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The author says the waste isn't liquid, but also says that spent fuel rods are cooled in pools for several years. Does the water not become irradiated in that t

The author says the waste isn't liquid, but also says that spent fuel rods are cooled in pools for several years. Does the water not become irradiated in that time?

Aeolun 4y ago
Does your cup of water become irradiated from having a hot spoon stuck in it? I think the water is mostly safe. At worst the water will have little slivers of radioactive material floating in it but that’s only if something already went wrong, so I imagine it’s cleaned before being discharged. Ultimately you can also cool it down and reuse it, so you might not need all that much water relatively speaking.
- fragmede 4y ago
  My hot spoon isn't made up of uranium and didn't come out of a nuclear reactor, and isn't radioactive, so I'm not sure how that addresses GP's concerns.
  - LarryMullins 4y ago
    Your hot spoon is in fact radioactive, emitting thermal radiation. Thermal radiation doesn't make things it hits radioactive. Neither does your microwave oven or even gamma radiation. Radioactivity can be induced in things by neutron radiation, but not EM radiation. It is safe to eat food which has been irradiated with gamma radiation, and chances are you have many times before (it is fairly common for dried spices and herbs to be irradiated for preservation purposes.)
    - idlewords 4y ago
      Things that emit thermal radiation are not radioactive. An easy way to conceptualize it for stuff here on Earth is that radioactivity involves stuff flying out of the nucleus of an atom, while other forms of radiation do not.
      - LarryMullins 4y ago
        Thermal radiation is in fact emitted from the nucleus of atoms; all matter emits black body radiation. The reason hot things generally aren't considered radioactive is because that would pull literally all matter into the discussion. But that wasn't the point being made here. The point being made with the hot spoon example is that EM radiation doesn't make other things radioactive (except insofar as it heats things up). This is equally true of gamma radiation as thermal radiation. Thermal radiation and gamma radiation can both cause harm directly, but neither will make other things radioactive. That's why it's completely safe to eat food that was sterilized with gamma radiation intense enough to kill you outright.
        idlewords 4y ago
        I think you may be confused about the distinction between radioactivity and black body radiation. The fact that gamma rays, microwaves, visible light and so on are all on a spectrum doesn't mean that every EM emitter is radioactive.
        LarryMullins 4y ago
        Whether or not you want to apply the term "radioactive" to a black body emitter is completely beside the point, which is that EM radiation doesn't make things radioactive. Your objection is to the use of a word, not the physics, so I think this discussion has run its course.
        philipkglass 4y ago
        At high enough photon energy, electromagnetic radiation actually can make things radioactive. The general term is "photonuclear reactions." Here's an example: "Photonuclear production of medical isotopes 62,64Cu using intense laser-plasma electron source" https://aip.scitation.org/doi/10.1063/1.5100925 https://aip.scitation.org/doi/10.1063/1.5100925
- denton-scratch 4y ago
  > so I imagine it’s cleaned before being discharged. There's plutonium dust in the silt under the Irish Sea, off the coast from Sellafield. Inhaling a single particle of plutonium dust (much smaller than a 'sliver') can kill you. I think your imagination has misled you.
  - Aeolun 4y ago
    Just because it’s ‘cleaned’ doesn’t mean it’s perfectly clean after doing so.
idlewords 4y ago
You need a high intensity neutron flux to make water radioactive, which spent fuel doesn't provide. The kinds of radiation you find in a cooling pond won't activate water, so all you have to worry about is stuff potentially dissolving into it. Here's a paper on how water gets activated when it cools a nuclear core (which does have massive numbers of neutrons zipping around): https://doi.org/10.1016/j.pnucene.2019.103042 https://doi.org/10.1016/j.pnucene.2019.103042
tromp 4y ago
Answered here: https://www.quora.com/Does-water-become-radioactive-after-being-used-as-coolant-in-nuclear-power-plant https://www.quora.com/Does-water-become-radioactive-after-be...
jaywalk 4y ago
The water does not become irradiated: https://physics.stackexchange.com/questions/101433/why-doesnt-a-nuclear-fuel-pool-become-irradiated https://physics.stackexchange.com/questions/101433/why-doesn...
LarryMullins 4y ago
There are two main ways that something may become radioactive, being contaminated with little pieces of something radioactive (for instance nuclear fallout), or through neutron activation, in which neutron radiation creates radioactive isotopes in whatever it hits. Assuming the fuel rods have intact cladding, then the first shouldn't be happening in a cooling pond. However the fuel rods do give off neutron radiation, and a small amount of the hydrogen in the water is turned into tritium by that neutron radiation. Tritium is a weak beta emitter, it could harm you if you drank a lot of it. But it's not a long-term problem because it has a half life of 12 years.
thescriptkiddie 4y ago
The term you are looking for is "neutron activation". Irradiation alone doesn't make things radioactive, they have to capture fast neutrons specifically in order to be transmuted into unstable isotopes. Hydrogen and Oxygen are less susceptible to this than heavier elements which is why it is so hard to make heavy water. It does happen inside running nuclear reactors but spent fuel doesn't give off enough neutrons for it to be an issue.

The author says the waste isn't liquid, but also says that spent fuel rods are cooled in pools for several years. Does the water not become irradiated in that time?

Aeolun 4y ago

Does your cup of water become irradiated from having a hot spoon stuck in it? I think the water is mostly safe. At worst the water will have little slivers of radioactive material floating in it but that’s only if something already went wrong, so I imagine it’s cleaned before being discharged. Ultimately you can also cool it down and reuse it, so you might not need all that much water relatively speaking.

fragmede 4y ago
My hot spoon isn't made up of uranium and didn't come out of a nuclear reactor, and isn't radioactive, so I'm not sure how that addresses GP's concerns.
- LarryMullins 4y ago
  Your hot spoon is in fact radioactive, emitting thermal radiation. Thermal radiation doesn't make things it hits radioactive. Neither does your microwave oven or even gamma radiation. Radioactivity can be induced in things by neutron radiation, but not EM radiation. It is safe to eat food which has been irradiated with gamma radiation, and chances are you have many times before (it is fairly common for dried spices and herbs to be irradiated for preservation purposes.)
  - idlewords 4y ago
    Things that emit thermal radiation are not radioactive. An easy way to conceptualize it for stuff here on Earth is that radioactivity involves stuff flying out of the nucleus of an atom, while other forms of radiation do not.
    - LarryMullins 4y ago
      Thermal radiation is in fact emitted from the nucleus of atoms; all matter emits black body radiation. The reason hot things generally aren't considered radioactive is because that would pull literally all matter into the discussion. But that wasn't the point being made here. The point being made with the hot spoon example is that EM radiation doesn't make other things radioactive (except insofar as it heats things up). This is equally true of gamma radiation as thermal radiation. Thermal radiation and gamma radiation can both cause harm directly, but neither will make other things radioactive. That's why it's completely safe to eat food that was sterilized with gamma radiation intense enough to kill you outright.
      - idlewords 4y ago
        I think you may be confused about the distinction between radioactivity and black body radiation. The fact that gamma rays, microwaves, visible light and so on are all on a spectrum doesn't mean that every EM emitter is radioactive.
        LarryMullins 4y ago
        Whether or not you want to apply the term "radioactive" to a black body emitter is completely beside the point, which is that EM radiation doesn't make things radioactive. Your objection is to the use of a word, not the physics, so I think this discussion has run its course.
        philipkglass 4y ago
        At high enough photon energy, electromagnetic radiation actually can make things radioactive. The general term is "photonuclear reactions." Here's an example: "Photonuclear production of medical isotopes 62,64Cu using intense laser-plasma electron source" https://aip.scitation.org/doi/10.1063/1.5100925 https://aip.scitation.org/doi/10.1063/1.5100925
denton-scratch 4y ago
> so I imagine it’s cleaned before being discharged. There's plutonium dust in the silt under the Irish Sea, off the coast from Sellafield. Inhaling a single particle of plutonium dust (much smaller than a 'sliver') can kill you. I think your imagination has misled you.
- Aeolun 4y ago
  Just because it’s ‘cleaned’ doesn’t mean it’s perfectly clean after doing so.

idlewords 4y ago

You need a high intensity neutron flux to make water radioactive, which spent fuel doesn't provide. The kinds of radiation you find in a cooling pond won't activate water, so all you have to worry about is stuff potentially dissolving into it. Here's a paper on how water gets activated when it cools a nuclear core (which does have massive numbers of neutrons zipping around): https://doi.org/10.1016/j.pnucene.2019.103042 https://doi.org/10.1016/j.pnucene.2019.103042

tromp 4y ago

Answered here: https://www.quora.com/Does-water-become-radioactive-after-being-used-as-coolant-in-nuclear-power-plant https://www.quora.com/Does-water-become-radioactive-after-be...

jaywalk 4y ago

The water does not become irradiated: https://physics.stackexchange.com/questions/101433/why-doesnt-a-nuclear-fuel-pool-become-irradiated https://physics.stackexchange.com/questions/101433/why-doesn...

LarryMullins 4y ago

There are two main ways that something may become radioactive, being contaminated with little pieces of something radioactive (for instance nuclear fallout), or through neutron activation, in which neutron radiation creates radioactive isotopes in whatever it hits. Assuming the fuel rods have intact cladding, then the first shouldn't be happening in a cooling pond. However the fuel rods do give off neutron radiation, and a small amount of the hydrogen in the water is turned into tritium by that neutron radiation. Tritium is a weak beta emitter, it could harm you if you drank a lot of it. But it's not a long-term problem because it has a half life of 12 years.

thescriptkiddie 4y ago

The term you are looking for is "neutron activation". Irradiation alone doesn't make things radioactive, they have to capture fast neutrons specifically in order to be transmuted into unstable isotopes. Hydrogen and Oxygen are less susceptible to this than heavier elements which is why it is so hard to make heavy water. It does happen inside running nuclear reactors but spent fuel doesn't give off enough neutrons for it to be an issue.