• dan69@lemmy.world
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    13 小时前

    I’d like to thank some post on Mastadon, which really boiled down how and what a nuclear power plant works to provide power… the little things.

    • Captain Aggravated@sh.itjust.works
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      1 小时前

      You’ve probably heard of an internal combustion engine, like what power cars and airplanes. Well there’s such a thing as an external combustion engine - a steam engine. A steam engine just needs some source of high pressure steam, the source of heat you find to boil the necessary water is almost a separate problem. You could use a wood fire, a coal fire, an oil fire, a natural gas fire. I’ve seen a small steam engine that runs on a tea candle. Heat from a geothermal vent, concentrated sunlight, or nuclear power.

      How about a diesel engine? Large oceangoing vessels with 2-stroke diesel engines the size of a duplex put out a lot of waste heat, plenty enough to boil water and run a steam turbine engine. The diesel engine provides main propulsion, the steam engine powered by its exhaust provides electricity. Ships with such a system can shut down their aux engines while underway saving tons of fuel per voyage.

  • Tiempo@lemmy.dbzer0.com
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    1 天前

    What is worst is that if we look deeper, we find out that everything is just turning the mill

    The only advance would be solar that was capable of not using a mill that have to turn… Everything else? Just a fucking mill

  • 👍Maximum Derek👍@discuss.tchncs.de
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    1 天前

    Face it, all power is water, all stories are Hamlet, all food is grass, and all music is Pachelbel’s Canon. Reality’s budget is running out and it’s having to reuse assets.

    • fullsquare@awful.systems
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      1 天前

      there is a power generation scheme that uses high temperature fuel cells. optimally it could run on hydrogen only, but because it runs hot, it is able to take almost any flammable gas, along with some steam, and it forms hydrogen internally, then oxidizes it. this alone generates bulk of electricity, but offgas is hot, so it goes to heat exchanger which boils water, which then turns steam turbine

        • fullsquare@awful.systems
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          1 天前

          it replaces gas turbine with a fuel cell, which is a good couple % more efficient than CCGT. still under development. there is also another variant where hot offgas is generated under pressure and expanded directly. no steam, same effect

    • rumba@lemmy.zip
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      6 小时前

      Relatively, yes, and not to mean somewhat. For the amount of power generated, the spent fuel/water is really not that significant.

      Nothing is purely clean. Making solar panels and batteries isn’t clean; it’s just that coal and natural gas are extremely dirty on a mass scale, environmentally speaking.

      If we could get the ‘big scare’ concept of Nuclear under control, we could make some systems that are even cleaner. There’s no apetite for that though.

      • woelkchen@lemmy.world
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        5 小时前

        Relatively, yes, and not to mean somewhat. For the amount of power generated, the spent fuel/water is really not that significant.

        Absolutely speaking, controlling nuclear waste for hundreds of thousands of years is impossible and any rationalization when cheaper and regenerative options exist is idiotic.

        • rumba@lemmy.zip
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          5 小时前

          controlling nuclear waste for hundreds of thousands of years is impossible

          Purchase 10 sq miles iround a mine Fill below any water table, fill with concrete

          Deep drill past aquifers drop waste in hole.

          Not cheap, but you can really do that.

          any rationalization when cheaper and regenerative options exist is idiotic.

          Ignoring options with the benefits of 24x7 steady state generation is far more idiotic.

          • woelkchen@lemmy.world
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            5 小时前

            Purchase 10 sq miles iround a mine Fill below any water table, fill with concrete

            And that concrete is 100% carbon neutral and will never be affected by earthquakes.

            Deep drill

            When drilling is suddenly OK, then forego the nuclear reactor and go straight to geothermal.

            Ignoring options with the benefits of 24x7 steady state generation is far more idiotic.

            Tell that to your nuclear waste buddies who oppose geothermal.

            • rumba@lemmy.zip
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              5 小时前

              100% carbon neutral and will never be aff

              • edit: needed a space

              deep enough, below the water table. (if it even exists where you pick a location) no big deal. There’s worse things down there already than moderately low level radioactive metals. It’s not like we aren’t fracking underneath peoples homes now. releasing dangerous gasses, causing earthquakes, yada yada. That’s the other good part about the deep desert: it’s already inhospitable enough that people don’t gather there uniformly in great numbers. If you buy up some land and cordon it off, it’s not really screwing with people. What if you put it deep in the Sahara?

              When drilling is suddenly OK, then forego the nuclear reactor and go straight to geothermal.

              Geo is a great idea, sadly they have trouble getting it to scale, and locating hot enough pockets proves elusive. If you’re in volcanic areas, medium-sized geothermal is amazing. IIRC Iceland uses it to great effect but it doesn’t work just anywhere. We can’t drill so deep that it gets hot enough to make a difference; you need to find a spot where the crust is already thin.

              Now that’s not to be confused with geothermal at the house level for heatpumps, that is straight up awesome but works on a very different concept and can’t really scale at all… well it would be nice if all these fucking datacenters would use that instead of evaporative loops. but that’s a different story.

              • edit 2 looking at the carbon footprint of concrete, you’d spend more carbon drilling the hole and getting the waste to the hole than the plug you used to fill it. and you’d be able to store decades of terawatts of energy refuse in that hole
    • chaogomu@lemmy.world
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      1 天前

      Extremely.

      Even adding in construction and mining, it has the lowest carbon per KWh out of any option. Even Hydro comes out worse, due to the years of carbon and methane emissions from the decaying plant matter at the bottom of the newly formed lake.

      Wind and solar are down there, but the mining costs and the low output per unit tend to bump the numbers.

      Noted, that’s just the carbon released. There are other metrics, and nuclear tends to meet most all of them because it’s very heavily regulated.

      • Random Dent@lemmy.ml
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        8 小时前

        Humanity’s relationship with producing energy continually blows my mind, and it’s one of the main things that makes me think that maybe we do live in a simulation.

        We discovered fossil fuel energy, which was fine for a bit to kick off the industrial revolution, but obviously is super harmful in the long term. Then just as it was starting to become a problem, the universe went “okay, here’s this magic rock that just gives off energy, you can use that to generate massive amounts of power with no carbon.” And we just went “nah.”

        So then, the universe is like, “alright then, how about this: you can just get it from the sun, the air and water. Again no carbon and it’s infinite free energy forever, you’re welcome.” And again, we were like “no we want to just burn fossils.” Even now at the ecosystem is visibly collapsing around us we’re adopting it somewhat, but still dragging ass on it like crazy.

        It’s like whoever’s running the simulation keeps dropping the difficulty level to help us not die, and we just won’t accept it. I fully expect in the next century or so we’ll figure out cold fusion, build like two plants and humanity will just collectively go “BORING” and dig up more coal again.

        • Horse {they/them}@lemmygrad.ml
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          5 小时前

          It’s like whoever’s running the simulation keeps dropping the difficulty level to help us not die, and we just won’t accept it. I fully expect in the next century or so we’ll figure out cold fusion, build like two plants and humanity will just collectively go “BORING” and dig up more coal again.

          it isn’t “humanity” who stands in the way of moving on from fossil fuels, it’s a few hundred extremely wealthy assholes who own the fossil fuel industry


      • Rainbowblite@lemmy.ca
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        7 小时前

        The Nuclear industry actually makes an effort to clean up after itself. Coal wouldn’t be such a big deal if they captured the carbon before it hit the atmosphere.

      • fullsquare@awful.systems
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        15 小时前

        Coal ash (from some mines) contains so much uranium that if emissions like this were detected near NPP all hell would break loose, but nobody cares. Energy content of that uranium can be higher than what was released during coal combustion

        • woelkchen@lemmy.world
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          14 小时前

          “coal ash is worse” doesn’t make nuclear waste clean and non toxic. Both are dirty, just different kinds of dirt. Geothermal is an excellent “boil water” technology independent of weather and without toxic waste.

          • chaogomu@lemmy.world
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            9 小时前

            Coal ash is dumped into a retaining pond by the ton.

            Nuclear waster is highly controlled and produced by the pound and sealed into giant casks that can be struck by a full speed train without beaching.

            • woelkchen@lemmy.world
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              7 小时前

              Coal ash is dumped into a retaining pond by the ton.

              I’m not defending coal, so stop trying that whataboutism BS with me.

          • fullsquare@awful.systems
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            14 小时前

            there are still coal powerplants around and any replacement is better. geothermal doesn’t work everywhere

            • woelkchen@lemmy.world
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              7 小时前

              geothermal doesn’t work everywhere

              So what. That’s why power lines exist. Coal is BS, nuclear is BS. A healthy mix of renewables is possible right now.

      • Zagorath@quokk.au
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        18 小时前

        This page’s “Life cycle CO2 equivalent (including albedo effect)” page says Nuclear is just a hair worse than onshore wind in the median case, significantly worse than both on- and offshore wind in the worst case (worst for both types), and slightly better in the best case. In best case, hydro actually beats nuclear.

        Also, TIL tidal power isn’t commercially in use. I swear we were learning about it in school 20 years ago, and were not even told then that it wasn’t viable.

        Including the effects of albedo seems rather straightforward and worth doing. Of course it neglects some more complicated factors, like opportunity cost of staying on fossil fuels in the meantime for the 20+ years it takes to build nuclear. A convenient part of the reason that the biggest proponents of nuclear tend to be those politicians and special interests who also support fossil fuels.

        • chaogomu@lemmy.world
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          8 小时前

          You don’t need giant 20 year plants.

          Small Modular Reactors can be built and deployed much faster.

          You don’t need to power an entire state with a single plant. You can scale it down to powering a single town. That’s the current push, mass production of SMRs.

      • Richard@lemmy.world
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        14 小时前

        That’s one hell of a claim. In fact such an outrageously bold one that you shouldn’t be able to post a comment like that without citing a reputable source.

        • Holytimes@sh.itjust.works
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          12 小时前

          It’s not that bold or outrageous… It’s been common knowledge for over 40 years.

          Basically since the dawn of nuclear power plants we knew it was the cleanest form of energy generation. That was literally its selling point.

          The problem was the fear of radiation if shit went wrong.

          • oce 🐆@jlai.lu
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            10 小时前

            The consequence of this legitimate fear is crazy security and the cost of it. To the point where the cost of new nuclear now struggles to compete with renewables. The new generation plants EPR are catastrophic in terms of budget and schedule.

            • chaogomu@lemmy.world
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              9 小时前

              The thing is, it’s not a legitimate fear.

              Radiation needs respect, but it’s not the magic death sauce that Movies and the Oil industry claim it is.

              We swim in a sea if radiation every moment of every day.

              • oce 🐆@jlai.lu
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                8 小时前

                I studied physics at university, I also had the opportunity to visit Fukushima Daichi after the catastroph and one of the new EPR. Enrichied fuel used in nuclear power plants and the byproducts of the reactions are dangerous. The multiple security measures are not there for the pleasure of spending budget.

                • chaogomu@lemmy.world
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                  8 小时前

                  Dangerous, but slightly less so than you’d think.

                  Unless you already know that LNT is bullshit.

                  Also, the evacuation of Fukushima caused far more death than any radiation exposure.

        • cynar@lemmy.world
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          15 小时前

          Coal plants put out more radioactive material than even the bomb factories they call nuclear power plants. Newer plant designs are FAR more fail safe too, and some can actually ‘eat’ the waste from older plants.

          New nuclear is right up there with renewables, with the added bonus of being great for baseloads. The only problem is we needed to be building it 20 years ago, since it takes a long time to design, permit and build them properly. If we try to rely on them now, it will be too late.

          • 0x0@lemmy.zip
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            13 小时前

            since it takes a long time to design, permit and build them properly.

            That’s been rigged by design due to… interests… it doesn’t take that long to build one.

            • cynar@lemmy.world
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              13 小时前

              Fully agreed, though it’s also something you really don’t want done on too much of an accelerated timeline. Rushing the construction, when the fail-safes rely on it, and it will be an absolute bitch to fix later, is a poor plan.

              Unfortunately the red tape has become far too risk adverse. E.g. the reactors china is now building were designed in the UK. The UK government killed 5 attempts to get them built through red tape and time killing. Eventually a Chinese scientist found out about the plans. (With permission) he contacted the Chinese government. Sufficient to say, those plans formed the basis for the newer Chinese reactors they are building out now. They are also exporting the expertise, since most western countries have had their skilled engineers reach retirement, before passing on their skills and knowledge.

              In practice, you are looking at 5-10 years minimum, from site selection to power on.

              • 0x0@lemmy.zip
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                12 小时前

                True

                In practice, you are looking at 5-10 years minimum, from site selection to power on.

                Still beats 20.

                • cynar@lemmy.world
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                  11 小时前

                  Very true. It unfortunately doesn’t include the delays from bureaucracies throwing excessive red tape at the project, with the goal of, if not killing it, kicking the decision down the road till it’s someone else’s problem. The UK government has been problematic on that front.

                  I might be an optimistic pessimist.

            • cynar@lemmy.world
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              14 小时前

              It’s relative harm. New nuclear is far cleaner than coal, and can slot into it’s place in the grid. We should have done this decades ago, but the plans languished till china found out about them. (Much to the designers joy)

              It’s also not an either/or situation. As china is demonstrating, there is a limit to how quickly you can roll out renewables. Doing other, pollution reduction in parallel makes sense.

              Taking nuclear off the table was the biggest win the oil barrons pulled off.

              On a plus side, we will finally find out if fusion is viable in the next 5-10 years. The first over-unity test reactors, designed for sustained operation are being built.

              • woelkchen@lemmy.world
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                12 小时前

                Renewables are cheaper than building new reactors. Fusion is always viable in 10 years.

                • cynar@lemmy.world
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                  12 小时前

                  Fusion has been 10 years away, with proper funding. It never got that funding. It struggled to maintain the break even funding to keep skilled people employed, and the lights on.

                  The difference is that over unity has been achieved, in a normally sustainable manner. The funding is such that it’s 5-10 years at current funding. Most of that is building the actual test plants.

                  I fully agree that renewables are currently the best cost option. The catch is that they are not viable everywhere. They are also inherently low density, so can get expensive in certain areas.

                  Basically, we want a mix of options, to fit local requirements. Nuclear (and later fusion) should be part of the plan.

                  In practice, I’m of the take what we can get. We need to crash CO2 output, and we need to do it yesterday. Anything speeding that up is a win, as far as I’m concerned.