Climate, the science, politics, economics and anything else


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  • This topic has 417 replies, 1 voice, and was last updated 6 months ago by Clark.
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  • #76084 Reply
    Clark

      Three meltdowns at the Fukushima Daiichi disaster, and two hydrogen explosions. Proper end-of-the-world TV; watch two nuclear power stations blow up. One of the explosions blew tonnes of spent fuel about a mile in the air; the design was that the pool for cooling fresh spent fuel was in the space above the reactor.

      I don’t think it killed that many people though. The tsunami was far worse, and washed a load of other toxic industries into the ocean too. Nuclear is just part and parcel of everything else we’re doing, more and faster all the time.

      Nuclear power could be done far better than it is.

      #76086 Reply
      ET

        I believe that the Fukushima reactors themselves were intact and resiliant to the tsunami but the cooling infrastructure was debilitated enough for the reactors to overheat. There are a number of other reactors nearby which had no incident. You can read all about it here though I guess they have a bias.

        Like a lot of things we need context. Nuclear accidents are somewhat like aircraft accidents, spectacular, sensationalised but infrequent and statistically still the safest way to travel. How may people die or are injured in the oil industry or mining industry that we never hear about?

        I’ve posted this YT vdeo before from David MacKay who has since sadly passed away from cancer. It’s approx 20 mins and in it he summarises the limitations of current renewables.

        “Nuclear power could be done far better than it is.”

        Yeah, I see China is bringing online a small test molten salt reactor this month for operation in September. The USA looked into thorium molten salt reactors back in the 50’s but abandoned it. Perhaps materials science has caught up enough to allow them?

        #76124 Reply
        Clark

          “I believe that the Fukushima reactors themselves were intact and resiliant to the tsunami but the cooling infrastructure was debilitated enough for the reactors to overheat.”

          Yes. An inevitable design problem with pressurised water reactors; cooling must continue no matter what caused reactor shutdown or heat from the fission products will melt the core causing complete loss of control of the reactor.

          I have read, but not confirmed, that the height of the land was actually lowered when the Fukushima site was built, so that less powerful seawater cooling pumps could be used. Had the original height been retained the diesel generators would not have been swamped and the reactors would have shut down in good order.

          “The USA looked into thorium molten salt reactors back in the 50’s but abandoned it. Perhaps materials science has caught up enough to allow them?”

          They had already solved the materials science problem, as demonstrated by the Molten Salt Reactor Experiment MSRE at Oak Ridge, 1964 – 1970:

          https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment

          Nixon had it shut down – (1) to save money, (2) because it wasn’t intended to produce plutonium for weapons and (3) it wasn’t in his home state. Weinberg was sacked for promoting it rather than Pressurised Water Reactors, another of his own inventions, which he described as “not safe enough for civilian use”.

          MSRE never actually ran on thorium because thorium, like U238, is not quite a nuclear fuel; it is just short of being able to sustain a chain reaction. Thorium and U238 are ‘fertile’ not ‘fissile’; they become fissile when irradiated in a reactor – thorium becomes U233 which is fissile, and U238 becomes plutonium, which is fissile. This is how ‘breeder’ reactors can “make more fuel than they consume”; by nudging a fertile material just across the line into becoming fissile.

          MSRE was the most versatile power-production reactor ever built. Without requiring redesign or major reconfiguration, they ran it on U233, U235 and, to an extent, plutonium. It could be possible to develop the design to “cook down” spent fuel; if so, there are a couple of centuries of free electricity as a by-product of disposing of existing “nuclear waste”.

          #76129 Reply
          michael norton

            I had thought, that it was now generally accepted that there had been a MELTTHROUGH at Fukushima.

            #76131 Reply
            michael norton

              Meaning the RPV is breached and hot nuclear material escapes.

              #76133 Reply
              Clark

                Michael, I haven’t looked into the situation at Fukushima for some years; there’s only so much bad news I can take, you know? There were four power stations at Fukushima; one was already shut down for maintenance when the tsunami occurred. When I last looked, it was generally accepted that all three running reactors had melted down. Investigations were proceeding trying to locate the melted core masses, but the radiation kept frying the camera robots they were sending in. It was widely assumed that the melted cores had melted their way out of the reactor vessels and into the ground beneath, but confirmation had been impossible to obtain.

                Yes, that could be called a “meltthrough”, or three meltthroughs, though the term hadn’t been coined at the time.

                As Pigeon English stated (August 20, 21:56 above), there are over 400 power reactors worldwide, most of which are on the coast and near sea level, to use seawater for cooling. But sea level is rising and weather events are becoming more extreme. Additionally, due to lunar orbit cycles, we have a decade of extreme coastal flooding approaching:

                https://www.nasa.gov/feature/jpl/study-projects-a-surge-in-coastal-flooding-starting-in-2030s

                I wonder how many of them should be de-fuelled? I think nuclear power may soon incur an enormous unforeseen cost.

                #76135 Reply
                michael norton

                  I believe the French, Framatone or whatever they are called today, part owned by Mitsubishi Heavy Industries, but essentially a creature of the French Regime had to “review” the specifications of their European Pressurised Reactor after the meltthroughs of Fukushima, Japan.

                  #76139 Reply
                  michael norton

                    Fukushima nuclear plant may have suffered “melt-through”, Japan admits
                    https://www.theguardian.com/world/2011/jun/08/fukushima-nuclear-plant-melt-through
                    Fuel rods have “probably” breached containment vessels – a more serious scenario than “core meltdown” – according to report.
                    The report, which is to be submitted to the International Atomic Energy Agency (IAEA), said fuel rods in reactors No 1, 2 and 3 had probably not only melted, but also breached their inner containment vessels and accumulated in the outer steel containment vessels.

                    Or in laymans terms they are fucked.

                    #76145 Reply
                    ET

                      I guess my point was that the Fukushima reactors themselves were not the primary point of failure, but the on-the-cheap cooling system was the primary point of failure, and that needn’t have happened if they had thought through their design. The end result is however the same.

                      That is the drive for molten salt reactors, they are inherently safer because runaway overheating can’t occur. If they do start to overheat the molten salt which contains the radioactive material will be forced out of the reactor carrying with it some of the radioactive material thus reducing the reaction and containing the runaway. However, I am not a nuclear physicist so I may not be aware of inherent dangers in these types of reactors that are not in the current ones.

                      My overall point is that if we are going to move away from burning fossil fuels to produce our energy we need a replacement. Our energy needs are not going to decrease. Right now, renewables simply are not enough.

                      #76151 Reply
                      Clark

                        Yes, breaching a containment layer is worse than meltdown, though it’s pretty much what would be expected after a full meltdown of a typical power reactor. I don’t know how bad a situation like Fukushima could get. Whether, for example, the core material could burn its way right out of all containment and start contaminating ground water or the ocean. Apparently that’s not happening and just capping them over will contain them, like Chernobyl. Officially, they were declared to be in “cold shutdown” in December 2011 – somewhat ironic as no one can get near enough to take a proper look. Here are some reports from 2017 onwards:

                        https://en.wikipedia.org/wiki/Timeline_of_the_Fukushima_Daiichi_nuclear_disaster#20_June

                        I don’t like water cooled reactors. Water is an unsuitable coolant because its boiling point is far too low; it explodes at nuclear reactor temperatures. It was a steam explosion that blew the 1000 tonne lid off the Chernobyl reactor.

                        But the Fukushima power stations were over forty years old, and they’d even been re-licensed beyond their design lifetimes. There are much safer reactor designs now. I’d like to see some molten salt and other designs prototyped, but for half a century power reactor development has stagnated, often due to public opposition.

                        These days, wind and solar electricity are cheaper. In particular, the growth rate of installed solar capacity is exceptionally high. But massive, international expansion of the grid is needed to take advantage of wind and solar. Nuclear power’s natural place is probably heavy industry’s centralised, continuous requirements – replacing coal for smelting steel, for instance.

                        #76164 Reply
                        michael norton

                          Part of the problems are mindset, advertising, over consumption, greed and built in Obsolescence/upgrading.
                          My car is 30 years old and has done 200,000 miles. I bought my washing machine about eight years ago, second hand. I just bought a new push bike, the other one I bought new 28 years ago. I did buy a new T.V. and satbox as I could barely ever watch T.V. as the signal was so weak. I almost never throw clothes away, I do get through a pair of walking boots about every two years as I am always out walking. My couch cost nothing, a neighbour gave it to me. Almost everything I have is rubbish but so what, status is meaningless. You should not need or desire more stuff.

                          If people could understand that ever more stuff is killing our World, could they be convinced to repair stuff, make stuff themselves. Convincing everybody in the World to buy a new $40,000 Tesla, will mean dumping hundreds of millions of I.C. cars, before they are worn out, more and more power stations will be needed to be constructed using concrete, to match the new need for electricity, concrete is bad for the atmosphere.
                          Where will this push to have new stuff lead?

                          #76173 Reply
                          michael norton

                            In the tense days ten years ago when smoke rose around the stricken Fukushima Daiichi power station as if from a battlefield, when hydrogen explosions tore the reactor buildings apart and workers fought for their lives and Japan’s future, it seemed as though we might be watching the death throes of the nuclear dream.
                            https://www.bbc.co.uk/news/science-environment-17287740

                            It was after this group of disasters that France decided to revise its plans for the European Pressurised Reactor, The French President Hollande & Ségolène Royal (the mother of his children) put in train, a promise to shutter old Nuclear plants in France and reduce the reliance on France of Nuclear Power, eventually down to 50% from about 70% – 80%. Fessenheim has now closed. Part of the plan was, when the EPR was opened in Flamanville, other, older Nuclear Reactors would be switched off. Flamanville, seems to have had endless problems, including poor welding.

                            Germany, Italy, Austria, Switzerland, all have decided they can no longer take the risk of Nuclear Power.

                            #76237 Reply
                            Clark

                              Michael, I very much agree with your August 23, 09:44 comment, about consumerism etc.

                              There are of course political issues deeply entwined with the points you mentioned, but right now I am far too miserable to write about them.

                              I agree that no more water-cooled power reactors should be built, especially near the rising oceans. If Weinberg had not been sacked, for political reasons, we would probably have clean, safe, inexpensive nuclear power by now. But please don’t get the dangers of nuclear power out of perspective. Mining kills many more people, and burning coal releases more radioactivity. Even hydroelectric has a higher death toll; look up some of the dam failure disasters.

                              #76239 Reply
                              ET

                                So, if we are to stop using fossil fuels what are we going to replace them with? That’s the fundamental problem. Whilst reducing wasted energy, reducing unnecessary goods and transport etc etc will help it won’t be enough on it’s own. If we stopped using fossil fuels tomorrow without replacements an order of magnitude more people will die than covid has caused, if we don’t and climate behaves as predicted the same thing happens.

                                #76245 Reply
                                michael norton

                                  I am not against Methane, even Scotland is constructing Methane powered ferries.
                                  I am not sure what the actual fuel is they use on the newer Royal Navy ships, “gas turbines”
                                  More and more boats are now using Methane.
                                  Germany is shuttering all of its Nuclear Plants and going for a mixture of Methane from Russia, Coal from Poland and renewables.

                                  #76247 Reply
                                  ET

                                    Methane is a far more potent greenhouse gas than CO2 and stays 20 years in the atmosphere. Extracting it from methane gas deposits results in 15% leakage to atmosphere. It’s also being used to produce “blue” hydrogen which may be actually worse than just burning coal.

                                    Chair of UK hydrogen body quits over support for fossil-fuel dependent ‘blue hydrogen’ championed by Tories.

                                    “Blue hydrogen is at best an expensive distraction, and at worst a lock-in for continued fossil fuel use,’ says Chris Jackson”

                                    The counter to that is that it would lead to a hydrogen infrastructure being acquired and blue hydrogen could then later be replaced by “green” hydrogen produced by hydrolysis from renewables at 40% efficiency (60% electric power driving the hydrolysis is wasted as heat) with power derived from an already at best 20% efficiency coverting solar to power when the sun shines.

                                    My feeling is that those who have paid for rights to natural gas reserves don’t want their investment tanking and their rights worthless. I can’t say I blame them trying but if the goal is reducing greenhouse gases drastically methane is not the answer unless they sort out the leakage problem which they will not.

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                                    #76261 Reply
                                    Clark

                                      Methane is CH4, ie. one atom of carbon bonded to four atoms of hydrogen, so if burned perfectly with oxygen you’d get one molecule of carbon dioxide and two molecules of water vapour:

                                      CH4 + 2O2 → CO2 + 2H2O

                                      So even without leakage, burning methane still produces carbon dioxide. Methane is the simplest of the hydrocarbons. It has the highest hydrogen-to-carbon ratio of any hydrocarbon, but it still has carbon.

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                                      #76277 Reply
                                      michael norton

                                        Carbon can’t be the devil, almost all life is carbon based.
                                        Why is Scotland constructing Methane burning ships? Sturgeon is as green as grass with her new green mates.
                                        If Germany is the great white hope of Europe, why are they making their base Methane?
                                        Methane is cleaner than clean compared to brown coal.
                                        All life can not stop because of covid.
                                        All life can not stop because some do not like carbon.

                                        #76308 Reply
                                        ET

                                          “Carbon can’t be the devil, almost all life is carbon based.”

                                          Who is stating it is? It isn’t about carbon per se, it’s about certain molecules acting as greenhouse gases some of which contain carbon some of which don’t.

                                          The sun heats the planet, the planet reflects some of that heat back to space cooling us. Greenhouse gases absorb some of that reflected heat and re-reflect it back to us, warming us more. The energy required to heat the atmosphere through 1 degree Celsius is equivalent to 144,000,000 Hiroshima bombs exploding simultaneously (see below). All that extra energy is in the system and climate events thus are more energetic (more rain, more snow, more heat, more whatever depending on the climate event). To heat the oceans through 1 degree Celsius requires 1000 fold more energy than atmosphere so even a small increase in ocean temperatures means a large amount of energy. Heat is energy ultimately (in the pure physics sense) and a warmer planet means more energy stored within its systems.

                                          “Why is Scotland constructing Methane burning ships? Sturgeon is as green as grass with her new green mates.
                                             If Germany is the great white hope of Europe, why are they making their base Methane?”

                                          Your argument is that if Scotland and Germany are saying methane is ok, then it must be ok? Really? Perhaps Scotland is invested in its natural gas reserves and Germany in NordStream 2?

                                          “Methane is cleaner than clean compared to brown coal”

                                          I overstated the leakage issue (bad memory) but did you read either of the links in my previous post and did they not give pause for thought?

                                          “All life can not stop because of covid.”

                                          It never did stop anywhere if by “life” you mean daily activities. For sure, some stuff was curtailed.

                                          “All life can not stop because some do not like carbon.”

                                          Who is advocating for that? I’ll repeat, it’s not carbon that is the issue it is greenhouse gases (and pollution). The amount of carbon on the planet will remain the same no matter what we do.

                                          I made back-of-envelope calculations using figures from here and here should you wish to check them out.

                                          #76332 Reply
                                          Pigeon English

                                            In 2016, Germany generated 545 terawatt-hours (TWh) of electricity at an average rate of approximately 560 grams of carbon dioxide emitted per kWh. By contrast, France generated 530 TWh of electricity at an average rate of approximately 58 grams of carbon dioxide emitted per kWh. In terms of carbon emissions from electricity, this means that Germany emitted almost exactly ten times as much as France — over 300 million metric tonnes.

                                            That is the difference between using and abandoning nuclear

                                            #76381 Reply
                                            michael norton

                                              Just listened to a BBC pod
                                              https://www.bbc.co.uk/programmes/w3ct1l42
                                              Grey, Blue and Green Hydrogen.
                                              At the moment we overwhelming have Grey Hydrogen. Methane extracted from under the Earth, Methane used to make electricity. Methane used as a feedstock to extract Hydrogen, releasing Carbon dioxide into the atmosphere.
                                              The question seemed to be, would boiling a kettle of water at home, by using Blue Hydrogen be any less detrimental to the atmosphere than just using Methane to boil the water.
                                              The answer was: It was less damaging to the atmosphere, to burn Methane at home to boil a kettle of water, than either using Methane to make electricity, then using electricity to boil water at home, or using Methane to produce Hydrogen, then burning Hydrogen at home to boil a kettle of water.
                                              The scientist claimed under all options it was better just to use Methane.

                                              Perhaps he will tell our government?

                                              #76630 Reply
                                              Clark

                                                ET, August 21, 15:09 – I too am intrigued by the molten salt nuclear reactor designs, but development was cancelled and now we don’t have time to catch up. We should probably try building some reactors based on the Integral Fast Reactor and similar designs, because various countries have had experience in building something like it, eg. the 1959 Dounreay Experimental Breeder Reactor. Hitachi have a design called PRISM which they claim to be commercial. These reactors can burn spent fuel.

                                                There are various other small, simplified reactor designs, several of them PWRs. These reactors create spent fuel.

                                                I expect PWRs are what will get built because, what with submarines and icebreakers etc., there’s far more experience with them than anything else. But I guess storing the waste until fast reactors are developed is a trivial problem compared with trying to get all that CO2 back out of the atmosphere.

                                                Greenhouse gases trap in more heat basically just because they are bigger molecules than nitrogen (N2) and oxygen (O2). Emitting greenhouse gases is like putting sugar in your tea – it’s a lot more difficult to take out again.

                                                #76633 Reply
                                                ET

                                                  The news that China was bringing online a test molten salt reactor I got from here and corroborated elsewhere. It remains to be seen if it will be successful. There is a promotional YT video (It’s in chinese with subtitles). That New Atlas article is somewhat skeptical of its likely success. Whilst they are not the last word in science it explains some of the inherent safety advantages.

                                                  Ireland, along with other nations, prides itself on its no nuclear stance. I ask the question what can we realistically replace fossil fuel energy with in a short timeframe? Realistically being the operative word. Renewables are not enough and have issues of their own. Hydrogen relies on renewables to be non greenhouse gas producing itself, and hydrolysis is highly inefficient. Hydrogen produced from fossil fuels is just as bad if not worse. What are we left with? It might be that we need to make the least bad decision.

                                                  “Greenhouse gases trap in more heat basically just because they are bigger molecules ………”

                                                  To be more precise a greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. Water vapour is the most abundant GHG. All substances absorb and emit electromagnetic radiation at some frequencies. It’s a spectroscopic phenomenon. Hence we got that nonsense about 5G because oxygen absorbs in the microwave region. It’s not about their size per se but the fact that they absorb wavelengths in the infrared region then re-emit in the same wavelength region thus trapping heat in the atmosphere. If we didn’t have GHG’s we’d all freeze to death.

                                                  #76638 Reply
                                                  michael norton

                                                    In the United Kingdom we now make about twenty five times the amount of electricity by solar as one Magnox Reactor.
                                                    Solar has come on quite a bit
                                                    and there is way more to come, stunningly cheap and getting cheaper, it will be the cheapest form of producing electricity in the World, very easy to dismantle, when its day comes, unlike Nuclear Nonsense, the most expensive way to make electricity.

                                                    #76640 Reply
                                                    michael norton

                                                      United Kingdom = 16.8% nuclear power and 26.5% from wind, solar and hydroelectricity, many reactors will be shut down over the next four years.
                                                      Renewable sources of electricity, certainly seem the way forward, getting cheaper and more efficient all the time. No doubt huge battery packs will be used, as in Australia.

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