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> nuclear proliferation problems with fusion We already have fusion bombs. Building fusion reactors wouldn't impact nuclear proliferation at all. I really can'

> nuclear proliferation problems with fusion We already have fusion bombs. Building fusion reactors wouldn't impact nuclear proliferation at all. I really can't think of a single fusion reactor design that produces "nuclear weapons material." If fusion designs made nuclear material, then we'd probably already have nuclear-material-producing fusion reactors. I find it strange that you think breeder reactors are the way to go. Fusion's challenges are rooted in engineering - creating magnetic fields, heating plasma, breeding tritium. Fission's challenges are in public sentiment, exuberant costs, and dealing with extremely toxic metals. > it's not better or cleaner technology than modern fission reactor designs The "nasty ingredients" in fusion are deuterium, tritium, lithium, and irradiated confinement metal (think eutectic materials like stainless steel). The "nasty ingredients" for fission are much, much worse - both in products and required inputs. Fusion promises energy generation without the high atomic count; this makes the inputs easier to acquire, the risk of catastrophe much lower, and allows more flexibility in design (scale, cost, efficiency targets).

mullingitover 5y ago
> Fission's challenges are in public sentiment, exuberant costs, and dealing with extremely toxic metals. I'd argue that a lot of the public sentiment problems with nuclear were PR'd into existence by the insanely powerful and wealthy fossil fuel industry to which fission is a very real existential threat. If we're talking about exuberant costs, fusion beats fusion hands down and has yet to deliver a single net watt of power. The waste disposal is more of a political problem than a technical one. Overall, the problems with fusion are hard technical problems, and the problems with fission are self-imposed political ones pushed by the fossil fuel extraction industry that fission could very realistically replace.
- heimdall 5y ago
  Unfortunately, we live in a world where public opinion (skewed by fossil fuel companies or otherwise) is a huge driving force. We can lament what the world would be like if only people were more knowledgeable, but at the end of the day it's the ecosystem we have to operate in. Fusion power has indeed had high R&D costs, but so has any significant project before the ROI starts to kick in. Fusion power (especially the types that don't generate a neutron flux) is safer and more productive in principle compared to fission, and I have high confidence I will live to see a commercial fusion reactor come online in my lifetime.
- Retric 5y ago
  While it would last a long time at current levels, the supply of fission materials is quite limited when you’re looking into interstellar travel etc. That’s really the promise of fusion it’s an unimaginably vast energy source for the future. As to more sort term concerns, fission has a lot of very expensive requirements like 24/7/365 security which make it difficult to integrate with vastly cheaper renewables. Baseline power sources like nuclear and coal wind are at a massive disadvantage when integrating with significantly cheaper wind and solar. They lose significant amounts of money during part of the day and need much higher premiums the rest of the day to make up for it. In today’s energy market there is definitely a place for fission. However, with a 50 year payback period you need to project into future energy markers with even cheaper solar, wind, and batteries. That’s why electricity companies generally view it as a dead end. Fusion is a larger unknown, it’s probably not going to be cost effective but it’s also the kind of long shot that might just pay off.
  - jabl 5y ago
    > the supply of fission materials is quite limited when you’re looking into interstellar travel etc Yeah, sure, if we're gonna get a big spaceship to even a small fraction of light speed, that would require absolutely stupendous amounts of energy. But lets worry about that after we avoid cooking ourselves with GHG emissions? We might or might not have enough fission fuel for large-scale interstellar travel, but certainly more than enough to get rid of fossil fuels. > fission has a lot of very expensive requirements like 24/7/365 security So will fusion, unfortunately, unless someone figures out aneutronic fusion, which is a much longer shot than D-T fusion most efforts are concentrating on. I'm all for spending a lot more on fusion R&D though; the potential win is just so enormously large that it makes sense to bet some amount of resources on it, just in case it works out.
jabl 5y ago
> Building fusion reactors wouldn't impact nuclear proliferation at all. I really can't think of a single fusion reactor design that produces "nuclear weapons material." Since a fusion reactor would produce an intense neutron field, it doesn't take a genius to figure out that if you line the reactor vessel with natural uranium, you have a device for producing plutonium. That is by no means a showstopper, but it means fusion plants will need 24/7 security, IAEA inspections, worries when/if suspicious tinpot dictator states decide that they will need their own fusion power plants, etc. etc. Even if we'd magically solve the technical challenges in fusion, we won't be seeing things like dinky fusion-powered ships sailing around the oceans (for larger ships, one could envision some kind of IAEA monitoring system for those). Of course, if someone figures out aneutronic fusion (pB11 or such), these proliferation concerns would evaporate. That's a pretty big if, though. > dealing with extremely toxic metals. Spent fuel, in particular, is certainly radiotoxic, but chemically, no, not that big of a worry. Society routinely deals with other toxic heavy metals like lead as well, not to mention all kinds of other extremely toxic compounds.
- jkelleyrtp 5y ago
  Fusion power plants are certainly not the only thing we have that makes neutrons. You can buy neutron sources suitable for irradiating fissile material without having to build a fusion power plant. Fusion power plants would also be a terrible place to irradiate uranium. Getting material in and out would be a total hassle and you wouldn't necessarily be able to control the reaction.

mullingitover 5y ago

> Fission's challenges are in public sentiment, exuberant costs, and dealing with extremely toxic metals. I'd argue that a lot of the public sentiment problems with nuclear were PR'd into existence by the insanely powerful and wealthy fossil fuel industry to which fission is a very real existential threat. If we're talking about exuberant costs, fusion beats fusion hands down and has yet to deliver a single net watt of power. The waste disposal is more of a political problem than a technical one. Overall, the problems with fusion are hard technical problems, and the problems with fission are self-imposed political ones pushed by the fossil fuel extraction industry that fission could very realistically replace.

heimdall 5y ago
Unfortunately, we live in a world where public opinion (skewed by fossil fuel companies or otherwise) is a huge driving force. We can lament what the world would be like if only people were more knowledgeable, but at the end of the day it's the ecosystem we have to operate in. Fusion power has indeed had high R&D costs, but so has any significant project before the ROI starts to kick in. Fusion power (especially the types that don't generate a neutron flux) is safer and more productive in principle compared to fission, and I have high confidence I will live to see a commercial fusion reactor come online in my lifetime.
Retric 5y ago
While it would last a long time at current levels, the supply of fission materials is quite limited when you’re looking into interstellar travel etc. That’s really the promise of fusion it’s an unimaginably vast energy source for the future. As to more sort term concerns, fission has a lot of very expensive requirements like 24/7/365 security which make it difficult to integrate with vastly cheaper renewables. Baseline power sources like nuclear and coal wind are at a massive disadvantage when integrating with significantly cheaper wind and solar. They lose significant amounts of money during part of the day and need much higher premiums the rest of the day to make up for it. In today’s energy market there is definitely a place for fission. However, with a 50 year payback period you need to project into future energy markers with even cheaper solar, wind, and batteries. That’s why electricity companies generally view it as a dead end. Fusion is a larger unknown, it’s probably not going to be cost effective but it’s also the kind of long shot that might just pay off.
- jabl 5y ago
  > the supply of fission materials is quite limited when you’re looking into interstellar travel etc Yeah, sure, if we're gonna get a big spaceship to even a small fraction of light speed, that would require absolutely stupendous amounts of energy. But lets worry about that after we avoid cooking ourselves with GHG emissions? We might or might not have enough fission fuel for large-scale interstellar travel, but certainly more than enough to get rid of fossil fuels. > fission has a lot of very expensive requirements like 24/7/365 security So will fusion, unfortunately, unless someone figures out aneutronic fusion, which is a much longer shot than D-T fusion most efforts are concentrating on. I'm all for spending a lot more on fusion R&D though; the potential win is just so enormously large that it makes sense to bet some amount of resources on it, just in case it works out.

jabl 5y ago

> Building fusion reactors wouldn't impact nuclear proliferation at all. I really can't think of a single fusion reactor design that produces "nuclear weapons material." Since a fusion reactor would produce an intense neutron field, it doesn't take a genius to figure out that if you line the reactor vessel with natural uranium, you have a device for producing plutonium. That is by no means a showstopper, but it means fusion plants will need 24/7 security, IAEA inspections, worries when/if suspicious tinpot dictator states decide that they will need their own fusion power plants, etc. etc. Even if we'd magically solve the technical challenges in fusion, we won't be seeing things like dinky fusion-powered ships sailing around the oceans (for larger ships, one could envision some kind of IAEA monitoring system for those). Of course, if someone figures out aneutronic fusion (pB11 or such), these proliferation concerns would evaporate. That's a pretty big if, though. > dealing with extremely toxic metals. Spent fuel, in particular, is certainly radiotoxic, but chemically, no, not that big of a worry. Society routinely deals with other toxic heavy metals like lead as well, not to mention all kinds of other extremely toxic compounds.

jkelleyrtp 5y ago
Fusion power plants are certainly not the only thing we have that makes neutrons. You can buy neutron sources suitable for irradiating fissile material without having to build a fusion power plant. Fusion power plants would also be a terrible place to irradiate uranium. Getting material in and out would be a total hassle and you wouldn't necessarily be able to control the reaction.