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They are also running 4th generation thorium molten salt reactors prototypes and thinking of having a commercial viable design in 2030. From what I gathered the

They are also running 4th generation thorium molten salt reactors prototypes and thinking of having a commercial viable design in 2030. From what I gathered the waste is not that suitable for nuclear weapon usage. So those Reactors could be exported to SCO/BRI/global south countries. https://www.nature.com/articles/d41586-021-02459-w https://www.nature.com/articles/d41586-021-02459-w

ortusdux 5y ago
The problem with molten salt based reactors is that the high temperature radioactive molten salts destroy their containment vessels. I've yet to see a system design where the salt facing components are expected to last more that 7-10 years, which really hurts profitability.
- sudosysgen 5y ago
  Yes, the reactor cores would have to be replaced every 12-15 years. But if the reactors are mass produced and designed to swap out the cores, it doesn't have to be too expensive.
  - mcguire 5y ago
    What happens to the used cores?
    - sudosysgen 5y ago
      They have to be disposed of. That creates waste. This is the same as with any other power generation method that exceeds it's lifespan. 15 years is not that different from 20 years for a wind turbine or 30 years for a solar panel.
      - spfzero 5y ago
        Solar panels are lasting about 10-15 years in practice. About half of what was expected.
        jhgb 5y ago
        I call BS on that. This was the performance of ancient modules (early 1980s) after 25 years of operation: https://energiforskmedia.blob.core.windows.net/media/19320/performance-of-old-pv-modules-measurement-of-25-years-old-crystalline-silicone-modules-elforskrapport-2006-71.pdf https://energiforskmedia.blob.core.windows.net/media/19320/p... And this was for modules manufactured in a period with 5-10 year warranties for the product. Today you get 25 year warranties. So you're basically claiming that QA massively worsened in the meantime.
  - bipson 5y ago
    Still not "sustainable". And not really cheap either.
    - sudosysgen 5y ago
      It is actually quite sustainable. The reactor core is not a large cost for a GW over 15 years. The US navy swaps out reactor cores for 100-200 million dollars, and those are in submarines and ships. There is basically no maintenance outside of those. For comparison, a GW of wind capacity is 1.6 billion every 20 years. For solar panels for 1GW of average generation you'll be paying 10 billion dollars or so every 25-30 years.
      - avianlyric 5y ago
        I think GP meant environmentally sustainable, rather than fiscally sustainable, you need to do something with the old reactor cores.
        sudosysgen 5y ago
        The reactor core will probably be drained of molten salts and then treated as low level radioactive waste. Yes it is waste, but I don't see anyone making the argument with wind turbines or solar panels, which will create more waste in total.
        robviren 5y ago
        What does a coal plant do with the emitted radiation, CO2, coal ash, and other waste products? Current spent fuel rods from nuclear reactors sit in concrete casks located on site usually. At least I don't need to breath spent nuclear fuel or have to deal with it's CO2. Not saying we should do nothing about it, but at least the impact to my life today is substantially less.
        varajelle 5y ago
        > you need to do something with the old reactor cores. You burry it deep in a geologically stable ground [1]. Was that not counted in the price? [1] https://en.m.wikipedia.org/wiki/Deep_geological_repository https://en.m.wikipedia.org/wiki/Deep_geological_repository
  - worik 5y ago
    The core will be radioactive for hundreds of thousands of years will it not?
    - sudosysgen 5y ago
      The molten salt will be quite radioactive, yes. It is part of the radioactive waste generated by a molten salt reactor. Some types of molten salt reactors do not have this problem, but I don't think they are the most practical. The metal containing the molten salts might become somewhat radioactive too. All in all, this is still comparable in amount of waste to water cooled reactors.
    - concordDance 5y ago
      Which is nowhere near as big a deal as it sounds. The damage it will do (on average) if glassed and buried 100ft under ground is absolutely negligible at the scale we are talking about (global climate change and energy in general). Yes, there's a 1 in 10000000 chance that 2000 years from now industrial age humans recovering from the apocalypse might dig a well in exactly that location and thousands will get sick with hundreds of deaths. You could multiply that by a hundred thousand cores and it would still be negligible compared to the hundreds of millions likely to die due to climate change in the next century
      - ghostbrainalpha 5y ago
        I really liked how you framed the danger. But what about if we had a Reactor Dump storing 100's of these reactors, and then something happened to that dump, either it was hit by a meter or it was intentionally attacked in some way. Could that result in an apocalyptical type event?
        concordDance 5y ago
        No, it couldn't. It would basically be a few Chernobyls in the worst case (a 1 in 1000 year asteroid impact winning the 1 in 100 million lottery and hitting the dump) and that mostly means extra birth defects and cancer (you wouldn't want to live somewhere that gave you a 10% chance if dying due to cancer age 40, but you could still have a civilization in such a location). It doesn't end life in the impacted area. For intentional attacks there are much much easier ways of killing a lot of people.
- PaulHoule 5y ago
  There are two problems. One is corrosion/radiation damage to the reactor vessel which is probably made with something like http://www.haynesintl.com/alloys/alloy-portfolio_/Corrosion-resistant-Alloys/hastelloy-n-alloy/principle-features http://www.haynesintl.com/alloys/alloy-portfolio_/Corrosion-... The other is that most of these designs have a graphite moderator, and the graphite gets damaged in the reactor environment.
  - ortusdux 5y ago
    I would consider graphite moderators under the umbrella of salt facing components. High Ni alloys such as Hast-N have their own issues - mainly radiation induced Ni -> He embrittlement and tellurium embrittlement. That being said, they are very promising.
tehjoker 5y ago
Thorium reactors produce isotopes that can be converted into U238, which is less desirable than U235 for weapons purposes, but can be converted into a usable if annoying and expensive to manage bomb due to its high gamma production. https://www.foe.org.au/anti-nuclear/issues/nfc/power-weapons/thorium https://www.foe.org.au/anti-nuclear/issues/nfc/power-weapons...

ortusdux 5y ago

The problem with molten salt based reactors is that the high temperature radioactive molten salts destroy their containment vessels. I've yet to see a system design where the salt facing components are expected to last more that 7-10 years, which really hurts profitability.

sudosysgen 5y ago
Yes, the reactor cores would have to be replaced every 12-15 years. But if the reactors are mass produced and designed to swap out the cores, it doesn't have to be too expensive.
- mcguire 5y ago
  What happens to the used cores?
  - sudosysgen 5y ago
    They have to be disposed of. That creates waste. This is the same as with any other power generation method that exceeds it's lifespan. 15 years is not that different from 20 years for a wind turbine or 30 years for a solar panel.
    - spfzero 5y ago
      Solar panels are lasting about 10-15 years in practice. About half of what was expected.
      - jhgb 5y ago
        I call BS on that. This was the performance of ancient modules (early 1980s) after 25 years of operation: https://energiforskmedia.blob.core.windows.net/media/19320/performance-of-old-pv-modules-measurement-of-25-years-old-crystalline-silicone-modules-elforskrapport-2006-71.pdf https://energiforskmedia.blob.core.windows.net/media/19320/p... And this was for modules manufactured in a period with 5-10 year warranties for the product. Today you get 25 year warranties. So you're basically claiming that QA massively worsened in the meantime.
- bipson 5y ago
  Still not "sustainable". And not really cheap either.
  - sudosysgen 5y ago
    It is actually quite sustainable. The reactor core is not a large cost for a GW over 15 years. The US navy swaps out reactor cores for 100-200 million dollars, and those are in submarines and ships. There is basically no maintenance outside of those. For comparison, a GW of wind capacity is 1.6 billion every 20 years. For solar panels for 1GW of average generation you'll be paying 10 billion dollars or so every 25-30 years.
    - avianlyric 5y ago
      I think GP meant environmentally sustainable, rather than fiscally sustainable, you need to do something with the old reactor cores.
      - sudosysgen 5y ago
        The reactor core will probably be drained of molten salts and then treated as low level radioactive waste. Yes it is waste, but I don't see anyone making the argument with wind turbines or solar panels, which will create more waste in total.
      - robviren 5y ago
        What does a coal plant do with the emitted radiation, CO2, coal ash, and other waste products? Current spent fuel rods from nuclear reactors sit in concrete casks located on site usually. At least I don't need to breath spent nuclear fuel or have to deal with it's CO2. Not saying we should do nothing about it, but at least the impact to my life today is substantially less.
      - varajelle 5y ago
        > you need to do something with the old reactor cores. You burry it deep in a geologically stable ground [1]. Was that not counted in the price? [1] https://en.m.wikipedia.org/wiki/Deep_geological_repository https://en.m.wikipedia.org/wiki/Deep_geological_repository
- worik 5y ago
  The core will be radioactive for hundreds of thousands of years will it not?
  - sudosysgen 5y ago
    The molten salt will be quite radioactive, yes. It is part of the radioactive waste generated by a molten salt reactor. Some types of molten salt reactors do not have this problem, but I don't think they are the most practical. The metal containing the molten salts might become somewhat radioactive too. All in all, this is still comparable in amount of waste to water cooled reactors.
  - concordDance 5y ago
    Which is nowhere near as big a deal as it sounds. The damage it will do (on average) if glassed and buried 100ft under ground is absolutely negligible at the scale we are talking about (global climate change and energy in general). Yes, there's a 1 in 10000000 chance that 2000 years from now industrial age humans recovering from the apocalypse might dig a well in exactly that location and thousands will get sick with hundreds of deaths. You could multiply that by a hundred thousand cores and it would still be negligible compared to the hundreds of millions likely to die due to climate change in the next century
    - ghostbrainalpha 5y ago
      I really liked how you framed the danger. But what about if we had a Reactor Dump storing 100's of these reactors, and then something happened to that dump, either it was hit by a meter or it was intentionally attacked in some way. Could that result in an apocalyptical type event?
      - concordDance 5y ago
        No, it couldn't. It would basically be a few Chernobyls in the worst case (a 1 in 1000 year asteroid impact winning the 1 in 100 million lottery and hitting the dump) and that mostly means extra birth defects and cancer (you wouldn't want to live somewhere that gave you a 10% chance if dying due to cancer age 40, but you could still have a civilization in such a location). It doesn't end life in the impacted area. For intentional attacks there are much much easier ways of killing a lot of people.
PaulHoule 5y ago
There are two problems. One is corrosion/radiation damage to the reactor vessel which is probably made with something like http://www.haynesintl.com/alloys/alloy-portfolio_/Corrosion-resistant-Alloys/hastelloy-n-alloy/principle-features http://www.haynesintl.com/alloys/alloy-portfolio_/Corrosion-... The other is that most of these designs have a graphite moderator, and the graphite gets damaged in the reactor environment.
- ortusdux 5y ago
  I would consider graphite moderators under the umbrella of salt facing components. High Ni alloys such as Hast-N have their own issues - mainly radiation induced Ni -> He embrittlement and tellurium embrittlement. That being said, they are very promising.

tehjoker 5y ago

Thorium reactors produce isotopes that can be converted into U238, which is less desirable than U235 for weapons purposes, but can be converted into a usable if annoying and expensive to manage bomb due to its high gamma production. https://www.foe.org.au/anti-nuclear/issues/nfc/power-weapons/thorium https://www.foe.org.au/anti-nuclear/issues/nfc/power-weapons...