59 pointsby vrganj7 hours ago9 comments
  • comrade12346 hours ago
    Here in Switzerland during some heatwaves they have to shut down nuclear plants too because the river water is too warm and adding warm water to it would kill the fish.
    • petre4 hours ago
      Would a cooling pond with controlled discharge into the river maybe mitigate this problem? One could also cycle the water from the cooling pond through the plant's cooling loop. The worse that could happen is evaporate the water from the cooling pond which is gets replaced with new water (sans fish) from the river.
    • number65 hours ago
      And it's not cold enough to cool the reactor
      • masklinn5 hours ago
        The reactor absolutely is not going to care, it’s the tertiary cooling circuit cooling for the steam turbines, it will have cooked off everything downstream long before it’s an issue.

        This is entirely an ecological and safety concern.

      • seszett5 hours ago
        No that's never the problem, even 40°C intake is cool enough to cool a reactor, it's all just a question of returned water temperature that can be harmful to a river if too high (generally the limit in Europe is set to 30°C).
        • masklinn2 hours ago
          It can vary by the river too (e.g. I remember Switzerland pulling back a reactor around 25 intake), and iirc there’s an absolute limit on the outflow (you don’t want to boil alive the stuff just off of the plant) and a relative one a bit downstream (you can’t heat the river to 20 when it’s freezing).

          These heatwaves reduce the margin from both directions, a hotter intake means you have less margin on the outflow, and the lower flow rate means there’s less water to dilute that outflow. And apparently for that specific plant there’s also the water level not even reaching the intake.

      • shakow4 hours ago
        Absolutely wrong. A difference of a couple degrees is not going to hamper cooling a reactor that is running at many hundred degrees.

        Just imagine what it would spell for your car otherwise.

        • ZeroGravitas3 hours ago
          I think both nuclear steam and car engines are affected by high ambient temp, gas and coal engines too.

          That is after all why they bring in water or air to car radiators, to cool them.

          Probably only a single percent or so for a few degrees change though.

          • voakbasda37 minutes ago
            Begs the question: coul reactors use radiative air cooling? Channel the water through a huge radiator and transfer the heat to the air
            • masklinn3 minutes ago
              No, a large reactor is way too power dense. An EPR reactor has a thermal output of 4.6GW.
  • pepperoni_pizza6 hours ago
    You can totally retrofit existing nuclear power plants for closed loop cooling. I'm not sure what the cost would be, though, but it might be worth doing.
    • Elfener5 hours ago
      I've read that in the case of Paks a retrofit doesn't make sense because the entire thing is so old and needs to be rebuilt anyway.

      However, hopefully, they change the plans for (stalled project) Paks 2, because that would've used the same cooling system as the first one.

      • 4 hours ago
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    • moffkalast5 hours ago
      Is it economically viable to run though? Natural draft towers or direct body of water cooling is used almost universally since it doesn't take any extra power. A large chunk of the powerplant's output would be running heat pump compressors to stop itself from exploding.
      • wongarsu5 hours ago
        Fully closed loop is probably not viable. But I suspect that's not the extreme GP might have meant.

        If for the sake or discussion we simplify cooling to four options:

        1: just passing river water through a heat exchanger for cooling

        2: ingesting river water, using it for cooling, then passing it through a cooling tower before returning it to the river

        3: pass the water output from the cooling tower directly back in the cooling loop, only ingest enough water to replace evaporation

        4: fully closed loop via direct heat exchange with air

        Then 4 is not very viable. But a lot of nuclear plants are stuck at 1 or 2, and each step up the ladder would allow them to operate in worse conditions. This one seems to be at version one

        • noduerme5 hours ago
          How do these things, whose sole purpose is to turn heat into electricity, end up with so much extra heat that it takes more energy than they produce to disperse it? Can't the excess heat in a closed loop system be captured and used to power the cooling? Sorry, maybe this is a stupid question.
          • Tade05 hours ago
            The heat is spread out to a much larger volume.

            Heat engines are most efficient when the temperature difference between the hot and cold side is high, so you need to keep it that way to extract energy.

            A nuclear power plant achieves this by converting extreme heat from a small, but very angry rock to a huge lake of slightly warmer water.

            There exist reactor designs which operate at higher temperatures, thus increasing efficiency, but they're complicated as everything needs to be more heat-resistant.

        • petre4 hours ago
          5. scrap 1..4 and build a gas cooled reactor instead.

          https://en.wikipedia.org/wiki/HTR-PM

      • emsign5 hours ago
        First of all you can't retrofit every npp with that, it's a lie. And eve; if you could, you are correct, it's financially not viable. Renewable energy is always the cheaper option by far.
  • Luc5 hours ago
    Of course a 1960's design isn't adapted to current weather conditions. That doesn't mean the whole technology is useless, like so many commenters imply.

    Any new build can and will include cooling adapted to hotter conditions.

    • one33seven2 hours ago
      There's a nuclear reaction in the sky beaming free energy to us, let's just use that
    • exploderate4 hours ago
      It's not matter of "can", it's a matter of "how much does it cost?" and "who pays for that?".
      • expedition324 hours ago
        Precisely why the Netherlands does not have nuclear power plants. Cheap coal. Cheap oil. Cheap gas. And now cheap wind and solar.

        They just absolutely cannot math the math which leaves ideology and this ain't France.

    • cucumber37328425 hours ago
      [flagged]
      • roenxi4 hours ago
        You're probably going to struggle to come up with a motive for that behaviour. It is much more likely that they simply aren't very thoughtful. Complex webs of deception in a public argument are certainly possible, but it generally relies on some group having a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
        • one33seven2 hours ago
          > a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.

          It's very obviously not in the interests of "big fossile" to go either solar or nuclear.

        • cucumber37328422 hours ago
          >You're probably going to struggle to come up with a motive for that behaviour.

          No, I'm not. Not in the slightest.

          Number in top right go up. Monkey brain feel goooooood when that happen. Monkey brain keep doing behavior that make that happen.

          > It is much more likely that they simply aren't very thoughtful.

          They're plenty thoughtful. They'll contrive all sorts of arcane logic, plausibly deniable lies and witty turns of phrase (some of which are quite impressive).

          What they're not is self aware (the dishonesty is a byproduct of that).

          > Complex webs of deception

          Those are possible but I don't think that's what's happening here.

          > but it generally relies on some group having a clear financial incentive to misdirect.

          Internet fanboys work for free. They have no financial incentive. Therefore we fall back to the monkey brain incentive.

  • josefritzisherean hour ago
    Desertification is next.
  • vrganj7 hours ago
    This is happening all across Europe right now - Romania, France too.

    https://www.euronews.com/business/2026/07/13/france-shuts-do...

    https://www.reuters.com/business/energy/hungarys-paks-nuclea...

    We keep having folks here argue that nuclear, not renewables are the path to take to get rid of fossil fuels. I have strong doubts - it feels like that doesn't account for the sad realities of climate change.

    • cinntaile7 hours ago
      People arguing for one alternative over the other are usually politically motivated. I feel like you are doing the same. Sometimes nuclear is a good fit, sometimes renewables is a good fit, sometimes fossil fuels are a good fit. Most of the time a mix is the best fit. It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible. All these systems are then built using assumptions, sometimes those assumptions no longer make sense after a certain period of time and sometimes you just temporarily or permanently have to adapt to the changes in the environment. This is an unusual but expected scenario for the nuclear plants along the Danube.
      • seszett5 hours ago
        > sometimes fossil fuels are a good fit

        There is simply NO safe level of fossil fuel use.

        • danw19794 hours ago
          There’s applications that we still have no alternative for though - e.g. aviation - so we’ll have to accept the burning of hydrocarbons there.

          Not fossil hydrocarbons forever, of course, but synthetic kerosene might be a thing soon enough.

        • ben_w5 hours ago
          Disagree, it's just that the safe level is around 0.1% of current use (though I don't just mean use of fossil fuels for electricity, I mean *everything*).
        • cinntaile4 hours ago
          I don't know what you mean with "no safe level of fossil fuel use". It doesn't mean anything without contextualizing that statement.
      • dudefeliciano5 hours ago
        The point they are making is that climate change will further push these conditions, so are we willing to build more nuclear power plants, knowing that by the time they are ready to go online this problem will be worse? Or better to invest in renewables which can be implemented today and will alleviate this problem? A mix of both with heavy majority of renewables and nuclear/fossil only to guarantee baseloads seems like the best idea to me.
      • stavros6 hours ago
        Agreed, whenever I hear someone say "we need more/less nuclear and less/more solar/wind", I hear "let's burn more fossil fuels while we uselessly split hairs".
      • Krasnol3 hours ago
        > People arguing for one alternative over the other are usually politically motivated.

        If you can spend a Dollar only once, you might end up with renewables. People can be economically motivated too. No reason to draw politics in an already heated discussion.

        • cinntaile3 hours ago
          > It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible.

          I mentioned all of this in my message. What was unclear about it or did you perhaps not read past the first sentence?

      • vrganj6 hours ago
        I'm not really opposed to nuclear power politically. I just think it's a non-starter given the much higher cost, complexity of buildout and lack of reliability.
        • deepsummer5 hours ago
          In countries with dark winters and without enough hydro power, the only reliable alternative are fossil fuels...
          • comrade12345 hours ago
            Iceland has no nuclear power plants.
            • defrost5 hours ago
              Iceland is a small area, small population outlier literally sitting on two plates rubbing up against each other and a relative excess of active volcanism and large lava fields.

                About 85 percent of the total primary energy supply in Iceland is derived from domestically produced renewable energy sources. Use of abundant hydroelectric and geothermal power has made Iceland the world's largest electricity producer per capita.
              
              ~ https://en.wikipedia.org/wiki/Iceland

              What works for Iceland works in few other places to the same degree (New Zealand, Yellowstone, places with thin crust and feisty caldera's).

              • number65 hours ago
                Germany also has potential for 85% geothermal energy.

                There are some interesting spots here but it's generally enough through the country to do it everywhere.

                Munich gets quite a lot of it's energy from geothermal sources

            • deepsummer5 hours ago
              Countries like UK, Ireland, Germany, Danmark, Netherland, Poland also have dark winters. Solar in winter is only about a fifth of production in summer months.

              Iceland has geothermal, which is amazing, but won't help central Europe.

              • ben_w5 hours ago
                Those places also have a huge wind resource in the form of the North Sea, for Ireland whatever the other bits of that submerged continental shelf are called, and for Poland the Baltic: https://globalwindatlas.info/en/

                This is important because wind season anti-correlates with PV season.

                Plus, it's not like north-south power lines are beyond the wit of mankind. The US western interconnection includes both Canada and Mexico: https://en.wikipedia.org/wiki/File:NERC-map-en.svg

                • deepsummer4 hours ago
                  Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further. Storage in the required dimensions is an unsolved problem.
                  • ben_w3 hours ago
                    > Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further.

                    Not for the combination of [continent-wide, offshore, the Atlantic coast].

                    The Atlantic continental shelf isn't correlated with the Baltic.

                    Offshore Dunkelflaute is much shorter than on-shore.

                    > Storage in the required dimensions is an unsolved problem.

                    Also false. The required quantities even of batteries is comparable to electrification of road transport.

                    Also, independently of batteries, hydro plants come in two flavours that people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty, and just the currently and soon-to-be closed coal mines in the EU can be converted to around 13 TWh of pumped storage: https://gfzpublic.gfz.de/rest/items/item_5038282_1/component...

                    And it's not like we can't dig more holes if we wanted to, we dig holes to get out rocks even though rocks are one of the cheapest things you can buy.

                    • deepsummer2 hours ago
                      > The Atlantic continental shelf isn't correlated with the Baltic.

                      How do you transmit the power? Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?

                      > Offshore Dunkelflaute is much shorter than on-shore.

                      That reduces the storage requirements a bit, but there is not nearly enough offshore. And offshore is expensive. That's why it's getting harder to find investors.

                      > The required quantities even of batteries is comparable to electrification of road transport.

                      That doesn't prove it's possible, but makes it even harder to get the required quantities.

                      > hydro plants come in two flavours that people often mix up: generation, and storage

                      Hydro requires the right geography. Is there any potential for hydro left in central Europe?

                      > EU can be converted to around 13 TWh of pumped storage

                      That would be a good amount of storage. But has this ever been tried? I would guess that's quite dangerous: https://www.youtube.com/watch?v=LseK5gp66u8

                      • deepsummeran hour ago
                        Max comment nesting reached. Instead of going through your response one by one, let me just say one thing: the premise and promise of the whole energy transition are based on studies that completely underestimated the physical and engineering challenges in practice. That's why we are where we are. Energy costs have gone up; CO2 emissions have not. I wouldn't believe any study before it has been implemented at scale, at least in a region or small country.
                      • ben_w2 hours ago
                        > How do you transmit the power?

                        The usual way.

                        > Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?

                        They can sell the power, you know. This already happens.

                        > That reduces the storage requirements a bit, but there is not nearly enough offshore.

                        It more than covers it.

                        Even a Dunkelflaute period is reduced, not zero, output. Those seas are huge, and the normal wind there is fast; even on a continental-shelf-spanning Dunkelflaute (much rarer than "just Germany and Poland"), the capacity in those waters *even with that reduction* is more than EU demand just by itself, which in practice means "not building as much as possible".

                        > And offshore is expensive. That's why it's getting harder to find investors.

                        Compared to onshore wind. But even offshore wind is cheaper than new-build nuclear, coal, and has strong overlap with new CCGT.

                        Even then, it's not hard to find investors: the US went as far as banning it because the investors were actually happy to invest.

                        The limitation on investors right now is that we're transitioning faster than any previous energy transition before, while also having other things to also invest in. It's like how big tech in the US is running out of people to get money from to spend on data centres, the limit isn't actually building them, it's how fast they're getting built when your answer to "how many would you like to order?" is "yes".

                        > That doesn't prove it's possible, but makes it even harder to get the required quantities.

                        The fact that EVs are for sale, however, does.

                        > Hydro requires the right geography. Is there any potential for hydro left in central Europe?

                        I thought you might say something like that, *which is why I literally wrote what I wrote*:

                          people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty
                        
                        And then linked you to a document, with a quote from that document, about using coal mines. The document you replied to with doubts, supports the conclusion you've just denied.

                        Also, I already saw all of Tom Scott's videos when they were new. As per the document:

                           Finally, the realisable potential includes projects that are not only technically and economically feasible but also aligned with regulatory, environmental, social and implementation timelines, facilitating their implementation within short to medium time frame.
                  • frm883 hours ago
                    Storage in the required dimensions is an unsolved problem.

                    No, it's not. Decommissioned nuclear plant infrastructure used as massive battery storage.

                    https://gesi-deutschland.de/en/gesi-project-presented-in-gro...

                    • deepsummer3 hours ago
                      870 MWh? It would take about 500 of them to make it through a 1-2 week dunkelflaute.
                      • ben_w2 hours ago
                        Why do you think that's a criticism?

                          The following table shows that in total 2264 installations have been identified in the EU ETS to be power plants, which have reported emissions in at least one year since 2005. The fuel of 1440 power plants have been identified. Of this there are 124 lignite power plants, 284 hard coal power plants and 2  power plants using blast furnace gas. There are 57 power plants using oil products. The majority of the plants uses natural gas (858 plants). About 824 plants have not been matched to a fuel yet.
                        
                        - page 8, https://www.eionet.europa.eu/etcs/etc-cme/products/etc-cme-r...
          • oblio5 hours ago
            Wind + storage, geothermal.
            • deepsummer5 hours ago
              Storage of energy in the dimensions required for weeks with almost no wind is an unsolved problem. Right now, we can't store enough to make it through a single night without using fossil fuels. Most countries don't even have the capacity to store the energy for a single hour.
              • RandomLensman5 hours ago
                As we can store fossil fuels for weeks of demand, we can store the required energy in chemical form, no? Germany has huge natural gas storage, for ezample.
              • emsign5 hours ago
                Geothermal and storage is worth investing in, investing in nuclear is not. NPPs are simply too expensive and you won't find investors unless you heavily subsidize it with tax money. Only compnies willing to invest in NPPs are those with virtually free money: the handful of AI big tech giants.
                • deepsummer4 hours ago
                  How can you be sure of that before even having a practical and proven solution for the required scale of storage?
                  • ben_w2 hours ago
                    We have proven solutions.

                    We're building the factories to make them as fast as we can find investors with money to spend on them, because they're already cheaper than fossil fuels which are themselves cheaper than nuclear.

      • paganel5 hours ago
        Everyone is politically motivated on this subject, and that's a good thing, because this is a political decision by default, where the "political" is comprised of is, the voting citizens. We can't let decisions like these be taken by unelected technocrats alone.
        • gib4445 hours ago
          I'm not filled with joy about my chav ("redneck") neighbours weighing in on nuclear vs solar and climate change and national and international energy markets and power distribution...

          I don't have a clue either. Don't ask for my vote on how to power a country. Take my taxes and use them to listen to experts

          • dudefeliciano4 hours ago
            Plot twist, the experts are lobbyists and they convince our politicians to start fracking and massively increase the use of "clean coal"
        • cucumber37328425 hours ago
          >and that's a good thing, because this is a political decision by default,

          Why is it a good thing that everyone and their brother seeks to apply state violence to micromanage what should be a fairly arcane technical issue?

          >We can't let decisions like these be taken by unelected technocrats alone.

          Do you feel the same way about topics where your opinion differs substantially from the local majority?

          • andor4 hours ago
            Very few things are purely technical decisions. In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way). One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

            Edit: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals, from your dinner table and your company Slack to democratic institutions.

            • roenxi4 hours ago
              > One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

              I almost hesitate to ask, do you think that is the centralised or decentralised option?

              And, more directly, that is a bad theory. The billionaires will make money either way. It doesn't make a lot of difference to them as a class. They'll have an inclination to the cheaper form of energy because more energy -> more economy -> more money for them.

            • cucumber37328422 hours ago
              >In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way).

              The venn diagram between people who act like renewables are "freeing" (which make no mistake, they absolutely could be) and the people who advocate nonstop for government management of how they are deployed is too close to a circle for me to take such commentary seriously.

              >One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

              Ah, yes, billionares. Famous for not getting a cut when I buy a plug in solar panel from my preferred e-commerce site or big box store. /s

              The billionares have their money in everything. They get a cut of everything. You're just changing who gets the cut. And even if no billionaire is getting a cut, a publicly traded/owned investment bank or other corporate interest that would replace them is not really any less evil.

              >: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals,

              By not gaslighting myself into thinking politics is anything other than the process of deciding where, when and how state violence is applied.

              What backs up all those decisions other than credible threat of violence?

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      • ThePowerOfFuet5 hours ago
        >sometimes fossil fuels are a good fit.

        Oh come on.

    • eecc5 hours ago
      It’s the second of third year in a row that this happens.

      At some point it will be the new normal.

    • Cthulhu_5 hours ago
      It can be, but you need water, just like for solar you need sunlight and storage and for wind power you need, well, wind. Coal and gas rely on natural resources, which can be disrupted through geopolitical tension, like Russia's gas supplies into Europe getting cut off / sanctioned.

      Every power source has their tradeoffs, and I don't think anyone is denying that.

      What I do think is that people are making up arguments or statements that Other People have and call them out on it.

    • xinayder3 hours ago
      High temperatures also severely affect solar panel efficiency.
    • stefan_5 hours ago
      This is a technical problem with technical solutions. You can just fix things, you don't need to throw out 30% of your power generation to pay billions for climate change vagueposting.
      • Cthulhu_5 hours ago
        Kind of? I'm sure you can change a nuclear power plant so it doesn't rely on river or sea water but that's not something that can be done overnight.

        Restoring river water levels can't be done through technical solutions though, they rely on the weather and we can't control that. The European river levels are largely influenced by inland rain, snowfall, and glacier forming/melting; snowfall and rain has been meagre this year, glaciers have been melting and receding for decades now.

      • emsign5 hours ago
        Electricity costs by nuclear power is heavily subsidized by tax money in France, so the French are paying the higher costs anyway. Just saying. Maybe there's a technical solution involving nuclear but it's really expensive compared to the much cheaper technical solution: renewable energy.
    • flr035 hours ago
      Different reasons though, France has nothing to do with water level or availability. It's for environment protection.
      • emsign5 hours ago
        Not true at all. It's both in France and increasingly because the rivers run dry in the summer. Besides killing rivers for electricity and for "saving CO2" is as stupid as burning coal to keep HVACs running becauae the summers are getting hotter and hotter each year.
  • Ethan3127 hours ago
    A nuclear plant being forced offline by low river levels is a striking reminder that even low-carbon energy depends on climate-resilient infrastructure. How many plants across Europe face the same cooling-water risk?
  • raverbashing5 hours ago
    If only there was a power source that would excel during sunny and warm days, huh

    Then we could stop the nuclear plants when needed for cooling and maintenance

    • seszett5 hours ago
      > we could stop the nuclear plants when needed for cooling

      Well that's exactly what they did thanks to solar power provided by the rest of the grid, so your snark seems rather unwarranted.

  • emsign5 hours ago
    This is what nuclear power enthusists like to ignore when they talk about nuclear power being a solution to energy and climate change.
    • bsza5 hours ago
      Worth mentioning we also had to shut down the largest block in our largest gas power plant on the exact same day due to an unrelated error.

      https://www.dert.hu/hu/sajtoszoba/0/141 (in Hungarian, couldn't find an English source)

    • mertbio5 hours ago
      They also constantly criticise Germany and its nuclear power plant closures, linking almost every negative news story about the country to this issue. It seems they’re completely unaware of the potential consequences of operating a nuclear power plant.
    • fylo5 hours ago
      Every power source has trade offs, bud. They call solar renewable, but in fact panels have a shelf life, and take valuable finite resources and energy to manufacture. This is what climate change activists like to ignore /s
    • Cthulhu_5 hours ago
      Is that a fact or are you just trying to spark a debate?
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