9 ms·

Thorium Instead Of Uranium: Solution To Our Energy Woes?

76 points by johndcook 16y ago

johndcook 16y ago
The post doesn't give a definite answer to the question in the title, but it is interesting.
- ScotterC 16y ago
  It could be a plausible solution to our electricity woes to a degree. Mainly in baseload electricity supply which is about 60% of the U.S. grid. Small liquid flouride thorium reactors (LFTRs) can fit on a flatbed truck and mass manufactured. The idea is that we can connect these to existing coal plant secondary systems around the country and replace the coal boilers. Thorium is extremely abundant. We have 3000 tons of it sitting in nevada gathering dust because we have nothing better to do with it. Also, you can get an incredible amount of energy and little waste out of a liquid thorium reactor. See http://energyfromthorium.com/ http://energyfromthorium.com/. That's Kirk Sorensen's blog. A NASA engineer who's really led the movement on LFTRs and got featured in Wired for it.
  - pjscott 16y ago
    If we can get the cost per megawatt of capacity low enough, liquid fluoride thorium reactors could even be used for peak power. They can scale their power output up and down pretty rapidly, since they would use Brayton-cycle gas turbines for power conversion, and it's possible to continuously (or very frequently) remove xenon-135, which is a neutron poison and has traditionally made it harder to adjust the power output of nuclear reactors.
    - ScotterC 16y ago
      Isn't it wonderful how we've barely scratched the surface on what potential fission has?
mattstat 16y ago
Thorium is 4 times more abundant in the Earth’s crust than uranium. It occurs in only one isotope, thorium-232. There is therefore no isotope separation, and 100% of the mined thorium is useful in a power reactor. Very little of the mined uranium is useful. You can’t make a bomb out of thorium.
GiraffeNecktie 16y ago
The short answer is that there are many entrenched interests who are not keen on the idea: Uranium mines, nuclear industry, weapons manufacturers, not to mention the oil, gas and coal lobbies, even the alternative energy suppliers like solar. Thorium would rain on all their parades.
- ScotterC 16y ago
  Exactly. Mainly, the current nuclear power industry, i.e. Areva, Westinghouse and GE make all their money on the fabrication fo fuel rod assemblies. They tried to make thorium fuel rods work in Indian Point Unit 1, but the layout of the rod bundles was tough to optimize to allow fertile material to become fissile and cycle correctly to be efficient at heating up the primary coolant. Add this to all the regulatory hurdles and the big three nuke companies see no reason to pursue such a financial risk.
- Retric 16y ago
  The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap. The fuel costs for a modern reactor are a small fraction of total cost. Also, fosil fuels a not going to be replaced with wind, solar, fission or fusion any time soon because they are not really portable for anything smaller than a boat.
  - sdurkin 16y ago
    You're both right. "The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap." This answers why the market won't develop the technology on its own. But the government could still sponsor research as they did with uranium fission. "The short answer is that there are many entrenched interests who are not keen on the idea..." And this answers why the government would never fund it.
    - wtallis 16y ago
      As soon as the market has to bear the cost of long-term storage of waste, they'll be interested in thorium.
ngvrnd 16y ago
I've read somewhere that one problem with Thorium is it can easily be converted to a fissionable isotope (of Uranium?) which can be used to build bombs. So there's that.
- randallsquared 16y ago
  One of the anti-proliferation points is that U233 (which is the isotope you're thinking of) is mixed with U232, which decays to products with high gamma output, meaning that it's more dangerous to work with than the more typical fissionable materials, and much easier to detect. For a state this probably wouldn't be a significant barrier, but it's a fair point with respect to terrorist bombs. Of course, we haven't seen any of those, which implies that there's some non-obvious factor at work, here.
  - CWuestefeld 16y ago
    From the OP: You will hear that we can’t make bombs out of U-233 because it is a virulent gamma-ray emitter. This is not true, and I find it curious that it is used as a reason. U-233 has a 158,000-year half-life. What they are referring to is the protactinium-233 contaminant, which has a 27-day half-life, beta-decaying into U-233 with gamma-ray involvement. Chemically scrub the protactinium, of course, or just wait a year and it will be gone.
    - pjscott 16y ago
      No, that's wrong. The claim is that the bred U-233 will be contaminated with U-232, which is very hard to get rid of, and has the hard gamma emitter Thallium-208 in its decay chain.
      - tkeller 16y ago
        Where would the U-232 contamination come from, if it's bred U-233? Does thorium also just sometimes decay into the lighter isotope?
magamiako 16y ago
If you need lots of thorium you can usually find a ton of it Winterspring or the Burning Steppes!
- ScotterC 16y ago
  You can find it pretty much anywhere actually. It's a by-product of many mining processes and India has literal beaches of it.
  - AndrewHampton 16y ago
    I believe magamiako is referring to areas in World of Warcraft where thorium can be found.
    - pjscott 16y ago
      Incidentally, comments like that are why it's so irritating to try to have discussions of thorium on Reddit. Of the people who post in those threads, a significant fraction are just there to make WoW references.
      - hugh3 16y ago
        I have the same problem with discussions of Uranus.
    - ScotterC 16y ago
      Haha. That went completely over my head. Woosh!
grandinj 16y ago
This is a classic case of a solution to a problem that does not exist. Firstly, Uranium is practically an insignificant cost of a nuclear power station. The price would have to go up by a factor of a 100 before it made a difference. Secondly, the supplies of uranium are currently limited because the demand is limited. The moment the price shifts up by even a little, supply will grow because several other mining locations will become profitable.
- edfrtghjkjh 16y ago
  True for the US with a big supply of uranium in a (relatively) friendly country to the north. Different for say India that has lots of Thorium, no Uranium and doesn't want to go begging to Russia or spend hard currency in Canada.
- Retric 16y ago
  We have already mined something like 100 years worth of Uranium that is just waiting around to be used in power plants. Or, if the US moved to breeder reactors we could go for something like 1000 years without mining any new uranium.
  - olegkikin 16y ago
    Your 100 and 1000 year assumptions are just silly. You assume energy demands will remain constant, while they are exponential. Just think what will happen if electric cars become popular. We will need a lot of electricity.
    - Retric 16y ago
      Resource usage tends to follow a http://en.wikipedia.org/wiki/Logistic_function http://en.wikipedia.org/wiki/Logistic_function not pure exponential growth. Picking a good limit is hard but assuming energy use per person is stays around 5x our current value and US population is limited to 1 billion people 1000 years is an extremely conservative estimate. Conceder: Between 1980 and 2006, the worldwide annual growth rate was 2%. (http://en.wikipedia.org/wiki/World_energy_resources_and_consumption http://en.wikipedia.org/wiki/World_energy_resources_and_cons...) If you assume world energy usage will grow 2% per year for the next thousand years you end up with 400,000 times current energy usage however, the sun only supplies the earth with ~10,000 times our current energy use so we would fry the planet with waste heat far before that level. (Think global warming to 800 degrees Fahrenheit.) PS: In 2009, world energy consumption decreased for the first time in 30 years (-1.1%) or 130Mtoe, as a result of the financial and economic crisis (GDP drop by 0.6% in 2009) so growth is not necessarily even guaranteed.
DanielBMarkham 16y ago
I'm a big fan of Thorium, but I'm also a big fan of nuclear in general. It just makes sense. In fact, this is a lot like the issue of not building any oil refineries in the United States since the 1970s. While I'm sure there are good reasons for our lack of needed nuke plants, at the end of the day it looks like the system has let us all down. I hate to sound like old cranky guy again, but frack, if you really wanted to get off oil you could do the math for how many nuke plants you'd need -- it'd be a lot! But it wouldn't be impossible, and we've known all of this for decades. It's just very frustrating. Things like the thorium ideas just make things worse because we can't even solve our problems using the old technology, much less the new stuff. It's almost like rubbing salt in the wound to see such potential and realize how improbable it will be to see the light of day (in a massive production sense). I find the state of our energy policy completely incredible, but the tech continues to look better with each passing year. Sigh.
- henrikschroder 16y ago
  Nuclear power plants can't replace oil- or coal-powered plants, because nuclear plants can't adjust output over the day to fit actual usage. Nuclear power plants are great for providing the baseline power production, but you need something adjustable to handle the morning and evening peaks, like oil or coal or wind or hydro or really big batteries. So no, you can't do the math for how many nuclear plants you would need to get off oil.
  - cameldrv 16y ago
    Sure they can. Hybrids that charge at night, that get cheaper rates to charge when the utility sends a signal, pumped storage, only running hydroelectric during the day, running aluminum smelters at night, thermal storage, or worst case, just not using the extra electricity. There is stuff to build, but we're not going to build all of those nuke plants overnight either.
  - ColinDabritz 16y ago
    Can we not solve this problem by storing energy in the longer term? It's true some 'burst' capacity is important, but can you not get a lot closer to 'average load' than the baseline by using the energy? Pumping water into a reservoir at night, and getting the power back with a small hydro plant during the day comes to mind. We smooth out an even worse problem with wind and solar, which is spiky AND out of sync with demand sometimes. I believe flywheels are used to store energy in the short term sometimes. You did mention 'really big batteries', implying that we would need too many, but we aren't limited to chemical forms of energy storage. I think this is a solved problem, or at least a fairly solvable problem, and nuke plants can provide not only the 'baseline' but close to the bulk average needs for power. We can decouple the power generation and the need for "something adjustable" and benefit.
whyenot 16y ago
I'm all for thorium and nuclear energy, BUT only if we in the US stop with the NIMBY-ing and find a permanent storage location for nuclear waste.
- warfangle 16y ago
  No need for a 'permanent storage solution' for thorium waste. What little waste there is decays to safe levels in less half a century.
muhfuhkuh 16y ago
I thought all of the arguments against nuclear were overwhelmingly about NIMBY (not in my backyard). People just look at Three Mile Island and Chernobyl and think "hell no." Maybe after the BP spill, we'll think a little more about nuclear.
ericd 16y ago
Wouldn't getting over our fear of reprocessing Uranium make this a non-issue? That seems the simplest and most straightforward path... Just have to figure out a way to lock down the resulting plutonium.

76 points by johndcook 16y ago

johndcook 16y ago

The post doesn't give a definite answer to the question in the title, but it is interesting.

ScotterC 16y ago
It could be a plausible solution to our electricity woes to a degree. Mainly in baseload electricity supply which is about 60% of the U.S. grid. Small liquid flouride thorium reactors (LFTRs) can fit on a flatbed truck and mass manufactured. The idea is that we can connect these to existing coal plant secondary systems around the country and replace the coal boilers. Thorium is extremely abundant. We have 3000 tons of it sitting in nevada gathering dust because we have nothing better to do with it. Also, you can get an incredible amount of energy and little waste out of a liquid thorium reactor. See http://energyfromthorium.com/ http://energyfromthorium.com/. That's Kirk Sorensen's blog. A NASA engineer who's really led the movement on LFTRs and got featured in Wired for it.
- pjscott 16y ago
  If we can get the cost per megawatt of capacity low enough, liquid fluoride thorium reactors could even be used for peak power. They can scale their power output up and down pretty rapidly, since they would use Brayton-cycle gas turbines for power conversion, and it's possible to continuously (or very frequently) remove xenon-135, which is a neutron poison and has traditionally made it harder to adjust the power output of nuclear reactors.
  - ScotterC 16y ago
    Isn't it wonderful how we've barely scratched the surface on what potential fission has?

mattstat 16y ago

Thorium is 4 times more abundant in the Earth’s crust than uranium. It occurs in only one isotope, thorium-232. There is therefore no isotope separation, and 100% of the mined thorium is useful in a power reactor. Very little of the mined uranium is useful. You can’t make a bomb out of thorium.

GiraffeNecktie 16y ago

The short answer is that there are many entrenched interests who are not keen on the idea: Uranium mines, nuclear industry, weapons manufacturers, not to mention the oil, gas and coal lobbies, even the alternative energy suppliers like solar. Thorium would rain on all their parades.

ScotterC 16y ago
Exactly. Mainly, the current nuclear power industry, i.e. Areva, Westinghouse and GE make all their money on the fabrication fo fuel rod assemblies. They tried to make thorium fuel rods work in Indian Point Unit 1, but the layout of the rod bundles was tough to optimize to allow fertile material to become fissile and cycle correctly to be efficient at heating up the primary coolant. Add this to all the regulatory hurdles and the big three nuke companies see no reason to pursue such a financial risk.
Retric 16y ago
The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap. The fuel costs for a modern reactor are a small fraction of total cost. Also, fosil fuels a not going to be replaced with wind, solar, fission or fusion any time soon because they are not really portable for anything smaller than a boat.
- sdurkin 16y ago
  You're both right. "The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap." This answers why the market won't develop the technology on its own. But the government could still sponsor research as they did with uranium fission. "The short answer is that there are many entrenched interests who are not keen on the idea..." And this answers why the government would never fund it.
  - wtallis 16y ago
    As soon as the market has to bear the cost of long-term storage of waste, they'll be interested in thorium.

ngvrnd 16y ago

I've read somewhere that one problem with Thorium is it can easily be converted to a fissionable isotope (of Uranium?) which can be used to build bombs. So there's that.

randallsquared 16y ago
One of the anti-proliferation points is that U233 (which is the isotope you're thinking of) is mixed with U232, which decays to products with high gamma output, meaning that it's more dangerous to work with than the more typical fissionable materials, and much easier to detect. For a state this probably wouldn't be a significant barrier, but it's a fair point with respect to terrorist bombs. Of course, we haven't seen any of those, which implies that there's some non-obvious factor at work, here.
- CWuestefeld 16y ago
  From the OP: You will hear that we can’t make bombs out of U-233 because it is a virulent gamma-ray emitter. This is not true, and I find it curious that it is used as a reason. U-233 has a 158,000-year half-life. What they are referring to is the protactinium-233 contaminant, which has a 27-day half-life, beta-decaying into U-233 with gamma-ray involvement. Chemically scrub the protactinium, of course, or just wait a year and it will be gone.
  - pjscott 16y ago
    No, that's wrong. The claim is that the bred U-233 will be contaminated with U-232, which is very hard to get rid of, and has the hard gamma emitter Thallium-208 in its decay chain.
    - tkeller 16y ago
      Where would the U-232 contamination come from, if it's bred U-233? Does thorium also just sometimes decay into the lighter isotope?

magamiako 16y ago

If you need lots of thorium you can usually find a ton of it Winterspring or the Burning Steppes!

ScotterC 16y ago
You can find it pretty much anywhere actually. It's a by-product of many mining processes and India has literal beaches of it.
- AndrewHampton 16y ago
  I believe magamiako is referring to areas in World of Warcraft where thorium can be found.
  - pjscott 16y ago
    Incidentally, comments like that are why it's so irritating to try to have discussions of thorium on Reddit. Of the people who post in those threads, a significant fraction are just there to make WoW references.
    - hugh3 16y ago
      I have the same problem with discussions of Uranus.
  - ScotterC 16y ago
    Haha. That went completely over my head. Woosh!

grandinj 16y ago

This is a classic case of a solution to a problem that does not exist. Firstly, Uranium is practically an insignificant cost of a nuclear power station. The price would have to go up by a factor of a 100 before it made a difference. Secondly, the supplies of uranium are currently limited because the demand is limited. The moment the price shifts up by even a little, supply will grow because several other mining locations will become profitable.

edfrtghjkjh 16y ago
True for the US with a big supply of uranium in a (relatively) friendly country to the north. Different for say India that has lots of Thorium, no Uranium and doesn't want to go begging to Russia or spend hard currency in Canada.
Retric 16y ago
We have already mined something like 100 years worth of Uranium that is just waiting around to be used in power plants. Or, if the US moved to breeder reactors we could go for something like 1000 years without mining any new uranium.
- olegkikin 16y ago
  Your 100 and 1000 year assumptions are just silly. You assume energy demands will remain constant, while they are exponential. Just think what will happen if electric cars become popular. We will need a lot of electricity.
  - Retric 16y ago
    Resource usage tends to follow a http://en.wikipedia.org/wiki/Logistic_function http://en.wikipedia.org/wiki/Logistic_function not pure exponential growth. Picking a good limit is hard but assuming energy use per person is stays around 5x our current value and US population is limited to 1 billion people 1000 years is an extremely conservative estimate. Conceder: Between 1980 and 2006, the worldwide annual growth rate was 2%. (http://en.wikipedia.org/wiki/World_energy_resources_and_consumption http://en.wikipedia.org/wiki/World_energy_resources_and_cons...) If you assume world energy usage will grow 2% per year for the next thousand years you end up with 400,000 times current energy usage however, the sun only supplies the earth with ~10,000 times our current energy use so we would fry the planet with waste heat far before that level. (Think global warming to 800 degrees Fahrenheit.) PS: In 2009, world energy consumption decreased for the first time in 30 years (-1.1%) or 130Mtoe, as a result of the financial and economic crisis (GDP drop by 0.6% in 2009) so growth is not necessarily even guaranteed.

DanielBMarkham 16y ago

I'm a big fan of Thorium, but I'm also a big fan of nuclear in general. It just makes sense. In fact, this is a lot like the issue of not building any oil refineries in the United States since the 1970s. While I'm sure there are good reasons for our lack of needed nuke plants, at the end of the day it looks like the system has let us all down. I hate to sound like old cranky guy again, but frack, if you really wanted to get off oil you could do the math for how many nuke plants you'd need -- it'd be a lot! But it wouldn't be impossible, and we've known all of this for decades. It's just very frustrating. Things like the thorium ideas just make things worse because we can't even solve our problems using the old technology, much less the new stuff. It's almost like rubbing salt in the wound to see such potential and realize how improbable it will be to see the light of day (in a massive production sense). I find the state of our energy policy completely incredible, but the tech continues to look better with each passing year. Sigh.

henrikschroder 16y ago
Nuclear power plants can't replace oil- or coal-powered plants, because nuclear plants can't adjust output over the day to fit actual usage. Nuclear power plants are great for providing the baseline power production, but you need something adjustable to handle the morning and evening peaks, like oil or coal or wind or hydro or really big batteries. So no, you can't do the math for how many nuclear plants you would need to get off oil.
- cameldrv 16y ago
  Sure they can. Hybrids that charge at night, that get cheaper rates to charge when the utility sends a signal, pumped storage, only running hydroelectric during the day, running aluminum smelters at night, thermal storage, or worst case, just not using the extra electricity. There is stuff to build, but we're not going to build all of those nuke plants overnight either.
- ColinDabritz 16y ago
  Can we not solve this problem by storing energy in the longer term? It's true some 'burst' capacity is important, but can you not get a lot closer to 'average load' than the baseline by using the energy? Pumping water into a reservoir at night, and getting the power back with a small hydro plant during the day comes to mind. We smooth out an even worse problem with wind and solar, which is spiky AND out of sync with demand sometimes. I believe flywheels are used to store energy in the short term sometimes. You did mention 'really big batteries', implying that we would need too many, but we aren't limited to chemical forms of energy storage. I think this is a solved problem, or at least a fairly solvable problem, and nuke plants can provide not only the 'baseline' but close to the bulk average needs for power. We can decouple the power generation and the need for "something adjustable" and benefit.

whyenot 16y ago

I'm all for thorium and nuclear energy, BUT only if we in the US stop with the NIMBY-ing and find a permanent storage location for nuclear waste.

warfangle 16y ago
No need for a 'permanent storage solution' for thorium waste. What little waste there is decays to safe levels in less half a century.

muhfuhkuh 16y ago

I thought all of the arguments against nuclear were overwhelmingly about NIMBY (not in my backyard). People just look at Three Mile Island and Chernobyl and think "hell no." Maybe after the BP spill, we'll think a little more about nuclear.

ericd 16y ago

Wouldn't getting over our fear of reprocessing Uranium make this a non-issue? That seems the simplest and most straightforward path... Just have to figure out a way to lock down the resulting plutonium.