57 ms·

They listed 5 challenges but they forgot probably the biggest one-- Make it cheaper than the alternatives. That might never happen even if we do solve all the m

by aqme28 2y ago

They listed 5 challenges but they forgot probably the biggest one-- Make it cheaper than the alternatives. That might never happen even if we do solve all the material and technical problems. Disclaimer-- I did my masters on fusion reactor simulations.

acidburnNSA 2y ago
Fully agreed. It took us from 1944 to 1965 in fission to go from "ok it makes net energy" to "ok we can make electricity on the commercial market within the realm of the existing alternatives". Fusion is still pre-1944 in that they haven't even demonstrated getting net energy out, let alone put together an electricity-generating machine. I have no doubt at all that we'll make fusion-derived electricity in my lifetime. But I have no idea whether or not we'll make it cheap. They say the fuel is cheap. It's not (tritium and He-3 are hard to come by), but even if it were, keep in mind that a fleet of uranium-fueled fission reactors like the one in France spends about 5-10% of its costs on fuel.
- ajross 2y ago
  "Within the realm" involves some externalities though. Fission reactors have never been particularly cost competitive with other electrical generation technologies. They were subsidized heavily because people wanted reactors to build bombs, and more broadly to cultivate a technology base of people who could build and maintain reactors to build bombs. Once we had enough bombs, that subsidy got rolled back and fission fell off the leaderboard.
  - acidburnNSA 2y ago
    If you spend as much time reading the early 1950s documentation of the nuclear industry, you'll quickly see that commercial nuclear reactor development was very much decoupled from the graphite or heavy-water moderated bomb-making reactors. They separated around 1953 and never came back together. Back then, the fledgling industry was wondering if they could sell excess plutonium for bombs, but the government said that they were not interested in buying it. They said they had more than enough coming from their own specialized bomb-making reactors. Certainly nuclear tech was subsidized originally by the Manhattan project, but very soon after, bomb making and nuclear power went their separate ways. You could much more strongly argue that the nuclear reactor development made to power submarines helped develop the commercial nuclear power industry. This checks out much more cleanly, as Shippingport was led by Rickover himself.
    - jillesvangurp 2y ago
      That is a bit revisionist. Most of the investment went towards reactor technology and research that had a dual purpose of generating power but also being aligned with generating plutonium. That's why the type of reactors used in nuclear sub marines was never commercialized. Simply too expensive for civilian use and they never had a dual use that benefited generating material for nuclear bombs. Commercial reactors today are based on minor variations of nuclear fission that was also strategically relevant for getting plutonium. Different reactors but same mineral supply chains and a lot of overlap in R&D. As soon as the cold war ran to an end, funding for all that fell off a cliff. Including building new nuclear power plants. Coal and gas plants were vastly cheaper to build. And they still are. And back then, nobody cared about pollution. Only now that people are interested in small reactors are these decades old fission reactors getting more attention.
      - PaulHoule 2y ago
        The PWR used for power [1] is to first order "the same type of reactor used in submarines" in the sense that it is a thermal (in terms of neutron spectrum) reactor which is cooled by pressurized water. The submarine reactor uses highly enriched uranium and, I believe, burns like a cigarette, which makes it easy to start and stop the reactor without worrying about [2]. It doesn't produce a lot of Plutonium because it doesn't have much U238 in it. I believe the fuel elements are horizontally oriented. It's built tough because it might get knocked around in a war. The commercial reactor has vertically oriented fuel elements and tries to burn the fuel uniformly along the axis because this minimizes cost, because minimizing cost is a matter of maximizing power for a certain sized reactor core, and maximizing power is a matter of maximizing heat transfer out of the interior of the fuel rod and to the coolant, so you want to be producing and removing heat from the whole volume of the core. Temporal uniformity helps with spatial uniformity so the reactor is not so good at starting and stopping, but it can follow loads [3] Notably the west (where natural gas is available) quit building coal burning power plants at the same time it quit building nuclear power plants, partially because of pollution [4], partially because a 100% steam turbine powerset as used in coal and nuclear plants can't compete with a gas-fired combined cycle powerplant which combines a very-low capital cost gas turbine with a steam turbine that is about half the size (and cost) The small LWR is a pipe dream because LWR economics improve as the reactor gets bigger. One reason why we can't build reactors on an N-th of a kind basis is that every time we build one we decide the economics weren't that good and they might get better if we scale the design up. Had NuScale ever built a plant they probably would have tried scaling it up too. It is claimed small reactors could be easier to build but until somebody actually builds one, this claim is hard to take seriously. One path that makes sense is to pick an optimized design for a large reactor and "get good" at building it, it could be an advanced Western design like the AP1000 or something like the Chinese Hualong One which is an improved version of the reactors that France built in the glory days. The Russians are really good at building the VVER, their version of the PWR. The other path is to build a reactor that works at much higher temperatures such as the fast breeder reactor, high temperature gas cooled reactor, or molten salt reactor and couple it to a gas turbine powerset or use the heat to produce hydrogen directly. [5] This is still decades away. [1] Pressurized Water Reactor, there is also a Boiling Water Reactor in which the water boils in the core but it's not a vast difference: these are both called LWRs (Light Water Reactor) [2] https://en.wikipedia.org/wiki/Xenon-135 https://en.wikipedia.org/wiki/Xenon-135 [3] https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... [4] https://en.wikipedia.org/wiki/Acid_rain https://en.wikipedia.org/wiki/Acid_rain (SO2 from coal burning plants, ironically, masked the warming effects of CO2 until we cleaned up coal plants) [5] https://en.wikipedia.org/wiki/Generation_IV_reactor https://en.wikipedia.org/wiki/Generation_IV_reactor
  - actionfromafar 2y ago
    From first principles, ignoring safety (which was pretty lacklustre in the beginning) fission should be cheap though.
    - wqaatwt 2y ago
      To be fair people were fine with multiple Chernobyl’s amount of damage every years from burning coal. And other disasters like Three Miles Island very insignificant.
      - pbronez 2y ago
        > multiple Chernobyl’s amount of damage every years from burning coal. Do you have a source for that? I'd be very interested in a study that quantifies the damage of coal plants in terms of famous nuclear disasters.
        actionfromafar 2y ago
        Fly-ash contains radionuclides.
        pfdietz 2y ago
        However, 99% of fly ash is captured in electrostatic precipitators and filters. Calculations that include the radionuclides in the captured ash are not being honest.
        actionfromafar 2y ago
        Yes now, but not back when fission plants were first brought online.
        pfdietz 2y ago
        But we can ask: if this is the important issue justifying nuclear, which is more cost effective: adding pollution control to coal plants, or building nuclear plants? If it's not the important issue justifying nuclear over coal, why bring it up?
  - wqaatwt 2y ago
    Had that continued we’d be halfway to solving climate change by now, though. Of course “environmentalists” and most others back in those days preferred cheaper coal and gas.
    - roenxi 2y ago
      The irony is how consistently the environmentalists have been campaigning for things that left the environment worse by delaying any possible transition to nuclear power.
    - ajross 2y ago
      Renewables are already 30% of world energy generation and growing rapidly: a quick google says that 86% (!!!) of new capacity is renewable. This part of the climate puzzle is effectively already solved, and didn't need nuclear. Transport fuel and combustion-based heavy industry are the hard nuts to crack, and reactors don't help there.
      - wqaatwt 2y ago
        We’re are just late by several decades…
  - Y_Y 2y ago
    I'd note that the externalities may change that calculus a bit. The relative pollution from coal/gas/oil are huge but the cost isn't reflected in the price at the meter.
- natmaka 2y ago
  Breeding is a counter-example. Fermi envisioned it in the early 1940's. Lab breeder reactors emerged during the 1950's and were satisfying in the 1960's. Big projects aiming at obtaining an industrial reactor were aplenty, worldwide, during the 1970's through the 1990's. They all failed, and remaining efforts are quite sparse. https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reactors https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reacto... Obtaining something adequate (raw size, reliability, safety, ease of use...) isn't always easy. The quest of an industrial nuclear fusion reactor may tank this way.
  - pfdietz 2y ago
    Breeding is a great analogy to fusion. In fact, the original government interest in fusion was for using DD fusion to make neutrons to breed plutonium (DD fusion doesn't need to use the neutrons to breed tritium).
short_sells_poo 2y ago
I'm not an expert, but I actually feel like it's not terrestrial power generation where fusion would be useful. We have plenty of ways of generating power here, including a massive fusion reactor up in the sky which will continue operating for the foreseeable future :) Instead, I think need to find some way of generating a lot of power over extended periods of time if we want to crack space travel beyond lobbing items into Earth orbit. Particularly for human space travel. We need significantly more energy density than what chemical motors can provide, and nuclear is the easiest and most "within-reach" that we know of. Things like anti-matter and even more exotic forms of propulsion are pure sci-fi for the time being (in terms of practicality). I suppose fission could work in a very primitive way of basically detonating small nukes behind a pusher plate, but fusion feels so much more elegant (at least to a layman). Mostly in the sense of not having to use effectively the same nukes we stick in weapons. Something tells me that this will never fly (excuse the pun), for obvious reasons.
- notahacker 2y ago
  Near-earth space has an abundance of solar energy convertible to electrical energy. Deep space is an interesting potential use case for fusion, but fission-powered electric space propulsion via RTGs has the virtue of having demonstrated nearly half a century of continuous operation (and after it leaves the earth's atmosphere, radioactivity ceases to be a concern)
  - pfdietz 2y ago
    As far as I know there has never been an RTG powered electric rocket engine. RTGs are extremely expensive per unit of power output. Spacecraft like that ion engine propelled one that was sent to Ceres use solar power.
    - notahacker 2y ago
      Voyager and Pioneer used RTGs, as well as some more recent longer range missions and the planned Dragonfly to Titan. Agree that solar has much better unit economics, but I don't see any reason why the same wouldn't be true of fusion too.
kragen 2y ago
Yesterday, after wanting it for years, I finally found what looks like a good reference on what makes power plants so expensive. Most fusion-power proposals are based on using the fusion reactor to provide heat for a conventional thermal electrical power plant; https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost... gives a couple hundred pages of details about why those are expensive. As I said in my comment at the time https://news.ycombinator.com/item?id=42850472 https://news.ycombinator.com/item?id=42850472, the cost of solar panels has dropped in recent years to the point where it's dramatically cheaper to generate electricity with solar than from a thermal power plant.
- jodrellblank 2y ago
  https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-need-a-lot-of-solar-panels/ https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-... is a proposal to generate solar (and wind?) power and use it to make synthetic 'natural gas' as the long term energy storage for when the wind is calm and the sunlight blocked. That can go into existing gas storage and pipelines, and be used to drive existing gas power stations.
  - kragen 2y ago
    Yes, hydrocarbons have major advantages as a form of seasonal energy storage, and possibly you can burn them in cheaper, less efficient power plants. Round-trip efficiency is inevitably going to be pretty low with electrically generated fuels, but they still ought to be able to outcompete fossil fuels economically once production scales up. Gas has the advantage that gas turbines are less inefficient than conventional steam, though ultra-supercritical steam (mentioned in the EIA paper) could conceivably take that away, and of course it's easier to ship around over short distances.
    - tomsto 2y ago
      Hydrocarbons are great for energy density, but gas turbines are brilliant for power density. That's why we need them (and syn fuels)
pfdietz 2y ago
The significant issue is that DT fusion reactors are very large compared to fission reactors. If we look at gross nuclear power output per unit volume, comparing a fusion reactor to a PWR primary reactor vessel, the comparison is stark. ITER, for example, has a power density 400x worse than a PWR; the 2014 ARC design is 40x worse. This large size has devastating implications. The nuclear island of a fission power plant is maybe 12% of the cost of the plant. Increase that cost by an order of magnitude and you've doubled the cost of the plant. Commercial nuclear power is already not competitive; double the capex and it becomes ludicrously uncompetitive. If someone presents you a fusion proposal, the first thing you should ask is "what's the volumetric power density of your reactor?" If you look at the arguments purporting to show DT fusion could have a chance they do things like assume they can build everything for 2x the cost of materials. Yeah, good luck with that, especially when that cost estimation technique would give wildly low results if you applied it to fission power plants, which are much less complex. As I see it, there's only a couple of ways fusion might make it. The first is an approach that makes minimizing reactor size the primary goal. This would involve very small plasma configurations and one where all plasma-facing surfaces are covered with thick layers of flowing liquid lithium so areal power density can be very high, at least an order of magnitude higher than most concepts. Among DT efforts, only Zap looks like it might have a chance here (but there are parts on one end of the reactor that are still exposed to neutrons, unshielded.) The experience with liquid sodium in fission reactors should give one pause about making this work, though. The other approach would be to avoid non-nuclear parts than fission power plants have by exploiting direct conversion of plasma energy to work, so the apples-to-apples comparison of heat sources does not apply. Helion is the front runner here, using more advanced fuels that put most of their energy into the plasma, not into neutrons. I consider Helion the least dubious of all current fusion efforts.
ndsipa_pomu 2y ago
Absolutely. Even if fusion reactors can be made reliable, they'll still require a huge amount of investment with a payoff decades into the future. Meanwhile, you buy some cheap solar panels and can get returns on your money almost immediately.
- aqme28 2y ago
  Yes. Laypeople often forget about this fact. A big reason that we're not building fission plants is because you won't get anything back for a decade or more. And by that time, will it still even be competitive?
jillesvangurp 2y ago
This, it's mostly an economic challenge. We need clean energy that is cheap. Not clean energy that is more expensive. It's important for clean energy to be cheap because that creates an economic incentive for people to invest in switching. The good news with renewable energy and battery storage is that we're basically there. Texas which produces lots of oil also produces lots of clean energy. Because oil refineries require a lot of energy to refine their fuel. And of course using your own product at a premium when clean renewables do the same job would be madness. Think about it, the very companies that are expecting others to buy and burn their fossil fuel are investing (heavily) in renewable energy because that's cheaper than using their own cheap supply of oil and gas for the same purpose. It's more lucrative to sell that than to use it for them. That's why records are being broken with amounts of solar, wind, and battery coming online on a regular basis. It's cheaper. So, people do more of it as fast as they can scrape the funding together to do it. Fusion if it happens at all is probably going to be really expensive for quite some time. Nuclear has the same problem. Clean but just super expensive. And slow to plan and execute. You need to decide decades in advance that you need it in order to have it ready. Most reactors coming online this year (hint: not a lot) were planned when solar and wind were still expensive (1-2 decades ago). In other words, they probably did not take into account current price levels of new clean energy. In terms of profitability these things are kind of dead on arrival. Fusion faces the exact same challenges. It's not completely hopeless. But we need 1-2 orders of magnitude reduction of cost per energy generated this way.
- baq 2y ago
  > This, it's mostly an economic challenge. We need clean energy that is cheap. Not clean energy that is more expensive. Cheap and expensive in dollar terms is meaningless. Dollars are numbers in computers. Joules and watts are real. What I can agree with we need good enough EROI energy and then adjust the policies regarding fusion, nuclear and fossil joules, watts and their related numbers in computers.
  - jillesvangurp 2y ago
    You are right with the policy shift. But I would suggest to stop throwing good money after bad money instead until the sector massively improves its accuracy of numbers it does publish on such things like budgets and timelines for new projects. Because most of the numbers coming out of the nuclear sector for this are too good to be true. To put it mildly. It's tempting to use more harsh language here. Like "fabricated nonsense" or "a scam". And some people do. Probably the biggest challenge for nuclear proponents aside from demonstrably high cost, overruns, wildly optimistic timelines, etc. for past projects is the credibility of their predictions about cost for future ones. The lower those predictions, the smaller the chance that those are anything more than wishful thinking mixed with a lot of hopium and based on very flawed assumptions. When cost overruns in nuclear projects are routinely measured in hundreds of percents, something is very wrong. It would be nice to get that down to two digit percentages. That would still be terrible but a lot better than the industry norms for this. Especially compared to renewable projects. This credibility challenge is a large part of the reluctance of investors to fund new efforts in this space. Most of the projects that actually still happen feature governments and tax payers taking most of the risk. Which makes it more likely that the huge budget gaps get funded rather than resulting in investors cutting their losses and bailing. If you want numbers, look at numbers of GW coming online for nuclear, wind, solar, and energy storage projects. There's a stark difference there. Renewables are outpacing nuclear at such a pace that you could legitimately wonder why to bother with such projects at all.
ksec 2y ago
> Make it cheaper than the alternatives. I wish SMR gets more attentions and focus. The UK has more Wind resources to power all four nations and it is on course to double its current 30% electricity from Wind to 60% by ~2030. I dont see why it cant be 90%+ by 2040 barring policy, politics and human factors. All we need then are SMRs for base loads, while we work on energy storage that could be battery or Dams.
- ViewTrick1002 2y ago
  SMRs have been complete vaporware for the past 70 years. https://spectrum.ieee.org/the-forgotten-history-of-small-nuclear-reactors https://spectrum.ieee.org/the-forgotten-history-of-small-nuc... Or just this recent summary on how all modern SMRs tend to show promising PowerPoints and then cancel when reality hits. https://www.youtube.com/watch?v=XECq9uFsy6o https://www.youtube.com/watch?v=XECq9uFsy6o Simply look to: - mPower: https://en.wikipedia.org/wiki/B%26W_mPower https://en.wikipedia.org/wiki/B%26W_mPower - NuScale: https://oregoncapitalchronicle.com/2024/10/29/the-rise-and-fall-of-nuscale-a-nuclear-cautionary-tale/ https://oregoncapitalchronicle.com/2024/10/29/the-rise-and-f... And the rest of the bunch adding costs for every passing year and then disappearing when the subsidies run out. Not sure why you would want to fill storage with extremely expensive nuclear power when we might as well just use cheap renewables.
  - ksec 2y ago
    GE Hitachi’s small modular reactor (SMR) provides 24/7 on-demand, carbon-free power. https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300-small-modular-reactor https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300...
    - ViewTrick1002 2y ago
      Which is wholly irrelevant if the costs are so high that no one will buy the power. Which is especially true considering how renewables and storage is plummeting in cost seeing incredible growth.
amelius 2y ago
> They listed 5 challenges but they forgot probably the biggest one-- Make it cheaper than the alternatives. Does it really need to be cheaper if it's more promising?
- jacknews 2y ago
  promising what? It needs to promise to eventually be cheaper, or otherwise better in some niche. I can imagine it being useful for spaceships, for example. But I can't see it ever being cheaper than eg solar, without some kind of breakthrough, like cold-fusion.

by aqme28 2y ago

acidburnNSA 2y ago

Fully agreed. It took us from 1944 to 1965 in fission to go from "ok it makes net energy" to "ok we can make electricity on the commercial market within the realm of the existing alternatives". Fusion is still pre-1944 in that they haven't even demonstrated getting net energy out, let alone put together an electricity-generating machine. I have no doubt at all that we'll make fusion-derived electricity in my lifetime. But I have no idea whether or not we'll make it cheap. They say the fuel is cheap. It's not (tritium and He-3 are hard to come by), but even if it were, keep in mind that a fleet of uranium-fueled fission reactors like the one in France spends about 5-10% of its costs on fuel.

ajross 2y ago
"Within the realm" involves some externalities though. Fission reactors have never been particularly cost competitive with other electrical generation technologies. They were subsidized heavily because people wanted reactors to build bombs, and more broadly to cultivate a technology base of people who could build and maintain reactors to build bombs. Once we had enough bombs, that subsidy got rolled back and fission fell off the leaderboard.
- acidburnNSA 2y ago
  If you spend as much time reading the early 1950s documentation of the nuclear industry, you'll quickly see that commercial nuclear reactor development was very much decoupled from the graphite or heavy-water moderated bomb-making reactors. They separated around 1953 and never came back together. Back then, the fledgling industry was wondering if they could sell excess plutonium for bombs, but the government said that they were not interested in buying it. They said they had more than enough coming from their own specialized bomb-making reactors. Certainly nuclear tech was subsidized originally by the Manhattan project, but very soon after, bomb making and nuclear power went their separate ways. You could much more strongly argue that the nuclear reactor development made to power submarines helped develop the commercial nuclear power industry. This checks out much more cleanly, as Shippingport was led by Rickover himself.
  - jillesvangurp 2y ago
    That is a bit revisionist. Most of the investment went towards reactor technology and research that had a dual purpose of generating power but also being aligned with generating plutonium. That's why the type of reactors used in nuclear sub marines was never commercialized. Simply too expensive for civilian use and they never had a dual use that benefited generating material for nuclear bombs. Commercial reactors today are based on minor variations of nuclear fission that was also strategically relevant for getting plutonium. Different reactors but same mineral supply chains and a lot of overlap in R&D. As soon as the cold war ran to an end, funding for all that fell off a cliff. Including building new nuclear power plants. Coal and gas plants were vastly cheaper to build. And they still are. And back then, nobody cared about pollution. Only now that people are interested in small reactors are these decades old fission reactors getting more attention.
    - PaulHoule 2y ago
      The PWR used for power [1] is to first order "the same type of reactor used in submarines" in the sense that it is a thermal (in terms of neutron spectrum) reactor which is cooled by pressurized water. The submarine reactor uses highly enriched uranium and, I believe, burns like a cigarette, which makes it easy to start and stop the reactor without worrying about [2]. It doesn't produce a lot of Plutonium because it doesn't have much U238 in it. I believe the fuel elements are horizontally oriented. It's built tough because it might get knocked around in a war. The commercial reactor has vertically oriented fuel elements and tries to burn the fuel uniformly along the axis because this minimizes cost, because minimizing cost is a matter of maximizing power for a certain sized reactor core, and maximizing power is a matter of maximizing heat transfer out of the interior of the fuel rod and to the coolant, so you want to be producing and removing heat from the whole volume of the core. Temporal uniformity helps with spatial uniformity so the reactor is not so good at starting and stopping, but it can follow loads [3] Notably the west (where natural gas is available) quit building coal burning power plants at the same time it quit building nuclear power plants, partially because of pollution [4], partially because a 100% steam turbine powerset as used in coal and nuclear plants can't compete with a gas-fired combined cycle powerplant which combines a very-low capital cost gas turbine with a steam turbine that is about half the size (and cost) The small LWR is a pipe dream because LWR economics improve as the reactor gets bigger. One reason why we can't build reactors on an N-th of a kind basis is that every time we build one we decide the economics weren't that good and they might get better if we scale the design up. Had NuScale ever built a plant they probably would have tried scaling it up too. It is claimed small reactors could be easier to build but until somebody actually builds one, this claim is hard to take seriously. One path that makes sense is to pick an optimized design for a large reactor and "get good" at building it, it could be an advanced Western design like the AP1000 or something like the Chinese Hualong One which is an improved version of the reactors that France built in the glory days. The Russians are really good at building the VVER, their version of the PWR. The other path is to build a reactor that works at much higher temperatures such as the fast breeder reactor, high temperature gas cooled reactor, or molten salt reactor and couple it to a gas turbine powerset or use the heat to produce hydrogen directly. [5] This is still decades away. [1] Pressurized Water Reactor, there is also a Boiling Water Reactor in which the water boils in the core but it's not a vast difference: these are both called LWRs (Light Water Reactor) [2] https://en.wikipedia.org/wiki/Xenon-135 https://en.wikipedia.org/wiki/Xenon-135 [3] https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... [4] https://en.wikipedia.org/wiki/Acid_rain https://en.wikipedia.org/wiki/Acid_rain (SO2 from coal burning plants, ironically, masked the warming effects of CO2 until we cleaned up coal plants) [5] https://en.wikipedia.org/wiki/Generation_IV_reactor https://en.wikipedia.org/wiki/Generation_IV_reactor
- actionfromafar 2y ago
  From first principles, ignoring safety (which was pretty lacklustre in the beginning) fission should be cheap though.
  - wqaatwt 2y ago
    To be fair people were fine with multiple Chernobyl’s amount of damage every years from burning coal. And other disasters like Three Miles Island very insignificant.
    - pbronez 2y ago
      > multiple Chernobyl’s amount of damage every years from burning coal. Do you have a source for that? I'd be very interested in a study that quantifies the damage of coal plants in terms of famous nuclear disasters.
      - actionfromafar 2y ago
        Fly-ash contains radionuclides.
        pfdietz 2y ago
        However, 99% of fly ash is captured in electrostatic precipitators and filters. Calculations that include the radionuclides in the captured ash are not being honest.
        actionfromafar 2y ago
        Yes now, but not back when fission plants were first brought online.
        pfdietz 2y ago
        But we can ask: if this is the important issue justifying nuclear, which is more cost effective: adding pollution control to coal plants, or building nuclear plants? If it's not the important issue justifying nuclear over coal, why bring it up?
- wqaatwt 2y ago
  Had that continued we’d be halfway to solving climate change by now, though. Of course “environmentalists” and most others back in those days preferred cheaper coal and gas.
  - roenxi 2y ago
    The irony is how consistently the environmentalists have been campaigning for things that left the environment worse by delaying any possible transition to nuclear power.
  - ajross 2y ago
    Renewables are already 30% of world energy generation and growing rapidly: a quick google says that 86% (!!!) of new capacity is renewable. This part of the climate puzzle is effectively already solved, and didn't need nuclear. Transport fuel and combustion-based heavy industry are the hard nuts to crack, and reactors don't help there.
    - wqaatwt 2y ago
      We’re are just late by several decades…
- Y_Y 2y ago
  I'd note that the externalities may change that calculus a bit. The relative pollution from coal/gas/oil are huge but the cost isn't reflected in the price at the meter.
natmaka 2y ago
Breeding is a counter-example. Fermi envisioned it in the early 1940's. Lab breeder reactors emerged during the 1950's and were satisfying in the 1960's. Big projects aiming at obtaining an industrial reactor were aplenty, worldwide, during the 1970's through the 1990's. They all failed, and remaining efforts are quite sparse. https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reactors https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reacto... Obtaining something adequate (raw size, reliability, safety, ease of use...) isn't always easy. The quest of an industrial nuclear fusion reactor may tank this way.
- pfdietz 2y ago
  Breeding is a great analogy to fusion. In fact, the original government interest in fusion was for using DD fusion to make neutrons to breed plutonium (DD fusion doesn't need to use the neutrons to breed tritium).

short_sells_poo 2y ago

I'm not an expert, but I actually feel like it's not terrestrial power generation where fusion would be useful. We have plenty of ways of generating power here, including a massive fusion reactor up in the sky which will continue operating for the foreseeable future :) Instead, I think need to find some way of generating a lot of power over extended periods of time if we want to crack space travel beyond lobbing items into Earth orbit. Particularly for human space travel. We need significantly more energy density than what chemical motors can provide, and nuclear is the easiest and most "within-reach" that we know of. Things like anti-matter and even more exotic forms of propulsion are pure sci-fi for the time being (in terms of practicality). I suppose fission could work in a very primitive way of basically detonating small nukes behind a pusher plate, but fusion feels so much more elegant (at least to a layman). Mostly in the sense of not having to use effectively the same nukes we stick in weapons. Something tells me that this will never fly (excuse the pun), for obvious reasons.

notahacker 2y ago
Near-earth space has an abundance of solar energy convertible to electrical energy. Deep space is an interesting potential use case for fusion, but fission-powered electric space propulsion via RTGs has the virtue of having demonstrated nearly half a century of continuous operation (and after it leaves the earth's atmosphere, radioactivity ceases to be a concern)
- pfdietz 2y ago
  As far as I know there has never been an RTG powered electric rocket engine. RTGs are extremely expensive per unit of power output. Spacecraft like that ion engine propelled one that was sent to Ceres use solar power.
  - notahacker 2y ago
    Voyager and Pioneer used RTGs, as well as some more recent longer range missions and the planned Dragonfly to Titan. Agree that solar has much better unit economics, but I don't see any reason why the same wouldn't be true of fusion too.

kragen 2y ago

Yesterday, after wanting it for years, I finally found what looks like a good reference on what makes power plants so expensive. Most fusion-power proposals are based on using the fusion reactor to provide heat for a conventional thermal electrical power plant; https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost... gives a couple hundred pages of details about why those are expensive. As I said in my comment at the time https://news.ycombinator.com/item?id=42850472 https://news.ycombinator.com/item?id=42850472, the cost of solar panels has dropped in recent years to the point where it's dramatically cheaper to generate electricity with solar than from a thermal power plant.

jodrellblank 2y ago
https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-need-a-lot-of-solar-panels/ https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-... is a proposal to generate solar (and wind?) power and use it to make synthetic 'natural gas' as the long term energy storage for when the wind is calm and the sunlight blocked. That can go into existing gas storage and pipelines, and be used to drive existing gas power stations.
- kragen 2y ago
  Yes, hydrocarbons have major advantages as a form of seasonal energy storage, and possibly you can burn them in cheaper, less efficient power plants. Round-trip efficiency is inevitably going to be pretty low with electrically generated fuels, but they still ought to be able to outcompete fossil fuels economically once production scales up. Gas has the advantage that gas turbines are less inefficient than conventional steam, though ultra-supercritical steam (mentioned in the EIA paper) could conceivably take that away, and of course it's easier to ship around over short distances.
  - tomsto 2y ago
    Hydrocarbons are great for energy density, but gas turbines are brilliant for power density. That's why we need them (and syn fuels)

pfdietz 2y ago

The significant issue is that DT fusion reactors are very large compared to fission reactors. If we look at gross nuclear power output per unit volume, comparing a fusion reactor to a PWR primary reactor vessel, the comparison is stark. ITER, for example, has a power density 400x worse than a PWR; the 2014 ARC design is 40x worse. This large size has devastating implications. The nuclear island of a fission power plant is maybe 12% of the cost of the plant. Increase that cost by an order of magnitude and you've doubled the cost of the plant. Commercial nuclear power is already not competitive; double the capex and it becomes ludicrously uncompetitive. If someone presents you a fusion proposal, the first thing you should ask is "what's the volumetric power density of your reactor?" If you look at the arguments purporting to show DT fusion could have a chance they do things like assume they can build everything for 2x the cost of materials. Yeah, good luck with that, especially when that cost estimation technique would give wildly low results if you applied it to fission power plants, which are much less complex. As I see it, there's only a couple of ways fusion might make it. The first is an approach that makes minimizing reactor size the primary goal. This would involve very small plasma configurations and one where all plasma-facing surfaces are covered with thick layers of flowing liquid lithium so areal power density can be very high, at least an order of magnitude higher than most concepts. Among DT efforts, only Zap looks like it might have a chance here (but there are parts on one end of the reactor that are still exposed to neutrons, unshielded.) The experience with liquid sodium in fission reactors should give one pause about making this work, though. The other approach would be to avoid non-nuclear parts than fission power plants have by exploiting direct conversion of plasma energy to work, so the apples-to-apples comparison of heat sources does not apply. Helion is the front runner here, using more advanced fuels that put most of their energy into the plasma, not into neutrons. I consider Helion the least dubious of all current fusion efforts.

ndsipa_pomu 2y ago

Absolutely. Even if fusion reactors can be made reliable, they'll still require a huge amount of investment with a payoff decades into the future. Meanwhile, you buy some cheap solar panels and can get returns on your money almost immediately.

aqme28 2y ago
Yes. Laypeople often forget about this fact. A big reason that we're not building fission plants is because you won't get anything back for a decade or more. And by that time, will it still even be competitive?

jillesvangurp 2y ago

This, it's mostly an economic challenge. We need clean energy that is cheap. Not clean energy that is more expensive. It's important for clean energy to be cheap because that creates an economic incentive for people to invest in switching. The good news with renewable energy and battery storage is that we're basically there. Texas which produces lots of oil also produces lots of clean energy. Because oil refineries require a lot of energy to refine their fuel. And of course using your own product at a premium when clean renewables do the same job would be madness. Think about it, the very companies that are expecting others to buy and burn their fossil fuel are investing (heavily) in renewable energy because that's cheaper than using their own cheap supply of oil and gas for the same purpose. It's more lucrative to sell that than to use it for them. That's why records are being broken with amounts of solar, wind, and battery coming online on a regular basis. It's cheaper. So, people do more of it as fast as they can scrape the funding together to do it. Fusion if it happens at all is probably going to be really expensive for quite some time. Nuclear has the same problem. Clean but just super expensive. And slow to plan and execute. You need to decide decades in advance that you need it in order to have it ready. Most reactors coming online this year (hint: not a lot) were planned when solar and wind were still expensive (1-2 decades ago). In other words, they probably did not take into account current price levels of new clean energy. In terms of profitability these things are kind of dead on arrival. Fusion faces the exact same challenges. It's not completely hopeless. But we need 1-2 orders of magnitude reduction of cost per energy generated this way.

baq 2y ago
> This, it's mostly an economic challenge. We need clean energy that is cheap. Not clean energy that is more expensive. Cheap and expensive in dollar terms is meaningless. Dollars are numbers in computers. Joules and watts are real. What I can agree with we need good enough EROI energy and then adjust the policies regarding fusion, nuclear and fossil joules, watts and their related numbers in computers.
- jillesvangurp 2y ago
  You are right with the policy shift. But I would suggest to stop throwing good money after bad money instead until the sector massively improves its accuracy of numbers it does publish on such things like budgets and timelines for new projects. Because most of the numbers coming out of the nuclear sector for this are too good to be true. To put it mildly. It's tempting to use more harsh language here. Like "fabricated nonsense" or "a scam". And some people do. Probably the biggest challenge for nuclear proponents aside from demonstrably high cost, overruns, wildly optimistic timelines, etc. for past projects is the credibility of their predictions about cost for future ones. The lower those predictions, the smaller the chance that those are anything more than wishful thinking mixed with a lot of hopium and based on very flawed assumptions. When cost overruns in nuclear projects are routinely measured in hundreds of percents, something is very wrong. It would be nice to get that down to two digit percentages. That would still be terrible but a lot better than the industry norms for this. Especially compared to renewable projects. This credibility challenge is a large part of the reluctance of investors to fund new efforts in this space. Most of the projects that actually still happen feature governments and tax payers taking most of the risk. Which makes it more likely that the huge budget gaps get funded rather than resulting in investors cutting their losses and bailing. If you want numbers, look at numbers of GW coming online for nuclear, wind, solar, and energy storage projects. There's a stark difference there. Renewables are outpacing nuclear at such a pace that you could legitimately wonder why to bother with such projects at all.

ksec 2y ago

> Make it cheaper than the alternatives. I wish SMR gets more attentions and focus. The UK has more Wind resources to power all four nations and it is on course to double its current 30% electricity from Wind to 60% by ~2030. I dont see why it cant be 90%+ by 2040 barring policy, politics and human factors. All we need then are SMRs for base loads, while we work on energy storage that could be battery or Dams.

ViewTrick1002 2y ago
SMRs have been complete vaporware for the past 70 years. https://spectrum.ieee.org/the-forgotten-history-of-small-nuclear-reactors https://spectrum.ieee.org/the-forgotten-history-of-small-nuc... Or just this recent summary on how all modern SMRs tend to show promising PowerPoints and then cancel when reality hits. https://www.youtube.com/watch?v=XECq9uFsy6o https://www.youtube.com/watch?v=XECq9uFsy6o Simply look to: - mPower: https://en.wikipedia.org/wiki/B%26W_mPower https://en.wikipedia.org/wiki/B%26W_mPower - NuScale: https://oregoncapitalchronicle.com/2024/10/29/the-rise-and-fall-of-nuscale-a-nuclear-cautionary-tale/ https://oregoncapitalchronicle.com/2024/10/29/the-rise-and-f... And the rest of the bunch adding costs for every passing year and then disappearing when the subsidies run out. Not sure why you would want to fill storage with extremely expensive nuclear power when we might as well just use cheap renewables.
- ksec 2y ago
  GE Hitachi’s small modular reactor (SMR) provides 24/7 on-demand, carbon-free power. https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300-small-modular-reactor https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300...
  - ViewTrick1002 2y ago
    Which is wholly irrelevant if the costs are so high that no one will buy the power. Which is especially true considering how renewables and storage is plummeting in cost seeing incredible growth.

amelius 2y ago

> They listed 5 challenges but they forgot probably the biggest one-- Make it cheaper than the alternatives. Does it really need to be cheaper if it's more promising?

jacknews 2y ago
promising what? It needs to promise to eventually be cheaper, or otherwise better in some niche. I can imagine it being useful for spaceships, for example. But I can't see it ever being cheaper than eg solar, without some kind of breakthrough, like cold-fusion.