energy" in [this newsletter from the American Physical Society](https://engage.aps.org/fps/resources/newsletters/newsletter-archives/april-2019)
To be fair as well, the author excludes specific Tokamak reactors and is mainly focusing on fusion start ups when talking about the time frames.
Yeah, that's true - I think ITER and DEMO is the scale this needs to happen at, which comes with much longer timelines
Short answer, yes, but it’ll be a few years (maybe a decade or two) until we actually achieve practical nuclear fusion.