5 ms·

The alternative isn't coal, the alternative is nuclear.

SquareWheel 8y ago
Both are alternatives. They serve different uses. It is likely we will need both nuclear and solar to finally get off coal.
phyzome 8y ago
Good thing nuclear plants don't produce any toxic waste either.
- wbl 8y ago
  It's all about quantity. The quantity of radioactive waste a nuclear reactor produces is small. It also quickly becomes comparatively harmless.
  - adjkant 8y ago
    I'm not a nuclear expert or anything but can you cite this? Isn't a big negative of nuclear exactly that the waste lasts for so long? What exactly does "relatively harmless" mean?
    - kemayo 8y ago
      I'm too lazy to find a really good source, but here's a quick summary. The spent fuel of a nuclear power plant is a mix of various isotopes, which will decay at different rates. Nuclear decay occurs when radiation is emitted from a nucleus. Thus the more dangerously radioactive stuff decays a lot quicker. Idea is that something which is actively pumping out heat and deadly levels of radiation might become safe(-er) within a few months to years. Getting to the point of "you won't die if you spend an hour in the room with it" is still decades of waiting away, though. And the entire spent fuel mix would take thousands of years to get back to the radiation levels of the original ore we fed into the plant. All that said, a fun-ish comparison I've seen is that coal ash contains fairly high levels of heavy metals like lead and cadmium, which genuinely never become "safe". We have something like 1,500 ash disposal sites in the US which are toxic hellscapes at risk of leaking into the surrounding areas.
      - village-idiot 8y ago
        Coal power plants also pump out a lot more radiation than a nuclear power plant because coal usually contains a fair bit of uranium.
      - phyzome 8y ago
        « Thus the more dangerously radioactive stuff decays a lot quicker. » If it decays very quickly, yes, it's less of a threat (except in case of a spill from the reactor, where people would get exposed to fresh material.) If it decays very slowly... well, the damage just might be spread out over time. I think a case could be made for that, at least... But it's more complicated than that, anyway. Strontium, for instance, is a particular problem because it is similar to calcium, so people's bodies incorporate it into bones. Having it stick around in the body rather than flushing out makes it more dangerous than it would otherwise be. Similar for iodine, which is why nuclear meltdown preparedness programs involve having potassium iodide pills on hand—to try to saturate the body with non-radioactive iodine. So the bioaccumulation potential must be considered as well, because what matters is how long people are in contact with radioisotopes.
    - village-idiot 8y ago
      Nuclear power plants don’t just produce “waste”, they produce uranium that’s mixed with various isotopes that don’t help sustain fission reactions. While all of this waste is “hot” the amount and makeup of the various waste product varies based on reactor design. There are two things that can be done with the waste. First, not all of the nuclear fuel is consumed. The fuel is spent when enough waste has built up to slow fission, which isn’t the same as the fuel being gone. You can re-refine spent rods to reclaim usable fuel and put it back into the reactor. Second, the real dangerous waste isotopes are the cold ones which produce a little radiation but will do so for millennia. So you can shovel those into a subcritical reactor[0] and hurry the stuff along to non-radioactive metals like lead, all while making some electricity to boot. 0: https://en.wikipedia.org/wiki/Subcritical_reactor https://en.wikipedia.org/wiki/Subcritical_reactor
  - Jill_the_Pill 8y ago
    Who says it's just about quantity? Persistence and danger matter immensely, and some waste remains deadly for many thousands of years. It sounds like management of toxic solar waste is merely labor-intensive.
    - wbl 8y ago
      Cadmium lasts forever
      - pfdietz 8y ago
        Good thing the vast majority of PV modules don't use cadmium.
        macawfish 8y ago
        I've been looking all over the comments for information about this... Can you elaborate?
        pfdietz 8y ago
        90+% of PV modules sold are mono or poly crystalline silicon. There is no cadmium involved in that. There are CdTe thin film cells, but they have a small and declining share of the market.
        ThomPete 8y ago
        Here is the full context of that copy and pasted response. http://notrickszone.com/2018/05/23/new-study-solar-module-owners-sitting-on-a-pile-of-hazardous-lead-and-cadmium/#comment-1263379 http://notrickszone.com/2018/05/23/new-study-solar-module-ow...
        deleted 8y ago
        [deleted]
therealdrag0 8y ago
Well right now, the alternative is mostly oil/gas, which is cleaner than coal. Nuclear would be nice, but doesn't seem very likely :(

Both are alternatives. They serve different uses. It is likely we will need both nuclear and solar to finally get off coal.

phyzome 8y ago

Good thing nuclear plants don't produce any toxic waste either.

wbl 8y ago
It's all about quantity. The quantity of radioactive waste a nuclear reactor produces is small. It also quickly becomes comparatively harmless.
- adjkant 8y ago
  I'm not a nuclear expert or anything but can you cite this? Isn't a big negative of nuclear exactly that the waste lasts for so long? What exactly does "relatively harmless" mean?
  - kemayo 8y ago
    I'm too lazy to find a really good source, but here's a quick summary. The spent fuel of a nuclear power plant is a mix of various isotopes, which will decay at different rates. Nuclear decay occurs when radiation is emitted from a nucleus. Thus the more dangerously radioactive stuff decays a lot quicker. Idea is that something which is actively pumping out heat and deadly levels of radiation might become safe(-er) within a few months to years. Getting to the point of "you won't die if you spend an hour in the room with it" is still decades of waiting away, though. And the entire spent fuel mix would take thousands of years to get back to the radiation levels of the original ore we fed into the plant. All that said, a fun-ish comparison I've seen is that coal ash contains fairly high levels of heavy metals like lead and cadmium, which genuinely never become "safe". We have something like 1,500 ash disposal sites in the US which are toxic hellscapes at risk of leaking into the surrounding areas.
    - village-idiot 8y ago
      Coal power plants also pump out a lot more radiation than a nuclear power plant because coal usually contains a fair bit of uranium.
    - phyzome 8y ago
      « Thus the more dangerously radioactive stuff decays a lot quicker. » If it decays very quickly, yes, it's less of a threat (except in case of a spill from the reactor, where people would get exposed to fresh material.) If it decays very slowly... well, the damage just might be spread out over time. I think a case could be made for that, at least... But it's more complicated than that, anyway. Strontium, for instance, is a particular problem because it is similar to calcium, so people's bodies incorporate it into bones. Having it stick around in the body rather than flushing out makes it more dangerous than it would otherwise be. Similar for iodine, which is why nuclear meltdown preparedness programs involve having potassium iodide pills on hand—to try to saturate the body with non-radioactive iodine. So the bioaccumulation potential must be considered as well, because what matters is how long people are in contact with radioisotopes.
  - village-idiot 8y ago
    Nuclear power plants don’t just produce “waste”, they produce uranium that’s mixed with various isotopes that don’t help sustain fission reactions. While all of this waste is “hot” the amount and makeup of the various waste product varies based on reactor design. There are two things that can be done with the waste. First, not all of the nuclear fuel is consumed. The fuel is spent when enough waste has built up to slow fission, which isn’t the same as the fuel being gone. You can re-refine spent rods to reclaim usable fuel and put it back into the reactor. Second, the real dangerous waste isotopes are the cold ones which produce a little radiation but will do so for millennia. So you can shovel those into a subcritical reactor[0] and hurry the stuff along to non-radioactive metals like lead, all while making some electricity to boot. 0: https://en.wikipedia.org/wiki/Subcritical_reactor https://en.wikipedia.org/wiki/Subcritical_reactor
- Jill_the_Pill 8y ago
  Who says it's just about quantity? Persistence and danger matter immensely, and some waste remains deadly for many thousands of years. It sounds like management of toxic solar waste is merely labor-intensive.
  - wbl 8y ago
    Cadmium lasts forever
    - pfdietz 8y ago
      Good thing the vast majority of PV modules don't use cadmium.
      - macawfish 8y ago
        I've been looking all over the comments for information about this... Can you elaborate?
        pfdietz 8y ago
        90+% of PV modules sold are mono or poly crystalline silicon. There is no cadmium involved in that. There are CdTe thin film cells, but they have a small and declining share of the market.
        ThomPete 8y ago
        Here is the full context of that copy and pasted response. http://notrickszone.com/2018/05/23/new-study-solar-module-owners-sitting-on-a-pile-of-hazardous-lead-and-cadmium/#comment-1263379 http://notrickszone.com/2018/05/23/new-study-solar-module-ow...
        deleted 8y ago
        [deleted]

therealdrag0 8y ago

Well right now, the alternative is mostly oil/gas, which is cleaner than coal. Nuclear would be nice, but doesn't seem very likely :(