• ✺roguetrick✺@lemmy.world
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    14 days ago

    Run low on water, stop reaction. Fission products keep getting hot even though reaction stopped. Not enough water to cool them off. Shit.

    • Kaelygon@lemmy.world
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      13 days ago

      thankfully modern ones like molten salt reactors have passive safety, where they stop the reaction if overheating occurs.
      edit: My mistake, there’s no active commercial molten salt reactors.
      But nuclear power is very safe nowadays because of the multiple fail-safes, which some can still be passive like emergency cooling.
      I much rather get electricity from magic rocks than destroying rain forest in developing countries drilling oil, gas or mining coal.
      The biggest risk in nuclear is environmental disasters like in Fukushima’s case, which is the last significant nuclear incident in past 13 years

      • Synapse@lemmy.world
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        14 days ago

        Ah yes, the passive safety of the molten salt spontaneously catching on fire when in contact with air and can’t be put out with water.

      • ✺roguetrick✺@lemmy.world
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        14 days ago

        You can’t stop decay heat. It’s just molton salt reactors can operate at much higher temperatures and if it loses active cooling passive cooling with just air and infrared radiation while the salt passively circulates could be enough.

      • PieMePlenty@lemmy.world
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        14 days ago

        Isn’t molten salt just energy storage? Heat up salt when you have excess of energy, take heat out when you need it. The worst disaster there is just the container melting.

        • Agent641@lemmy.world
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          13 days ago

          No, there are molten salt thermal batteries, but they aren’t the same as molten salt nuclear reactor. In a nuclear reactor the fissile material is dissolved in the salt for some reason, and the molten salt acts as a moderator or something. Apparently its safe because if the reactor power fails, the salt ‘freezes’ which prevents fission from occurring. Seems like complex extra steps to me but what do I know.

          • JATth@lemmy.world
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            13 days ago

            MSRs have negative temperature reactivity coefficient and outlet temps around 700C at atm pressure. PWR is at measly 300C and 150 Bar.

            If all control is lost, the salt expands as it heats up pushing the expanded volume out from the reactor core. The fission stops once the fuel is leaves the core region where the moderator is. Reverse is also true: you pull heat off from the loop, so the fuel-salt becomes denser, increasing reactivity. MSRs can naturally “follow” the load, if done right.

      • humanspiral@lemmy.ca
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        13 days ago

        there’s no active commercial molten salt reactors.

        Experimental ones were all shut down within 5-10 years because corrosion makes them uneconomical to repair.

        Fukushima’s case, which is the last significant nuclear incident in past 13 years

        Zaporizhzhia (shutdown with IAEA concerns but may not fully report any emission releases) in Ukraine has military attacks against it, with intent of fundraising and politically blaming a disaster on the side that weapons providers, and the media they own, love to hate. Our media normalizes civil war as a response to Netanyahu not having his favorite ruler appointed.

    • Rakonat@lemmy.world
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      13 days ago

      Turn water back on suddenly and realize what happens when water touches an object many times warmer than it’s boiling point.