• smegforbrains@lemmy.ml
      ·
      edit-2
      9 months ago

      The positive void coefficient was directly responsible for the disaster: During low power operations the effect caused water vapour bubbles to be created in the reactor. Because of the lower density of the vapour the moderation of the reaction did no longer work and the reactor spiraled out of control. All the while there was no feedback to the control room about the increased reactivity, so the personal had no chance to assess the situation correctly. This lead to the uncontrolled chain reaction and the explosion of block 4.

      After a while Nikolai Steinberg conducted an experiment in the other blocks of Chernobyl which showed that the positive void coefficient was causing the reactor to spiral out of control in low energy production scenarios.

      Sources:

      https://www.oecd-nea.org/jcms/pl_28271/chernobyl-chapter-i-the-site-and-accident-sequence

      There's a really good documentary about that, but alas it's in German: https://www.zdf.de/dokumentation/zdfinfo-doku/tschernobyl-die-katastrophe-paradies-100.html

      Nikolai Steinberg also coauthored a book about the accident: https://www.perlego.com/book/3418623/chernobyl-past-present-and-future-pdf

      • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
        hexagon
        ·
        9 months ago

        To sum up, there was an experiment conducted that caused the disaster, as opposed to it being a result of normal operation of the reactor.

        • smegforbrains@lemmy.ml
          ·
          edit-2
          9 months ago

          That's not right. The experiment was conducted after the explosion in an effort to prove Nikolai Steinberg's suspicion that the positive void coefficient caused the disaster. The experiment was a success and Steinberg's suspicions have been verified.

          • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
            hexagon
            ·
            9 months ago

            This is what caused the disaster

            On 25 April, prior to a routine shutdown, the reactor crew at Chernobyl 4 began preparing for a test to determine how long turbines would spin and supply power to the main circulating pumps following a loss of main electrical power supply. This test had been carried out at Chernobyl the previous year, but the power from the turbine ran down too rapidly, so new voltage regulator designs were to be tested.

            https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

            • smegforbrains@lemmy.ml
              ·
              edit-2
              9 months ago

              Exactly and during that test the positive void coefficient caused the reactor to spiral out of control with no feedback to the control room, as detailed in the earlier post.

              Here's a paper about that: https://hal.science/hal-03117177/document

              Even the nuclear power lobby organisation World Nuclear Association acknowledges that this is a massive design flaw: https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-power-reactors/appendices/rbmk-reactors.aspx

                • smegforbrains@lemmy.ml
                  ·
                  9 months ago

                  Tests will always have to be conducted to ensure normal operation. That's nothing out of the ordinary.

                  • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                    hexagon
                    ·
                    9 months ago

                    The question is how you conduct the tests, and of course we have learned a lot since that time. Modern reactors incorporate these lessons making them much safer.

                    • smegforbrains@lemmy.ml
                      ·
                      9 months ago

                      I agree that newer reactors are more safe than old reactors but there's still a significant risk involved. See Fukushima.

                      • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                        hexagon
                        ·
                        9 months ago

                        Fukushima is a reactor design from the 70s, and the risk with that design were identified at the time. Dale G. Bridenbaugh and two of his colleagues at General Electric resigned from their jobs after becoming increasingly convinced that the nuclear reactor design they were reviewing -- the Mark 1 -- was so flawed it could lead to a devastating accident. The problem with Fukushima was caused by capitalism.

                        https://abcnews.go.com/Blotter/fukushima-mark-nuclear-reactor-design-caused-ge-scientist/story?id=13141287

                          • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                            hexagon
                            ·
                            9 months ago

                            And by extension I'm saying that it has no relevance when discussing modern reactors which do not have the problems Fukushima reactor had. Meaning that you're trying to use a disingenuous argument to make your point.

                            • smegforbrains@lemmy.ml
                              ·
                              9 months ago

                              I don't agree. I think these accidents should make us aware of the dangers of nuclear power production and that there will always be a risk attached to it. There have been more than 30 nuclear power plant accidents with damage to the environment and the biosphere: https://en.m.wikipedia.org/wiki/Lists_of_nuclear_disasters_and_radioactive_incidents

                              • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                hexagon
                                ·
                                9 months ago

                                I know you don't agree. I've repeatedly stated that this discussion is pointless because we're not changing each other's minds here. It seems like you just want to keep restating what you believe over and over. I don't know to what end however. As the link I provided in the other reply shows, biosphere is doing just fine after nuclear incidents. If anything, it's actually doing better in Chernobyl than it did before the accident because humans are now gone from there.

                                • smegforbrains@lemmy.ml
                                  ·
                                  9 months ago

                                  You do know that the tens of thousands of people who developed cancer in the aftermath of the Chernobyl disaster are part of the biosphere? https://blog.ucsusa.org/lisbeth-gronlund/how-many-cancers-did-chernobyl-really-cause-updated/

                                  • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                    hexagon
                                    ·
                                    9 months ago

                                    Do you know that people develop cancer as a result of pollution from fossil fuels? https://www.targetedonc.com/view/fossil-fuels-present-considerable-cancer-risks

                                    • smegforbrains@lemmy.ml
                                      ·
                                      9 months ago

                                      Yes and again: Being against nuclear power production does not mean I'm a fossil fuel proponent. I think we have to get rid of both and achieve 100% renewables which is entirely feasible according to recent studies. Source: https://en.m.wikipedia.org/wiki/100%25_renewable_energy

                                      • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                        hexagon
                                        ·
                                        9 months ago

                                        Not a realistic option, especially if you want to have industry. I suppose Germany may just be advocating for NIMBY strategy here though. Perhaps you plan to just deinudstrialize and outsource manufacturing to countries like China so that your energy needs go down enough to make all renewables viable.

                                          • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                            hexagon
                                            ·
                                            edit-2
                                            9 months ago

                                            I mean we can just look at Germany and how things are going with the transition right now https://thehill.com/blogs/pundits-blog/energy-environment/291963-why-renewables-alone-cannot-meet-our-energy-needs/

                                            There are also lots of studies, e.g. https://linkinghub.elsevier.com/retrieve/pii/S2542435119302144

                                            • smegforbrains@lemmy.ml
                                              ·
                                              9 months ago

                                              Research into this topic is fairly new, with very few studies published before 2009, but has gained increasing attention in recent years. The majority of studies show that a global transition to 100% renewable energy across all sectors – power, heat, transport and industry – is feasible and economically viable.

                                              https://doi.org/10.1016%2Fj.apenergy.2020.116273

                                              https://link.springer.com/book/10.1007/978-3-030-05843-2

                                              https://yle.fi/uutiset/osasto/news/cheap_safe_100_renewable_energy_possible_before_2050_says_finnish_uni_study/10736252

                                              https://doi.org/10.1016%2Fj.rser.2021.110934

                                              • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                                hexagon
                                                ·
                                                9 months ago

                                                Not sure what you're basing this grand assertion that most studies show the transition is feasible and economically viable. For every study that shows this, I can find you one that shows the opposite. In fact, as you admit, this is a new research topic with a lot of unknowns, and we are in a middle of a global crisis that threatens our whole civilization. Using proven technologies that are known to work seems like a far better thing to do than to experiment in a middle of a crisis.

                                                • smegforbrains@lemmy.ml
                                                  ·
                                                  9 months ago

                                                  That's a valid point. There is no consensus yet. But what's the worst that would happen if we can't achieved this goal in Germany, when we try? We will buy french nuclear power again. But what happens when it works out? Germany will be climate neutral and will be independent of nuclear power. No fission material is required, no uranium mining will be required for power production. So there's the possibility to mitigate the negative impact of uranium mining, while getting rid of the dangers of nuclear power plants and not creating more nuclear waste for future generations to take care of. IMHO that's a great opportunity that we should seize.

                                                  • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                                    hexagon
                                                    ·
                                                    9 months ago

                                                    The worst that will happen is that our civilization collapses because we failed to transition away from the use of fossil fuels. Buying energy from France is the best case scenario, using more coal and other dirty fuels if the transition fails is another very likely scenario. And once again, I'll note that there are alternatives to uranium such as thorium. The only reason uranium is used traditionally is because it doubles up as weapons material. Thorium reactors are cheaper, safer, and don't require water cooling. Why not explore all options, and find a mix of solutions that work reliably. In a situation where there are many unknowns, it's generally best not to put all the eggs in one basket.

                                                    • smegforbrains@lemmy.ml
                                                      ·
                                                      edit-2
                                                      9 months ago

                                                      Hers an interesting article on the dangers of Thorium reactors, including nuclear proliferation concerns: https://www.nature.com/articles/492031a

                                                      Here's an article detailing why nuclear power production is not climate neutral. There a lot of CO2 emissions involved in nuclear power production: https://www.dw.com/en/fact-check-is-nuclear-energy-good-for-the-climate/a-59853315

                                                      Fossil fuel is IMHO no alternative and will only play a minimal role after 2038. Most of the countries, that have pledged to become climate neutral by 2050 will build new nuclear reactors to achieve this. So there will probably be enough energy to go around and Germany can buy such energy if the transition to 100% renewables did not work out as planned. But if it works out we will have a viable way to produce energy in climate neutral way without the hazards that accompany nuclear power production. If this can be proved to work, other countries would be able to emulate this strategy. IMHO this is an opportunity we can not let go to waste.

                                                      • ☆ Yσɠƚԋσʂ ☆@lemmy.ml
                                                        hexagon
                                                        ·
                                                        9 months ago

                                                        Every technology has pros and cons. The rational thing to do is to weigh those against each other instead of simply pointing out what the negatives are. Meanwhile, there are also CO2 emissions involved in producing solar panels or wind turbines.

                                                        The reality is that majority of western countries continue to miss their pledges to transition from fossil fuels. Given past precedent, I would bet against Germany accomplishing its stated goals by 2038. IMHO gambling with the fate of humanity for ideological reasons is unethical.