12 ms·

While I don't really agree with the premise, my initial impression is that this should get ten upvotes for being so well reasoned and executed. Amazing work, I'

• pc86 11y ago
  I'm struggling to figure out why nuclear is lumped in with fossil fuels.
  • nostromo 11y ago
    Nuclear is low-carbon, but it's not renewable. Earth has a set amount of uranium that is destroyed when creating energy. Currently we have about 200 years of uranium available for economical extraction. But if we tried to replace all coal with nuclear, we would be out within a few decades. Then we'd need to move to other non-renewable materials (thorium?) or start mining astroids. http://www.scientificamerican.com/article/how-long-will-global-uranium-deposits-last/ http://www.scientificamerican.com/article/how-long-will-glob... And the mining of uranium looks awfully similar to the mining of coal. (Of course you need far fewer uranium mines for the same amount of energy.) https://en.wikipedia.org/wiki/Uranium_mining#/media/File:Arandis_Mine_quer.jpg https://en.wikipedia.org/wiki/Uranium_mining#/media/File:Ara...
    • burke 11y ago
      Is that a problem (the non-renewability)? Even if we deplete our available uranium while transitioning to fully renewable energy, we've still quit dumping carbon into the atmosphere. At that point, economic pressures are adequate to force us to renewable energy, I think.
    • danieltillett 11y ago
      Nuclear is not really low carbon when you take into account the amount of concrete you need to build a modern reactor. Unless we have a major breakthrough in mining uranium or we actually manage to make breeder reactors safe and cost effective then nuclear is not really a viable option. Edit. I should have been more precise in my language. By low carbon I am meaning minimal carbon, not just lower carbon. Natural gas is lower carbon, but it is not low carbon. It really doesn't matter too much because there just isn't enough uranium to make it a viable alternative at the scale we need to have a significant impact on carbon emissions.
      • XorNot 11y ago
        In the time honoured tradition of shooting ourselves in the foot by making better the enemy of best? Neither concrete, nor uranium mining have to burn fossil fuels (and CO2 sequesting concrete is a real thing). They are decoupled from their fuel source, but the lack of incentives to improve that situation at present (due to the near entirety of electrical generation being fossil fuels) is the bigger problem.
        • danieltillett 11y ago
          Making cement by its nature releases a large amount of CO2 and accounts for 5% of total emissions [1]. I do agree that we are not really creating the right incentives to improve things. 1. https://en.m.wikipedia.org/wiki/Environmental_impact_of_concrete https://en.m.wikipedia.org/wiki/Environmental_impact_of_conc...
          • XorNot 11y ago
            But note from that page: energy use is 40% of the CO2 expense of concrete. So assume we can pretty much eliminate that by other means. That leaves a 50% chunk due to chemistry. For that we have things like eco-cement, or carbon sequestration technologies.
          • vonmoltke 11y ago
            In addition to what XorNot7 said, the amount of concrete needed to build a nuclear power plant is trivial compared to the total amount consumed annually by the construction industry.
      • xigency 11y ago
        > Nuclear is not really low carbon when you take into account the amount of concrete you need to build a modern reactor. That sounds really preposterous.
      • DennisP 11y ago
        It's less than the concrete for an equivalent amount of wind power. Neither is all that significant compared to fossil fuels.
    • gnaritas 11y ago
      > Nuclear is low-carbon, but it's not renewable. Sure it is, Nuclear doesn't just mean uranium fission, fusion reactors are nuclear as well and they will be a big thing in the future and we get better at doing it.
      • nostromo 11y ago
        Just 20 more years now... ;-)
        • gnaritas 11y ago
          Progress takes time, but it is the future of energy.
      • NickM 11y ago
        > fusion reactors are nuclear as well and they will be a big thing in the future I used to think this as well, but I'm not sure I believe it anymore. I suspect that by the time we're able to make fusion power work, the solar/wind/batteries combo may be so cheap as to make fusion pointless for mainstream power generation.
        • gnaritas 11y ago
          Solar is fusion being mainstream :) however, smaller more local reactors will I think still be a huge part of our future as well.
    • jerf 11y ago
      Along with the fact uranium is not the only source of nuclear energy, "nonrenewables" that can supply current rates of consumption for thousands of years are effectively not "nonrenewable" in the sense we usually mean. Sure, it can't carry us to a Kardashev Type II civilization, but we're only responsible for the problems of today.
    • guscost 11y ago
      Sure, but the need to transition away from non-renewable energy is not the goal that Bret is working on (limiting anthropogenic CO2 and therefore its atmospheric concentration). I think everyone agrees there is a much longer "grace period" before those resources would be depleted than there is for even the slowest of hypothesized AGW scenarios. So if accelerating the depletion of uranium (ha) would solve the more pressing issue then it makes sense. Perhaps your concern is that people would get complacent with what can only be a temporary solution (even if temporary means thousands of years), but if AGW is regarded as an urgent and critical problem to solve, I don't think you can afford to ignore the opportunity. > Currently we have about 200 years of uranium available for economical extraction. In that 200 years a whole lot more uranium will become available for economical extraction, exactly the same as what happened with oil and natural gas.
    • merpnderp 11y ago
      Peak uranium is about as believable as peak oil. And given that uranium is a tiny fraction on the operating cost of a nuclear plant, it is viable at much higher prices. Which means much lower yield ores can be used for fuel. | And then there is thorium, which we have more of than we know what to do with. Then there's mining Uranium from the Ocean which puts a ceiling on the price of Uranium at 15x the current price. Economically unfeasible today, but it is the max it could ever cost. http://spectrum.ieee.org/energy/nuclear/nuclear-fuel-from-the-sea http://spectrum.ieee.org/energy/nuclear/nuclear-fuel-from-th...
      • superuser2 11y ago
        Why is peak oil not believable? There might be more of than we thought, but we're pretty sure there's not infinitely much. It has to happen eventually.
        • merpnderp 11y ago
          When I say peak oil isn't believable, I mean in the sense that over the last 15 years, especially before shale oil, the west was bombarded by "experts" saying peak oil had already occurred, and oil would be unafforadable in just a few years as prices skyrocketed. Any argument that involved technological progress in reducing the cost of mining hard to get oil was mocked and lambasted as hopelessly naive. I of course don't believe that there's an infinite supply of oil. Only that we haven't exhausted the millions of years of dead trees, which before the the emergence of white fungus with the ability to eat them, covered the Earth a hundred meters deep in some places.
          • crpatino 11y ago
            It is a fact that conventional oil has already peaked, sometime in the last 5-10 years. Shale oil, tar sands and the like are picking up part of the slack, though their EROI is lower (though still a little better than renewables) and have a bunch of other technical and environmental issues. At some point we'll have to bite that bullet. The problem with your remark was caused by the doomers who took the flag of Peak Oil (TM) to claim that everything was going to crash and burn when the peak reached. Then when reality turned out to be more nuanced than that, the general public just went on to laugh the whole thing off and keep ignoring the real issues. In an ideal world, we should be in the middle of a crahs program to retool the whole industry to work with renewables and mitigate the effects of other related issues like climate change/global weirding... but instead, we are doing too little and too late.
    • tomp 11y ago
      > Nuclear is low-carbon, but it's not renewable. So is the sun. But seriously, the amount of fissile fuel we have available greatly would suffice for hundreds of years of energy, and leave very little waste, if we only invested in nuclear technologies a bit more.
    • DennisP 11y ago
      From your first link: > Two technologies could greatly extend the uranium supply itself. Neither is economical now, but both could be in the future if the price of uranium increases substantially. First, the extraction of uranium from seawater would make available 4.5 billion metric tons of uranium—a 60,000-year supply at present rates. Second, fuel-recycling fast-breeder reactors, which generate more fuel than they consume, would use less than 1 percent of the uranium needed for current LWRs. Breeder reactors could match today's nuclear output for 30,000 years using only the NEA-estimated supplies. Unless we build a very large number of conventional reactors over the next couple decades, which isn't likely, we've got time to develop more advanced reactors.
    • ommunist 11y ago
      This reminds me of Mendeleyev's concerns about major environmental problem of the XXth century city - horse poo. Megatons of horse poo. How could possibly we handle that? History proved that technology can save us from predicted environmental impact of horses made by one of the brightest minds of its time. Same thing with uranium depletion problem. In 100 years we probably shall have effective thorium reactors, thanks to Norway and China, solar power stations on the Moon and who knows what else. Just lets don't stop thinking and tinkering.
• pjc50 11y ago
  Nuclear generates a lot of controversy. On paper it looks great; in practice there it turns out to be very expensive or have nasty problems buried in the details. For example, molten salt reactors have corrosion and reprocessing problems. I don't blame the author for refusing to take a position on nuclear.
  • DennisP 11y ago
    The Oak Ridge molten salt reactor lasted four years without serious corrosion. Terrestrial Energy and Thorcon are working on systems with sealed reactor cans that get replaced in similar timeframes. Reprocessing isn't a necessity; it extends fuel supplies but even Terrestrial Energy's simple burner design without reprocessing is six times as fuel-efficient as conventional reactors. Running on thorium is more complicated, but all the molten salt companies other than Flibe are starting with uranium.
    • pjc50 11y ago
      Reprocessing isn't a necessity What do you do with the spent fuel salt mix then?
      • DennisP 11y ago
        I'm not sure whether the "no reprocessing" plan would leave the fluorides and whatnot in the waste. It seems like it'd be relatively simple to separate that just to reduce the waste volume, after letting it cool for several years. I was referring to recycling the spent fuel into the reactor. From Terrestrial Energy's page on waste: - The IMSR burns its fuel far more efficiently than conventional reactors and leaves only one-sixth of the plutonium waste per unit of energy - The IMSR creates power far more efficiently than conventional reactors and leaves one-third less fission product waste per kWh of electricity - With the addition of IMSR waste fuel recycling, the IMSR can consume all its fuel and leave no plutonium waste - Recycling liquid fuel waste is technically and economically far more viable than recycling of the solid fuel waste of conventional reactors. http://terrestrialenergy.com/waste/ http://terrestrialenergy.com/waste/
  • 11y ago