10 ms·

A tale of two particles: Not all radioactivity is risky or harmful

58 points by jseliger 4y ago

paulkrush 4y ago
Two points really stand out here. 1.) Nuclear waste can be handled by hand after 600 years. 2.) Coal plant: 3-6 Million tons of toxic ash in its operating life, not to mention 110 million tons of CO vs 1000 tons of nuclear waste.
- sneakerblack 4y ago
  Something that the article didn't mention is that coal plants also produce radiation, and because of the lack of protection against it, the average dose of yearly radiation you get living near a coal plant is actually higher than living near a nuclear plant. That said, the repercussions of a major disaster are a lot lower with a coal plant than with a nuclear plant. And, as always, relevant XKCD: https://xkcd.com/radiation/ https://xkcd.com/radiation/
  - fsh 4y ago
    This factoid about coal power plants is often repeated, but I have my doubts about the accuracy. It seems to be based on a 44 year old paper [1] which comes to the conclusion that the radiation dose you get from living near a coal plant is on the same order of magnitude as the one from living near a BWR or PWR (Table 5 in the reference). However, emissions regulations for power plants (fossil or nuclear) are surely very different in 2022 than they were in 1978. [1] https://www.science.org/doi/10.1126/science.202.4372.1045 https://www.science.org/doi/10.1126/science.202.4372.1045
- rapjr9 4y ago
  Two things that are glossed over are "Others can be processed into excellent nuclear fuel, although currently this is not quite economic, in part because the fission product decay makes handling the used fuel so difficult." So we don't know how to do this yet, and processing spent fuel rods also produces a lot of toxic and radioactive byproducts that are also difficult to handle, take a look at this Superfund site: https://nmisite.org/site-history/ https://nmisite.org/site-history/ The other thing the article does not even mention is meltdowns of operating plants and attacks on or natural disasters affecting dry cask storage and reprocessing plants. Sure, you have to eat or breath the material for it to be dangerous after 600 years, but if a plant melts down or an idiot blows up the spent fuel then it gets into water, food, soil and the air and everyone ingests it, for a very long time thereafter, BEFORE the 600 years is up. Also, keeping something safe for 600 years is something nobody has ever done. Most societies don't even last 600 years. Look at what a mess we made of it just 50 years ago: https://www.latimes.com/environment/story/2020-07-01/us-says-nuclear-waste-safe-marshall-islands-runit-dome https://www.latimes.com/environment/story/2020-07-01/us-says... And here is a list of how well we've handled nuclear materials so far: "11 Nuclear meltdowns and Disasters" https://www.cnbc.com/2011/03/16/11-Nuclear-Meltdowns-and-Disasters.html https://www.cnbc.com/2011/03/16/11-Nuclear-Meltdowns-and-Dis... The Zaporizhzhia nuclear plant in Ukraine is currently being shelled. Again. So it seems world peace is a prerequisite, I'd like to see the plan for that. After we've achieved world peace then the 600 year containment experiments can start and we can figure out how to get our engineering to 99.99999% reliability. Smaller, less dangerous, and inherently safer reactor designs are being tried, maybe one of those will work well enough to be able to ramp up nuclear power, but the technology in current use is not good enough.
  - PaulHoule 4y ago
    Aqueous reprocessing of nuclear fuel is a technology that's been mastered by many nations. Fabricating quality MOX that be fed back into reactors is something that France and Russia have succeeded at and the US and UK have failed at. That said, there might be some other way to make MOX, or some other fuel formulation based on molten salts, metal fuel, nitrides, carbides, etc. As for economics a big problem is that the LWR works at low temperatures and requires a huge steam turbine and huge heat exchangers. This is apart from the problem that large LWR construction projects frequently go over schedule and budget by a large margin. There is some hope that a smaller reactor like China's ACP-100 can find some simplification at small scale that makes up for the diseconomies of small scale and avoids the project management problems but it will take some kind of water-free reactor that operates at higher temperatures for nuclear to be competitive with natural gas.
    - deleted 4y ago
      [deleted]
    - credit_guy 4y ago
      > Fabricating quality MOX that be fed back into reactors MOX can be fed back only once. After that too much Pu-240 accumulates, and that's a non-fissile element that absorbs a lot of neutrons, so it's a neutron poison (see [1]). Pu-240 can't be separated from Pu-239, except using the same methods to separate U-235 from U-238 (but more difficult, since the relative atomic mass difference is much smaller). If you get into the business of isotope separation, you might as well enrich Uranium. [1] https://en.wikipedia.org/wiki/MOX_fuel#Spent_MOX_fuel https://en.wikipedia.org/wiki/MOX_fuel#Spent_MOX_fuel
      - PaulHoule 4y ago
        With a fast reactor you can keep the cycle going. Russia is recycling MOX with the BN-800 fast reactor. The U.S. did it too with the FFTF but the FFTF dumped the heat to the air without trying to produce power. Oddly, this makes the FFTF look more like a future fast reactor because the heat exchanger for the FFTF looks more like the heat exchanger for a low capital cost closed cycle gas turbine.
- ArnoVW 4y ago
  1) makes the same mistake as the author. Yes, after 600 years you can hold it in your hand for a brief moment without dying. You have to swallow, or be in contact 24/7. But if you live in an area with contaminated air or water, you're going to swallow, and on a daily basis. The difficulty of nuclear storage is not guarding highly radioactive stuff the first 100 years. It's the medium and low radioactive stuff that you need to keep out of the water and air the next 10,000. Also, even if you don't drop dead straight away, if your life is shortened by 10 years, that sort of sucks too. Of course, that means you need to concern yourself with the people will live then. And since we are already having great difficulty keeping our place in the universe habitable for our children...
  - chasil 4y ago
    Contrast this with the dangers to humanity inherent in other forms of power generation. Hydropower has, thus far, proven far more dangerous. The collapse of the Banqiao dam in China led to between 26,000 to 240,000 estimated fatalities that impacted 30 cities. https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure Coal, of course, exceeds this by orders of magnitude.
    - pydry 4y ago
      Wind, solar, batteries and pumped storage have yet to kill 240,000 people and are cheaper than nuclear power. It's not 1980 any more.
      - acidburnNSA 4y ago
        Nuclear has yet to kill 240,000 people as well. Fossil and biofuel normal-operation particulates kill a high-ball long-term Chernobyl worth of people every 8 hours.
        twaw 4y ago
        Emm, these people are killed by cancer, every year. Unless we will find cure for cancer very soon, Chornobyl kills dozens of thousands per year right now.
deleted 4y ago
[deleted]
whycome 4y ago
the spent fuel still produces a lot of heat. have there been examples of somehow utilizing the waste while it degrades?
- LeoPanthera 4y ago
  That is called a "Radioisotope thermoelectric generator" but it's not the magic bullet that it appears to be. Depending on the isotope, you either get a very tiny amount of power (far less than you'd get from a solar array), or a very short half life. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
  - whycome 4y ago
    I mean maybe not even powergen. Store it in the arctic where the population is low, people are unlikely to stumble across it, and then use the latent heat to heat homes or greenhouses or something. Also, I don't think seismically active and things like flooding/hurricanes aren't a thing. If the containers can keep their integrity, why not? If if not enough to fully heat homes/water/whatever, it would at least reduce the need for other sources. Of course this all depends on if the stuff can be stored safely -- and I think that's mostly solved?
deleted 4y ago
[deleted]
Schroedingersat 4y ago
Sleight of hand and lies as usual. Breeder reactors do not actually exist and never have. Hitting some fertile material with fast or heavy water moderated neutrons is the easy part. Reprocessing reactor grade plutonium is the hard part and every program that has attempted it on a commercial scale has failed spectacularly. The french reprocessing facilities for ex weapons MOX are filthy, release more radiation than TMI and Fukushima combined in normal operation, and are horrifically expensive, and the others are all kept secret. The BN800 is closest as it's running ~100% MOX right now (with no indication as to the source or whether it is using the breeding blanket), but noone even has any plans to attempt to reprocess spent plutonium based fuels, so at best it just doubles the amount of energy, doubles the amount of short lived extremely high level waste, and leaves you with a slightly higher level of long lived transuranics. The danger of the long lived waste isn't handling it, it's having it enter the ground water and ecosystem where it will build up in the food chain forever.
- moloch-hai 4y ago
  Also, ingestion is neither the most dangerous or most likely route to eventually-fatal exposure: inhalation of radioactive dust is the hazard. It might take years to deliver lung cancer, on schedule, but it is a bad way to go.
- Manuel_D 4y ago
  > The french reprocessing facilities for ex weapons MOX are filthy, release more radiation than TMI and Fukushima combined in normal operation, and are horrifically expensive, and the others are all kept secret. The only people making these claims are Greenpeace: https://en.m.wikipedia.org/wiki/La_Hague_site https://en.m.wikipedia.org/wiki/La_Hague_site In reality, a single transatlantic flight will expose you to more radiation than spending a year at the reprocessing site. Greenpeace had zero credibility on nuclear power. They think a million people died from Chernobyl. This is nothing more than propaganda. > The danger of the long lived waste isn't handling it, it's having it enter the ground water and ecosystem where it will build up in the food chain forever. You realize that naturally occurring uranium already contaminates many regions water supplies? But it's not the end of the world, it can be treated and filtered out: https://www.kqed.org/stateofhealth/120396/uranium-contaminates-water-california-central-valley https://www.kqed.org/stateofhealth/120396/uranium-contaminat...
yawnxyz 4y ago
> Keep the material in dry cask storage until the photon emitters have mostly decayed away, at most 600 years. If the US were to generate all its electricity from nuclear, a 600 year decay time means she would have to devote at most 21 square miles — about the size of Manhattan — to dry cask storage. This is based on the Histore system, Figure 5, which needs one acre to store 580 tons of used fuel. Does anyone actually believe that our energy needs will never grow over time, and that growth isn't exponential?
- paulryanrogers 4y ago
  > Does anyone actually believe that our energy needs will never grow over time, and that growth isn't exponential? IME we minimize the negative when considering costs of things we strongly desire. When considering our ability to pay costs in the future we are similarly (overly) optimistic.
- i_am_proteus 4y ago
  Yes. https://www.eia.gov/energyexplained/us-energy-facts/ https://www.eia.gov/energyexplained/us-energy-facts/
twhitmore 4y ago
My understanding is that radioactive waste volumes & activity differ based on reactor type. Light-water reactors (PWR/ BWR) only burn 3% of the fuel energy hence leaving large energies as mid- and high-level radioactive waste. Heavy-water reactors such as CANDU can achieve greater burn-up, can avoid enrichment, and even reportedly burn waste from PWRs as fuel. There are downsides but to my mind they seem small. https://en.m.wikipedia.org/wiki/CANDU_reactor#Fuel_cycle https://en.m.wikipedia.org/wiki/CANDU_reactor#Fuel_cycle

58 points by jseliger 4y ago

Two points really stand out here. 1.) Nuclear waste can be handled by hand after 600 years. 2.) Coal plant: 3-6 Million tons of toxic ash in its operating life, not to mention 110 million tons of CO vs 1000 tons of nuclear waste.

sneakerblack 4y ago
Something that the article didn't mention is that coal plants also produce radiation, and because of the lack of protection against it, the average dose of yearly radiation you get living near a coal plant is actually higher than living near a nuclear plant. That said, the repercussions of a major disaster are a lot lower with a coal plant than with a nuclear plant. And, as always, relevant XKCD: https://xkcd.com/radiation/ https://xkcd.com/radiation/
- fsh 4y ago
  This factoid about coal power plants is often repeated, but I have my doubts about the accuracy. It seems to be based on a 44 year old paper [1] which comes to the conclusion that the radiation dose you get from living near a coal plant is on the same order of magnitude as the one from living near a BWR or PWR (Table 5 in the reference). However, emissions regulations for power plants (fossil or nuclear) are surely very different in 2022 than they were in 1978. [1] https://www.science.org/doi/10.1126/science.202.4372.1045 https://www.science.org/doi/10.1126/science.202.4372.1045
rapjr9 4y ago
Two things that are glossed over are "Others can be processed into excellent nuclear fuel, although currently this is not quite economic, in part because the fission product decay makes handling the used fuel so difficult." So we don't know how to do this yet, and processing spent fuel rods also produces a lot of toxic and radioactive byproducts that are also difficult to handle, take a look at this Superfund site: https://nmisite.org/site-history/ https://nmisite.org/site-history/ The other thing the article does not even mention is meltdowns of operating plants and attacks on or natural disasters affecting dry cask storage and reprocessing plants. Sure, you have to eat or breath the material for it to be dangerous after 600 years, but if a plant melts down or an idiot blows up the spent fuel then it gets into water, food, soil and the air and everyone ingests it, for a very long time thereafter, BEFORE the 600 years is up. Also, keeping something safe for 600 years is something nobody has ever done. Most societies don't even last 600 years. Look at what a mess we made of it just 50 years ago: https://www.latimes.com/environment/story/2020-07-01/us-says-nuclear-waste-safe-marshall-islands-runit-dome https://www.latimes.com/environment/story/2020-07-01/us-says... And here is a list of how well we've handled nuclear materials so far: "11 Nuclear meltdowns and Disasters" https://www.cnbc.com/2011/03/16/11-Nuclear-Meltdowns-and-Disasters.html https://www.cnbc.com/2011/03/16/11-Nuclear-Meltdowns-and-Dis... The Zaporizhzhia nuclear plant in Ukraine is currently being shelled. Again. So it seems world peace is a prerequisite, I'd like to see the plan for that. After we've achieved world peace then the 600 year containment experiments can start and we can figure out how to get our engineering to 99.99999% reliability. Smaller, less dangerous, and inherently safer reactor designs are being tried, maybe one of those will work well enough to be able to ramp up nuclear power, but the technology in current use is not good enough.
- PaulHoule 4y ago
  Aqueous reprocessing of nuclear fuel is a technology that's been mastered by many nations. Fabricating quality MOX that be fed back into reactors is something that France and Russia have succeeded at and the US and UK have failed at. That said, there might be some other way to make MOX, or some other fuel formulation based on molten salts, metal fuel, nitrides, carbides, etc. As for economics a big problem is that the LWR works at low temperatures and requires a huge steam turbine and huge heat exchangers. This is apart from the problem that large LWR construction projects frequently go over schedule and budget by a large margin. There is some hope that a smaller reactor like China's ACP-100 can find some simplification at small scale that makes up for the diseconomies of small scale and avoids the project management problems but it will take some kind of water-free reactor that operates at higher temperatures for nuclear to be competitive with natural gas.
  - deleted 4y ago
    [deleted]
  - credit_guy 4y ago
    > Fabricating quality MOX that be fed back into reactors MOX can be fed back only once. After that too much Pu-240 accumulates, and that's a non-fissile element that absorbs a lot of neutrons, so it's a neutron poison (see [1]). Pu-240 can't be separated from Pu-239, except using the same methods to separate U-235 from U-238 (but more difficult, since the relative atomic mass difference is much smaller). If you get into the business of isotope separation, you might as well enrich Uranium. [1] https://en.wikipedia.org/wiki/MOX_fuel#Spent_MOX_fuel https://en.wikipedia.org/wiki/MOX_fuel#Spent_MOX_fuel
    - PaulHoule 4y ago
      With a fast reactor you can keep the cycle going. Russia is recycling MOX with the BN-800 fast reactor. The U.S. did it too with the FFTF but the FFTF dumped the heat to the air without trying to produce power. Oddly, this makes the FFTF look more like a future fast reactor because the heat exchanger for the FFTF looks more like the heat exchanger for a low capital cost closed cycle gas turbine.
ArnoVW 4y ago
1) makes the same mistake as the author. Yes, after 600 years you can hold it in your hand for a brief moment without dying. You have to swallow, or be in contact 24/7. But if you live in an area with contaminated air or water, you're going to swallow, and on a daily basis. The difficulty of nuclear storage is not guarding highly radioactive stuff the first 100 years. It's the medium and low radioactive stuff that you need to keep out of the water and air the next 10,000. Also, even if you don't drop dead straight away, if your life is shortened by 10 years, that sort of sucks too. Of course, that means you need to concern yourself with the people will live then. And since we are already having great difficulty keeping our place in the universe habitable for our children...
- chasil 4y ago
  Contrast this with the dangers to humanity inherent in other forms of power generation. Hydropower has, thus far, proven far more dangerous. The collapse of the Banqiao dam in China led to between 26,000 to 240,000 estimated fatalities that impacted 30 cities. https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure Coal, of course, exceeds this by orders of magnitude.
  - pydry 4y ago
    Wind, solar, batteries and pumped storage have yet to kill 240,000 people and are cheaper than nuclear power. It's not 1980 any more.
    - acidburnNSA 4y ago
      Nuclear has yet to kill 240,000 people as well. Fossil and biofuel normal-operation particulates kill a high-ball long-term Chernobyl worth of people every 8 hours.
      - twaw 4y ago
        Emm, these people are killed by cancer, every year. Unless we will find cure for cancer very soon, Chornobyl kills dozens of thousands per year right now.

deleted 4y ago

[deleted]

whycome 4y ago

the spent fuel still produces a lot of heat. have there been examples of somehow utilizing the waste while it degrades?

LeoPanthera 4y ago
That is called a "Radioisotope thermoelectric generator" but it's not the magic bullet that it appears to be. Depending on the isotope, you either get a very tiny amount of power (far less than you'd get from a solar array), or a very short half life. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
- whycome 4y ago
  I mean maybe not even powergen. Store it in the arctic where the population is low, people are unlikely to stumble across it, and then use the latent heat to heat homes or greenhouses or something. Also, I don't think seismically active and things like flooding/hurricanes aren't a thing. If the containers can keep their integrity, why not? If if not enough to fully heat homes/water/whatever, it would at least reduce the need for other sources. Of course this all depends on if the stuff can be stored safely -- and I think that's mostly solved?

deleted 4y ago

[deleted]

Schroedingersat 4y ago

Sleight of hand and lies as usual. Breeder reactors do not actually exist and never have. Hitting some fertile material with fast or heavy water moderated neutrons is the easy part. Reprocessing reactor grade plutonium is the hard part and every program that has attempted it on a commercial scale has failed spectacularly. The french reprocessing facilities for ex weapons MOX are filthy, release more radiation than TMI and Fukushima combined in normal operation, and are horrifically expensive, and the others are all kept secret. The BN800 is closest as it's running ~100% MOX right now (with no indication as to the source or whether it is using the breeding blanket), but noone even has any plans to attempt to reprocess spent plutonium based fuels, so at best it just doubles the amount of energy, doubles the amount of short lived extremely high level waste, and leaves you with a slightly higher level of long lived transuranics. The danger of the long lived waste isn't handling it, it's having it enter the ground water and ecosystem where it will build up in the food chain forever.

moloch-hai 4y ago
Also, ingestion is neither the most dangerous or most likely route to eventually-fatal exposure: inhalation of radioactive dust is the hazard. It might take years to deliver lung cancer, on schedule, but it is a bad way to go.
Manuel_D 4y ago
> The french reprocessing facilities for ex weapons MOX are filthy, release more radiation than TMI and Fukushima combined in normal operation, and are horrifically expensive, and the others are all kept secret. The only people making these claims are Greenpeace: https://en.m.wikipedia.org/wiki/La_Hague_site https://en.m.wikipedia.org/wiki/La_Hague_site In reality, a single transatlantic flight will expose you to more radiation than spending a year at the reprocessing site. Greenpeace had zero credibility on nuclear power. They think a million people died from Chernobyl. This is nothing more than propaganda. > The danger of the long lived waste isn't handling it, it's having it enter the ground water and ecosystem where it will build up in the food chain forever. You realize that naturally occurring uranium already contaminates many regions water supplies? But it's not the end of the world, it can be treated and filtered out: https://www.kqed.org/stateofhealth/120396/uranium-contaminates-water-california-central-valley https://www.kqed.org/stateofhealth/120396/uranium-contaminat...

yawnxyz 4y ago

> Keep the material in dry cask storage until the photon emitters have mostly decayed away, at most 600 years. If the US were to generate all its electricity from nuclear, a 600 year decay time means she would have to devote at most 21 square miles — about the size of Manhattan — to dry cask storage. This is based on the Histore system, Figure 5, which needs one acre to store 580 tons of used fuel. Does anyone actually believe that our energy needs will never grow over time, and that growth isn't exponential?

paulryanrogers 4y ago
> Does anyone actually believe that our energy needs will never grow over time, and that growth isn't exponential? IME we minimize the negative when considering costs of things we strongly desire. When considering our ability to pay costs in the future we are similarly (overly) optimistic.
i_am_proteus 4y ago
Yes. https://www.eia.gov/energyexplained/us-energy-facts/ https://www.eia.gov/energyexplained/us-energy-facts/

twhitmore 4y ago

My understanding is that radioactive waste volumes & activity differ based on reactor type. Light-water reactors (PWR/ BWR) only burn 3% of the fuel energy hence leaving large energies as mid- and high-level radioactive waste. Heavy-water reactors such as CANDU can achieve greater burn-up, can avoid enrichment, and even reportedly burn waste from PWRs as fuel. There are downsides but to my mind they seem small. https://en.m.wikipedia.org/wiki/CANDU_reactor#Fuel_cycle https://en.m.wikipedia.org/wiki/CANDU_reactor#Fuel_cycle