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Joined 2 years ago
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Cake day: March 22nd, 2024

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  • literal tens of tons half-burnt uranium that takes way too long to decay to safe level.

    I mean, breeder reactors? Also it’s still not that much, especially compared to the economics of everything else.

    Anyway, what I didn’t realize was these are 14 MeV neutrons, unless they crack D-D fusion. That’s… very different. That’s more destructive, and harder to deal with, than fission neutrons.


    …To expand on this, I’m somewhat skeptical of all nuclear now. It’s fine, it works great, fusion is a noble pursuit. But it just takes too long to set up to stave off carbon emissions.



  • I just realized…

    I don’t like fusion.

    They say it’s clean, but 14.1 MeV neutrons are no joke.

    https://en.wikipedia.org/wiki/Neutron_temperature#Fast

    14.1 MeV neutrons have about 10 times as much energy as fission neutrons, and they are very effective at fissioning even non-fissile heavy nuclei. These high-energy fissions also produce more neutrons on average than fissions by lower-energy neutrons. D–T fusion neutron sources, such as proposed tokamak power reactors, are therefore useful for transmutation of transuranic waste. 14.1 MeV neutrons can also produce neutrons by knocking them loose from nuclei.

    On the other hand, these very high-energy neutrons are less likely to simply be captured without causing fission or spallation. For these reasons, nuclear weapon design extensively uses D–T fusion 14.1 MeV neutrons to cause more fission. Fusion neutrons are able to cause fission in ordinarily non-fissile materials, such as depleted uranium (uranium-238), and these materials have been used in the jackets of thermonuclear weapons. Fusion neutrons also can cause fission in substances that are unsuitable or difficult to make into primary fission bombs, such as reactor grade plutonium. This physical fact thus causes ordinary non-weapons grade materials to become of concern in certain nuclear proliferation discussions and treaties.

    How are reaction chambers supposed to deal with that? It’s not very sustainable if the whole assembly breaks down and turns radioactive over time.