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I honestly don't understand why there's so much focus on fusion. It's an inferior method of producing energy - extremely fussy, still produces nuclear waste, st

I honestly don't understand why there's so much focus on fusion. It's an inferior method of producing energy - extremely fussy, still produces nuclear waste, still capable of producing nuclear weapons material, and has yet to deliver a net surplus of energy[1]. When I was younger I never saw a peep about the nuclear waste and nuclear proliferation problems with fusion - it was just pitched as this miracle technology that was ten years away. I was really excited about it, but the more I learn about fusion the more it appears to be a giant money bonfire. We'd be better off just coming up with good fast breeder reactor designs that have good safety measures. A breeder reactor can burn its fuel completely, it's a tried and true technology and it's our best shot at eliminating fossil fuels. The fusion research is important science, and I completely support researching it, but it's not a technology that's going to be commercially useful in our lifetimes and it's not better or cleaner technology than modern fission reactor designs. [1] https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the...

k__ 5y ago
Shouldn't (at least) the USA have enough sub tropical geography for solar panels?
- mullingitover 5y ago
  We definitely do! However the rate that solar can be added is nowhere near fast enough to replace fossil fuels in a timeframe that meets our climate goals and prevents environmental catastrophe[1]. > Solar and wind power alone can’t scale up fast enough to generate the vast amounts of electricity that will be needed by midcentury, especially as we convert car engines and the like from fossil fuels to carbon-free energy sources. Even Germany’s concerted recent effort to add renewables—the most ambitious national effort so far—was nowhere near fast enough. A global increase in renewables at a rate matching Germany’s peak success would add about 0.7 trillion kilowatt-hours of clean electricity every year. That’s just over a fifth of the necessary 3.3 trillion annual target. > To put it another way, even if the world were as enthusiastic and technically capable as Germany at the height of its renewables buildup—and neither of these is even close to true in the great majority of countries—decarbonizing the world at that rate would take nearly 150 years. [1] https://www.wsj.com/articles/only-nuclear-energy-can-save-the-planet-11547225861 https://www.wsj.com/articles/only-nuclear-energy-can-save-th...
  - westoncb 5y ago
    > However the rate that solar can be added is nowhere near fast enough ... Any idea what the bottleneck(s) is/are?
    - 7952 5y ago
      In the UK substation capacity is a constraint. Rural connection points tend to have limited capacity to export to the wider grid.
  - 7952 5y ago
    It seems unfair to compare a hypothetical nuclear build rate to a real one in renewables. We just don't know if a nuclear industry could get anywhere near the deployment rate required.
    - mullingitover 5y ago
      You're right, and I'm not saying we should slow down on solar, but based on the numbers, solar alone is not going to get us where we need to be, so we should be pushing the nuclear industry to find out how fast they can deploy and bulldozing a path for them while we also push for faster deployment of solar.
  - jodrellblank 5y ago
    Between 2010 and 2019 the UK added 10GW of onshore wind generating capacity, 8.5GW of offshore wind generating capacity, roughly 13GW of solar capacity, and 0 nuclear plants. The UK has not brought a new (commercial/public power) nuclear reactor online since the nineties, or finished building a completely new site since the eighties. It has started building one, which is over budget and delayed and has been described as “the most expensive power station in the world”. It has had three recent plans cancelled, four more go nowhere in years, had two developers (EON and nPower) pull out of UK nuclear, and the Scottish parliament had backed no new nuclear plants in Scotland. If nuclear is our saviour, it’s not looking very likely that we’ll be saved.
- thehappypm 5y ago
  You don't even need sub tropical. Massachusetts, in the Northeast, is showing a real-world strategy for solar. Massachusetts incentivizes homeowners to have their own solar installs. My house, for example, has solar, as do many houses in my town. Yesterday it produced about 50 kWh, meaning I was sending energy into the grid. You might ask, what's the point of solar if there's no storage? Going 100% renewable would be amazing, but reducing CO2 is a win. If electric load declines because more and more homes can produce their own electric, that's a huge reduction in total CO2 that needs to be produced at the power plants. It doesn't mean we can throw away the gas plants, but they can be run at lower capacity. Storage isn't really discussed yet, but maybe one day we'll get there. We're also investing in a huge offshore wind farm.
a1371 5y ago
It's a pretty big logical jump to say fusion has proliferation problem because it creates a neutron stream. It will be as if they build the Hadron collider to warm up soup. It's unrelated to the plant operation, unlike fission. I think this highlights the bias in the article you shared. Moreover, it solely focuses on ITER which is not a great example any more. Fusion doesn't really have the problems of fission. Because fusion has been extremely underfunded, the money is being spent extra carefully on ITER. But MIT SPARC is using new super conductors to get much smaller reactors. Reactors will produce some low level waste, but once we get a handle of the confinement, that issue can be eliminated with hydrogen isotope mixes. Also, Tokamak is only one fusion design, there may be better ways to capture the neutron stream.
- mullingitover 5y ago
  These are all valid points, and I'm not saying we shouldn't do research on fusion. It certainly has promise. However, I don't think it has a serious chance of pulling a deus ex machina move and saving us from climate change in our lifetimes. A solid energy source a century from now? Sure. Fission on the other hand has a good chance of uprooting the fossil fuel industry, and combined with other renewables is our best chance of getting carbon emissions to a place where civilization might not go into a bronze age-style collapse from climate change.
  - willis936 5y ago
    As an industry insider: everyone knows this. Fusion isn't the technology that saves mankind in this century, but it is the technology that mankind needs to have working by the next century if we want to stay on our current industrial track. The march of progress might halt if we run out of ever-increasing access to free energy.
jkelleyrtp 5y ago
> 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.
MisterTea 5y ago
> still produces nuclear waste, Yes but you only have to worry about radioactive reactor parts and other structural materials, not spent fuel. > still capable of producing nuclear weapons material, I don't get this argument at all. A fusion reactor does not generate heavy elements such as uranium or plutonium. However, the fusion reaction can be a neutron source which could be used to convert heavy elements such as thorium or uranium into fissile material. But by no means would this be part of any power generation station. This leads us to... > We'd be better off just coming up with good fast breeder reactor designs So this neutron source is somehow more clean and secure than the other one you just dismissed?
fastball 5y ago
Working on fusion doesn't mean we're not working on better fission. We should do both. I think both fusion/fission are great but your comment is misleading at best. - Fusion produces much less radioactive waste byproducts then fission. It's not zero, but it's a significant difference. - The problems with nuclear weapons proliferation are much easier to handle with fusion. For starters, you're not transporting enriched uranium fuel around. Also you don't end up with fun transuranics like plutonium which can be readily used to make weapons, unlike any key byproducts of fusion. Hell, the main byproduct of our fusion reactors is gonna be Helium, which we actually need more of because it is a very useful element that experiences shortages due to not being contained in the atmosphere and not being super prevalent in the earth's crust. - "Extremely fussy" is a selling point. Extremely fussy means that if something goes wrong you don't have a runaway chain reaction that makes everything go boom. It's impossible to design a fusion reactor that can melt down. Meanwhile, melting down is the default mode for fission reactors and needs to be carefully designed around. - Fusion is the only viable energy source for long-term space travel/colonization. - The point about net energy surplus is kinda nonsensical. Of course we're not there yet, that's why it's a problem we're actively working on and not something we've already solved. Your point is literally "we shouldn't develop this technology because we haven't developed this technology yet". Also not sure how we can simultaneously need to "come up" with a good fast breeder reactor design while at the same time it's apparently "tried and true technology".
- mullingitover 5y ago
  > - "Extremely fussy" is a selling point. Extremely fussy means that if something goes wrong you don't have a runaway chain reaction that makes everything go boom. Sorry, I should've elaborated a bit on this point. I'm talking about the expensive containment system which will be subject to extreme conditions and have a short lifetime[1]. > Under reactor-relevant conditions, the following are the most serious damaging mechanisms: thermally induced defects such as cracking and melting of the plasma-facing material (PFM); thermal fatigue damage of the joints between the PFM and the heat sink; hydrogen-induced blistering; helium-generated formation of nanosized clusters; and neutron-induced degradation of the wall armor via reduction of the thermal conductivity, embrittlement, transmutation, and activation. > Further serious lifetime-limiting PWI processes are caused by material irradiation with hydrogen isotope ions (D+ and T+) and impurities that—depending on their impact energy—will sputter the wall material. The eroded species will be deposited elsewhere, for example, on unshielded parts of the vacuum vessel, on blanket modules, or on less severely exposed divertor targets (outside the separatrix strike zone). Implantation of hydrogen isotopes into the surface of the PFM will result in severe embrittlement of the wall. This also has a strong impact on its cracking resistance, in particular during short transient thermal loads (i.e., ELMs). Helium will also be implanted into the surface of the wall armor or buried in redeposited surface layers. Implanted helium tends to migrate (depending on the prevailing temperature) and to form tiny bubbles that again can interact with implanted hydrogen. In several fusion-relevant PFMs (e.g., tungsten) helium can initiate rather substantial changes in surface morphology, such as the growth of tiny tendrils or “fuzz” on the surface of the PFM.12 These layers can easily reach several micrometers in thickness. These effects need to be considered as a potential source for the release of dust particles and contamination of the burning fusion plasma. So I'm not talking about the fail-safe nature but rather the extreme cost and technical difficulty of containing the reaction for the amount of time that would be needed for fusion to be a viable commercial energy source. [1] https://aip.scitation.org/doi/10.1063/1.5090100 https://aip.scitation.org/doi/10.1063/1.5090100

k__ 5y ago

Shouldn't (at least) the USA have enough sub tropical geography for solar panels?

mullingitover 5y ago
We definitely do! However the rate that solar can be added is nowhere near fast enough to replace fossil fuels in a timeframe that meets our climate goals and prevents environmental catastrophe[1]. > Solar and wind power alone can’t scale up fast enough to generate the vast amounts of electricity that will be needed by midcentury, especially as we convert car engines and the like from fossil fuels to carbon-free energy sources. Even Germany’s concerted recent effort to add renewables—the most ambitious national effort so far—was nowhere near fast enough. A global increase in renewables at a rate matching Germany’s peak success would add about 0.7 trillion kilowatt-hours of clean electricity every year. That’s just over a fifth of the necessary 3.3 trillion annual target. > To put it another way, even if the world were as enthusiastic and technically capable as Germany at the height of its renewables buildup—and neither of these is even close to true in the great majority of countries—decarbonizing the world at that rate would take nearly 150 years. [1] https://www.wsj.com/articles/only-nuclear-energy-can-save-the-planet-11547225861 https://www.wsj.com/articles/only-nuclear-energy-can-save-th...
- westoncb 5y ago
  > However the rate that solar can be added is nowhere near fast enough ... Any idea what the bottleneck(s) is/are?
  - 7952 5y ago
    In the UK substation capacity is a constraint. Rural connection points tend to have limited capacity to export to the wider grid.
- 7952 5y ago
  It seems unfair to compare a hypothetical nuclear build rate to a real one in renewables. We just don't know if a nuclear industry could get anywhere near the deployment rate required.
  - mullingitover 5y ago
    You're right, and I'm not saying we should slow down on solar, but based on the numbers, solar alone is not going to get us where we need to be, so we should be pushing the nuclear industry to find out how fast they can deploy and bulldozing a path for them while we also push for faster deployment of solar.
- jodrellblank 5y ago
  Between 2010 and 2019 the UK added 10GW of onshore wind generating capacity, 8.5GW of offshore wind generating capacity, roughly 13GW of solar capacity, and 0 nuclear plants. The UK has not brought a new (commercial/public power) nuclear reactor online since the nineties, or finished building a completely new site since the eighties. It has started building one, which is over budget and delayed and has been described as “the most expensive power station in the world”. It has had three recent plans cancelled, four more go nowhere in years, had two developers (EON and nPower) pull out of UK nuclear, and the Scottish parliament had backed no new nuclear plants in Scotland. If nuclear is our saviour, it’s not looking very likely that we’ll be saved.
thehappypm 5y ago
You don't even need sub tropical. Massachusetts, in the Northeast, is showing a real-world strategy for solar. Massachusetts incentivizes homeowners to have their own solar installs. My house, for example, has solar, as do many houses in my town. Yesterday it produced about 50 kWh, meaning I was sending energy into the grid. You might ask, what's the point of solar if there's no storage? Going 100% renewable would be amazing, but reducing CO2 is a win. If electric load declines because more and more homes can produce their own electric, that's a huge reduction in total CO2 that needs to be produced at the power plants. It doesn't mean we can throw away the gas plants, but they can be run at lower capacity. Storage isn't really discussed yet, but maybe one day we'll get there. We're also investing in a huge offshore wind farm.

a1371 5y ago

It's a pretty big logical jump to say fusion has proliferation problem because it creates a neutron stream. It will be as if they build the Hadron collider to warm up soup. It's unrelated to the plant operation, unlike fission. I think this highlights the bias in the article you shared. Moreover, it solely focuses on ITER which is not a great example any more. Fusion doesn't really have the problems of fission. Because fusion has been extremely underfunded, the money is being spent extra carefully on ITER. But MIT SPARC is using new super conductors to get much smaller reactors. Reactors will produce some low level waste, but once we get a handle of the confinement, that issue can be eliminated with hydrogen isotope mixes. Also, Tokamak is only one fusion design, there may be better ways to capture the neutron stream.

mullingitover 5y ago
These are all valid points, and I'm not saying we shouldn't do research on fusion. It certainly has promise. However, I don't think it has a serious chance of pulling a deus ex machina move and saving us from climate change in our lifetimes. A solid energy source a century from now? Sure. Fission on the other hand has a good chance of uprooting the fossil fuel industry, and combined with other renewables is our best chance of getting carbon emissions to a place where civilization might not go into a bronze age-style collapse from climate change.
- willis936 5y ago
  As an industry insider: everyone knows this. Fusion isn't the technology that saves mankind in this century, but it is the technology that mankind needs to have working by the next century if we want to stay on our current industrial track. The march of progress might halt if we run out of ever-increasing access to free energy.

jkelleyrtp 5y ago

> 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.

MisterTea 5y ago

> still produces nuclear waste, Yes but you only have to worry about radioactive reactor parts and other structural materials, not spent fuel. > still capable of producing nuclear weapons material, I don't get this argument at all. A fusion reactor does not generate heavy elements such as uranium or plutonium. However, the fusion reaction can be a neutron source which could be used to convert heavy elements such as thorium or uranium into fissile material. But by no means would this be part of any power generation station. This leads us to... > We'd be better off just coming up with good fast breeder reactor designs So this neutron source is somehow more clean and secure than the other one you just dismissed?

fastball 5y ago

Working on fusion doesn't mean we're not working on better fission. We should do both. I think both fusion/fission are great but your comment is misleading at best. - Fusion produces much less radioactive waste byproducts then fission. It's not zero, but it's a significant difference. - The problems with nuclear weapons proliferation are much easier to handle with fusion. For starters, you're not transporting enriched uranium fuel around. Also you don't end up with fun transuranics like plutonium which can be readily used to make weapons, unlike any key byproducts of fusion. Hell, the main byproduct of our fusion reactors is gonna be Helium, which we actually need more of because it is a very useful element that experiences shortages due to not being contained in the atmosphere and not being super prevalent in the earth's crust. - "Extremely fussy" is a selling point. Extremely fussy means that if something goes wrong you don't have a runaway chain reaction that makes everything go boom. It's impossible to design a fusion reactor that can melt down. Meanwhile, melting down is the default mode for fission reactors and needs to be carefully designed around. - Fusion is the only viable energy source for long-term space travel/colonization. - The point about net energy surplus is kinda nonsensical. Of course we're not there yet, that's why it's a problem we're actively working on and not something we've already solved. Your point is literally "we shouldn't develop this technology because we haven't developed this technology yet". Also not sure how we can simultaneously need to "come up" with a good fast breeder reactor design while at the same time it's apparently "tried and true technology".

mullingitover 5y ago
> - "Extremely fussy" is a selling point. Extremely fussy means that if something goes wrong you don't have a runaway chain reaction that makes everything go boom. Sorry, I should've elaborated a bit on this point. I'm talking about the expensive containment system which will be subject to extreme conditions and have a short lifetime[1]. > Under reactor-relevant conditions, the following are the most serious damaging mechanisms: thermally induced defects such as cracking and melting of the plasma-facing material (PFM); thermal fatigue damage of the joints between the PFM and the heat sink; hydrogen-induced blistering; helium-generated formation of nanosized clusters; and neutron-induced degradation of the wall armor via reduction of the thermal conductivity, embrittlement, transmutation, and activation. > Further serious lifetime-limiting PWI processes are caused by material irradiation with hydrogen isotope ions (D+ and T+) and impurities that—depending on their impact energy—will sputter the wall material. The eroded species will be deposited elsewhere, for example, on unshielded parts of the vacuum vessel, on blanket modules, or on less severely exposed divertor targets (outside the separatrix strike zone). Implantation of hydrogen isotopes into the surface of the PFM will result in severe embrittlement of the wall. This also has a strong impact on its cracking resistance, in particular during short transient thermal loads (i.e., ELMs). Helium will also be implanted into the surface of the wall armor or buried in redeposited surface layers. Implanted helium tends to migrate (depending on the prevailing temperature) and to form tiny bubbles that again can interact with implanted hydrogen. In several fusion-relevant PFMs (e.g., tungsten) helium can initiate rather substantial changes in surface morphology, such as the growth of tiny tendrils or “fuzz” on the surface of the PFM.12 These layers can easily reach several micrometers in thickness. These effects need to be considered as a potential source for the release of dust particles and contamination of the burning fusion plasma. So I'm not talking about the fail-safe nature but rather the extreme cost and technical difficulty of containing the reaction for the amount of time that would be needed for fusion to be a viable commercial energy source. [1] https://aip.scitation.org/doi/10.1063/1.5090100 https://aip.scitation.org/doi/10.1063/1.5090100