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> why is nuclear waste dangerous? because there is still loads of energy in it. I though it was because of γ-radiation and long half lives? Are those propertie

> why is nuclear waste dangerous? because there is still loads of energy in it. I though it was because of γ-radiation and long half lives? Are those properties unique to matter with high energy potential?

KGIII 9y ago
I will try to explain it as best as I can. Radioactive material decays as particles are emitted. If it has a long half-life, that pretty much means that the energy is being released rather slowly. In other words, just don't go poking at it and you'll be fine. On the othe hand, stuff with a short half-life means that atoms are decaying rapidly. Particles are being knocked off with great rapidity. That stuff is much more dangerous, in the now. It is transferring energy, in a harmful form, quickly. A long half-life means don't go poking at it for a while. A short half-life means you probably should consider containing it really well. We store both safely because we know people like to poke stuff, and it is harmful. It's just that the scary long half-lives only tell part of the story and many people seem to think those are the more problematic. Disclaimer, I'm a mathematician, not a physicist. However, I've taken a whole lot of physics courses. Someone can probably explain this better than I.
- nothrabannosir 9y ago
  [Same here] From what I remember, the energy released by γ-radiation is quite low. I'm still not convinced that just because something emits γ-radiation, short or long half life, it has an inherently meaningful energy potential. α- and β-radiation: sure. But γ? It's harmful to humans for very different reasons than fissile material is a useful energy source, isn't it? Or am I completely misremembering this all?
  - gaius 9y ago
    Correlation is not causation sure. But "spent" nuclear fuel has plenty of energy left in it that a breeder can extract.
deleted 9y ago
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dfox 9y ago
The energy of the radiated γ-photons has to come from somewhere. In the first approximation the fission reactor is device for releasing this energy faster while converting it into more mamageable form. (Pure fission and Teller-Ulam bombs are about releasing said energy as fast and as completely as possible)

KGIII 9y ago

I will try to explain it as best as I can. Radioactive material decays as particles are emitted. If it has a long half-life, that pretty much means that the energy is being released rather slowly. In other words, just don't go poking at it and you'll be fine. On the othe hand, stuff with a short half-life means that atoms are decaying rapidly. Particles are being knocked off with great rapidity. That stuff is much more dangerous, in the now. It is transferring energy, in a harmful form, quickly. A long half-life means don't go poking at it for a while. A short half-life means you probably should consider containing it really well. We store both safely because we know people like to poke stuff, and it is harmful. It's just that the scary long half-lives only tell part of the story and many people seem to think those are the more problematic. Disclaimer, I'm a mathematician, not a physicist. However, I've taken a whole lot of physics courses. Someone can probably explain this better than I.

nothrabannosir 9y ago
[Same here] From what I remember, the energy released by γ-radiation is quite low. I'm still not convinced that just because something emits γ-radiation, short or long half life, it has an inherently meaningful energy potential. α- and β-radiation: sure. But γ? It's harmful to humans for very different reasons than fissile material is a useful energy source, isn't it? Or am I completely misremembering this all?
- gaius 9y ago
  Correlation is not causation sure. But "spent" nuclear fuel has plenty of energy left in it that a breeder can extract.

deleted 9y ago

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dfox 9y ago

The energy of the radiated γ-photons has to come from somewhere. In the first approximation the fission reactor is device for releasing this energy faster while converting it into more mamageable form. (Pure fission and Teller-Ulam bombs are about releasing said energy as fast and as completely as possible)