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> coal ash is more radioactive than nuclear waste, says Scientific American. This isn't true in any reasonable sense, and SA retract the claim in a footnote. B

> coal ash is more radioactive than nuclear waste, says Scientific American. This isn't true in any reasonable sense, and SA retract the claim in a footnote. But nuclear plants produce so much less waste than coal plants that overall, they release less radiation joule for joule.

virgilp 7y ago
> This isn't true in any reasonable sense, > overall, they release less radiation joule for joule. How is that not a "reasonable sense"? Less radiation joule per joule seems to me like a reasonable measure as "less radioactive overall"
- dmurray 7y ago
  At the point where it's already waste, you don't really care about the energy that was produced from it, possibly years or thousands of years ago.
  - yongjik 7y ago
    If one power plant creates 1000t of waste, and another creates 10000t of waste while providing the same amount of electricity, I think we can reasonably say that the second generates 10x more waste. "Well, if you pick just one ton of waste from either plant it's the same waste!" is technically true, but it's neither here nor there. (Of course in case of nuclear vs. coal it's a bit more complicated because the waste products are not the same, but I still think we can reasonably compare waste per energy.)
    - deleted 7y ago
      [deleted]
    - philliphaydon 7y ago
      If bill gates venture into power pans out there won’t be nuclear waste at all it seems.
      - soperj 7y ago
        There are already plants that can do what he's proposing, like the CANDU reactor. It looks like they've taken some ideas directly from that reactor, so it looks pretty conspicuous that they never mention it.
        philliphaydon 7y ago
        I don't know much about this stuff. Just watched that doco on Netflix, inside bills brain. It was the first I had heard of Nuclear power using depleted uranium, and that America apparently has enough depleted uranium to power the US for ~140 years or something. I don't know why this isn't being pushed harder if it's safer and cleans up some of this waste.
        soperj 7y ago
        Yeah, I watched the whole thing too. They leave out so much stuff, like that Paul Allen left the company because Bill & Steve Ballmer tried to dilute his shares when he had cancer, or that they actually bought DOS (the doco makes it look like they were working their ass off to build it). CANDU reactors are Canadian, they use heavy water. They've been around for 50 years, people don't use them because they can't be used to make nuclear weapons. All the reators in Canada are these style.
        selectodude 7y ago
        We just need to find a way, way cheaper source of heavy water.
        jabl 7y ago
        Wait, what, no! CANDU is a thermal water moderated reactor, albeit moderated with heavy water rather than light water, allowing it to use natural uranium instead of enriched (as Canada didn't have enrichment capability and didn't want to depend on other nations). And it's a pressure tube design, meaning the high pressure water is kept in a bunch of tubes rather than having one big pressure vessel like most light water reactors (again, because Canada didn't have heavy forges required to produce traditional reactor vessels). What Bill Gates funded is a company called Terrapower that is making a sodium cooled fast breeder. Very different from CANDU. Fast breeders are a pretty cool concept, but they and the reprocessing technology for closing the fuel cycle isn't as mature as light water reactors.
    - lmm 7y ago
      If the 1000t is radioactive at 5Bq/Kg and the 10000t is radioactive at 2Bq/Kg, it's at best confusing to say the second plant's waste is "more radioactive".
  - baddox 7y ago
    Surely you usually do care, because usually the discussion is about the best way to generate a given amount of energy.
- deleted 7y ago
  [deleted]
- elihu 7y ago
  Saying that coal ash is "more radioactive than nuclear waste" is too ambiguous. There are many kinds of nuclear waste with varying degrees of radioactivity. I assume there are also variations in the degree of radioactivity in coal ash. It might be meaningful to say that a particular kind of coal ash is more radioactive than a particular kind of nuclear waste, but without that context it's a meaningless comparison.
- Retric 7y ago
  The coal is as radioactive as the ash, thus these power plants are not creating any new radioactive waste.
  - joelvalleroy 7y ago
    Does that apply also to nuclear fuel? The byproducts of fission with uranium is less radioactive, or has a shorter half life, if I recall.
    - Retric 7y ago
      Short half lives are what make something radioactive. It's not 1:1 but basically take the amount of material / half life > how much radiation is being released. Uranium 238 is extremely stable with a half life of 4.468 billion years, and the more active uranium 235 still has a half life of 0.7 billion years. Which is why they survived geologic timescales from earths formation. Strontium-90 by comparison is produced in a nuclear reactor and has a half life of 28.8 years making it vastly more nasty. Further, while nuclear waste is incredibly nasty stuff, high neutron fluxes also turn the walls etc radioactive though to a less extreme extent.
8bitsrule 7y ago
I don't think so either ... and SA should never had put that in print. Anyway, there's no argument, just numbers. The measure of 'more radioactive than' is Bq/kg. (Total radiation? who releases those numbers? where's the transparency?) According to the following article (and a couple I'm not citing), coal fly ash counts are on the order of 250-1000 Bq/kg. https://link.springer.com/article/10.1007/s10967-006-6966-1 https://link.springer.com/article/10.1007/s10967-006-6966-1 Specifically, concentrated (fly ash) measures: "263 to 950 Bq·kg−1 for 238U, from 142 to 605 Bq·kg−1 for 226Ra, from 133 to 428 Bq·kg−1 for 210Pb, from 27 to 68 Bq·kg−1 for 228Ra and from 204 to 382 Bq·kg−1 for 40K" Anyone who cares to is welcome to cite the Bq/kg numbers for waste from nuclear plants. Go ahead, pick some. I think you'll find they are higher. And most coal doesn't contain any Pu.
- vihren 7y ago
  We are not discussing nuclear waste here. It is highly concentrated and disposed of in the end of the fuel cycle. What you should be comparing with is the radioactivity that is released in the environment during the operation of the plant. That is mostly Tritium and isotopes of Xenon, definitely no heavy metals. Tritium is a very low energy beta emitter and is mostly harmless. Xenon is a noble gas and a beta emitter, so again not very harmful. The WHO guidelines on alpha emitters (all elements you cite that are contained in fly ash) is 1 Bq/l in drinking water. So depending on how and where this ash goes to, you can definitely cause some significant damage with it.
- makomk 7y ago
  For context, that seems to make coal ash about as radioactive as granite based on these figures for the latter: https://www.sciencedirect.com/science/article/pii/S1687850717300870 https://www.sciencedirect.com/science/article/pii/S168785071...
BurningFrog 7y ago
I think the real valid point is that nuclear waste is stored in a safe location, while coal waste is stored in the atmosphere and thus partially in our lungs.
- stefs 7y ago
  > while coal waste is stored in the atmosphere and thus partially in our lungs can't argue with that > nuclear waste is stored in a safe location so, that's part of the reason many people i know are still very suspicious about nuclear power even though they know _intellectually_ that it's (supposed to be) safer than some of the alternatives. nuclear waste used to be dumped into the ocean, because back then we thought that would be safe. now it's stored in places that are deemed (earthquake-) safe until an earthquake (or a tsunami) hits. next we outsource the storage to private companies as those are cheaper and act suprised when we learn that they were skimping on manpower, maintenance and safety protocols when trying to cut costs and containers are leaking into the ground water. it's the same as nuclear power plants. they're always perfectly secure until something unforseen happens or they've been secure for so long people get neglient.
arcticfox 7y ago
Joule for Joule radioactivity seems like the only reasonable sense. Who cares if it's one drop of death or a pool full of lightly toxic waste? You could easily just dilute the drop to arrive at a similar but less toxic pool (if you wanted to, for some reason).
philipkglass 7y ago
But nuclear plants produce so much less waste than coal plants that overall, they release less radiation joule for joule. Even that isn't quite accurate. Reactors release more radiation, but mostly in the form of elements that don't bioconcentrate into the food supply, so that the effective exposure of the human population is lower. I wrote a long comment a couple of years ago discussing the original article that Scientific American paraphrased for this report: https://news.ycombinator.com/item?id=14466887 https://news.ycombinator.com/item?id=14466887

virgilp 7y ago

> This isn't true in any reasonable sense, > overall, they release less radiation joule for joule. How is that not a "reasonable sense"? Less radiation joule per joule seems to me like a reasonable measure as "less radioactive overall"

dmurray 7y ago
At the point where it's already waste, you don't really care about the energy that was produced from it, possibly years or thousands of years ago.
- yongjik 7y ago
  If one power plant creates 1000t of waste, and another creates 10000t of waste while providing the same amount of electricity, I think we can reasonably say that the second generates 10x more waste. "Well, if you pick just one ton of waste from either plant it's the same waste!" is technically true, but it's neither here nor there. (Of course in case of nuclear vs. coal it's a bit more complicated because the waste products are not the same, but I still think we can reasonably compare waste per energy.)
  - deleted 7y ago
    [deleted]
  - philliphaydon 7y ago
    If bill gates venture into power pans out there won’t be nuclear waste at all it seems.
    - soperj 7y ago
      There are already plants that can do what he's proposing, like the CANDU reactor. It looks like they've taken some ideas directly from that reactor, so it looks pretty conspicuous that they never mention it.
      - philliphaydon 7y ago
        I don't know much about this stuff. Just watched that doco on Netflix, inside bills brain. It was the first I had heard of Nuclear power using depleted uranium, and that America apparently has enough depleted uranium to power the US for ~140 years or something. I don't know why this isn't being pushed harder if it's safer and cleans up some of this waste.
        soperj 7y ago
        Yeah, I watched the whole thing too. They leave out so much stuff, like that Paul Allen left the company because Bill & Steve Ballmer tried to dilute his shares when he had cancer, or that they actually bought DOS (the doco makes it look like they were working their ass off to build it). CANDU reactors are Canadian, they use heavy water. They've been around for 50 years, people don't use them because they can't be used to make nuclear weapons. All the reators in Canada are these style.
      - selectodude 7y ago
        We just need to find a way, way cheaper source of heavy water.
      - jabl 7y ago
        Wait, what, no! CANDU is a thermal water moderated reactor, albeit moderated with heavy water rather than light water, allowing it to use natural uranium instead of enriched (as Canada didn't have enrichment capability and didn't want to depend on other nations). And it's a pressure tube design, meaning the high pressure water is kept in a bunch of tubes rather than having one big pressure vessel like most light water reactors (again, because Canada didn't have heavy forges required to produce traditional reactor vessels). What Bill Gates funded is a company called Terrapower that is making a sodium cooled fast breeder. Very different from CANDU. Fast breeders are a pretty cool concept, but they and the reprocessing technology for closing the fuel cycle isn't as mature as light water reactors.
  - lmm 7y ago
    If the 1000t is radioactive at 5Bq/Kg and the 10000t is radioactive at 2Bq/Kg, it's at best confusing to say the second plant's waste is "more radioactive".
- baddox 7y ago
  Surely you usually do care, because usually the discussion is about the best way to generate a given amount of energy.
deleted 7y ago
[deleted]
elihu 7y ago
Saying that coal ash is "more radioactive than nuclear waste" is too ambiguous. There are many kinds of nuclear waste with varying degrees of radioactivity. I assume there are also variations in the degree of radioactivity in coal ash. It might be meaningful to say that a particular kind of coal ash is more radioactive than a particular kind of nuclear waste, but without that context it's a meaningless comparison.
Retric 7y ago
The coal is as radioactive as the ash, thus these power plants are not creating any new radioactive waste.
- joelvalleroy 7y ago
  Does that apply also to nuclear fuel? The byproducts of fission with uranium is less radioactive, or has a shorter half life, if I recall.
  - Retric 7y ago
    Short half lives are what make something radioactive. It's not 1:1 but basically take the amount of material / half life > how much radiation is being released. Uranium 238 is extremely stable with a half life of 4.468 billion years, and the more active uranium 235 still has a half life of 0.7 billion years. Which is why they survived geologic timescales from earths formation. Strontium-90 by comparison is produced in a nuclear reactor and has a half life of 28.8 years making it vastly more nasty. Further, while nuclear waste is incredibly nasty stuff, high neutron fluxes also turn the walls etc radioactive though to a less extreme extent.

8bitsrule 7y ago

I don't think so either ... and SA should never had put that in print. Anyway, there's no argument, just numbers. The measure of 'more radioactive than' is Bq/kg. (Total radiation? who releases those numbers? where's the transparency?) According to the following article (and a couple I'm not citing), coal fly ash counts are on the order of 250-1000 Bq/kg. https://link.springer.com/article/10.1007/s10967-006-6966-1 https://link.springer.com/article/10.1007/s10967-006-6966-1 Specifically, concentrated (fly ash) measures: "263 to 950 Bq·kg−1 for 238U, from 142 to 605 Bq·kg−1 for 226Ra, from 133 to 428 Bq·kg−1 for 210Pb, from 27 to 68 Bq·kg−1 for 228Ra and from 204 to 382 Bq·kg−1 for 40K" Anyone who cares to is welcome to cite the Bq/kg numbers for waste from nuclear plants. Go ahead, pick some. I think you'll find they are higher. And most coal doesn't contain any Pu.

vihren 7y ago
We are not discussing nuclear waste here. It is highly concentrated and disposed of in the end of the fuel cycle. What you should be comparing with is the radioactivity that is released in the environment during the operation of the plant. That is mostly Tritium and isotopes of Xenon, definitely no heavy metals. Tritium is a very low energy beta emitter and is mostly harmless. Xenon is a noble gas and a beta emitter, so again not very harmful. The WHO guidelines on alpha emitters (all elements you cite that are contained in fly ash) is 1 Bq/l in drinking water. So depending on how and where this ash goes to, you can definitely cause some significant damage with it.
makomk 7y ago
For context, that seems to make coal ash about as radioactive as granite based on these figures for the latter: https://www.sciencedirect.com/science/article/pii/S1687850717300870 https://www.sciencedirect.com/science/article/pii/S168785071...

BurningFrog 7y ago

I think the real valid point is that nuclear waste is stored in a safe location, while coal waste is stored in the atmosphere and thus partially in our lungs.

stefs 7y ago
> while coal waste is stored in the atmosphere and thus partially in our lungs can't argue with that > nuclear waste is stored in a safe location so, that's part of the reason many people i know are still very suspicious about nuclear power even though they know _intellectually_ that it's (supposed to be) safer than some of the alternatives. nuclear waste used to be dumped into the ocean, because back then we thought that would be safe. now it's stored in places that are deemed (earthquake-) safe until an earthquake (or a tsunami) hits. next we outsource the storage to private companies as those are cheaper and act suprised when we learn that they were skimping on manpower, maintenance and safety protocols when trying to cut costs and containers are leaking into the ground water. it's the same as nuclear power plants. they're always perfectly secure until something unforseen happens or they've been secure for so long people get neglient.

arcticfox 7y ago

Joule for Joule radioactivity seems like the only reasonable sense. Who cares if it's one drop of death or a pool full of lightly toxic waste? You could easily just dilute the drop to arrive at a similar but less toxic pool (if you wanted to, for some reason).

philipkglass 7y ago

But nuclear plants produce so much less waste than coal plants that overall, they release less radiation joule for joule. Even that isn't quite accurate. Reactors release more radiation, but mostly in the form of elements that don't bioconcentrate into the food supply, so that the effective exposure of the human population is lower. I wrote a long comment a couple of years ago discussing the original article that Scientific American paraphrased for this report: https://news.ycombinator.com/item?id=14466887 https://news.ycombinator.com/item?id=14466887