4 ms·

"Too Expensive, Too Slow, and Too Risky" Because they are still too big. They must be very small. Fuel efficiency is less important than creating economies o

"Too Expensive, Too Slow, and Too Risky" Because they are still too big. They must be very small. Fuel efficiency is less important than creating economies of scale in manufacturing.

lven 2y ago
not when it's more expensive than diesel. Must find the balance.
- TheDudeMan 2y ago
  Nuclear fuel is about 20x cheaper than diesel (per unit energy). https://www.osti.gov/servlets/purl/840500 https://www.osti.gov/servlets/purl/840500 (page 6, table VII)
Arnt 2y ago
Can a nuclear reactor be small enough that it doesn't need an expensive fence with 24/7 guards, and an expensive evaluation of the site for disaster risk? I sort of suspect the answer to be no, but would like to hear arguments for yes.
- littlestymaar 2y ago
  > doesn't need an expensive fence with 24/7 guards You means, like most industrial plants anyway or even college campuses? An “expensive fence” and 24/7 security guard are still ridiculously cheap compared to the price of the thing itself.
  - worik 2y ago
    > like most industrial plants anyway or even college campuses? Nuclear power stations are an extreme, not typical, example
    - littlestymaar 2y ago
      This is in fact purely a political decision: a nuclear power plant is in reality less prone to being attacked than a virology lab, and the consequences are way less severe [1], then why should we expect the former to have much more stringent security rules? [1] unless you leave the nuclear reactor unattended in the hands of terrorists for days, they won't be able to extract any nuclear material (which would be the worse case scenario and only one comparable to terrorist stealing a vial of Ebola or Smallpox)
  - consumer451 2y ago
    I believe that after 9/11, we required all new nuclear plants to be able to withstand the impact of a 737. So it's just a little more complicated.
    - AlexAndScripts 2y ago
      Perhaps it could be underground, either in an excavated area or a natural cave?
    - bialpio 2y ago
      How much (little?) radioactive material would there have to be inside the SMR for an impact of a 737 into the neighborhood to be more devastating than the release of the radioactive material?
      - consumer451 2y ago
        Well, this doesn't answer your question, but there is also the issue of waste storage. In light water reactors, that's stored on-site for a long time. This research appears to indicate that with SMRs, this is actually a bigger issue. > Small modular reactors (SMRs), proposed as the future of nuclear energy, have purported cost and safety advantages over existing gigawatt-scale light water reactors (LWRs). However, few studies have assessed the implications of SMRs for the back end of the nuclear fuel cycle. The low-, intermediate-, and high-level waste stream characterization presented here reveals that SMRs will produce more voluminous and chemically/physically reactive waste than LWRs, which will impact options for the management and disposal of this waste. Although the analysis focuses on only three of dozens of proposed SMR designs, the intrinsically higher neutron leakage associated with SMRs suggests that most designs are inferior to LWRs with respect to the generation, management, and final disposal of key radionuclides in nuclear waste. https://www.pnas.org/doi/10.1073/pnas.2111833119 https://www.pnas.org/doi/10.1073/pnas.2111833119
    - amluto 2y ago
      Off the top of my head, if I had to protect a shipping container sized object from a 737, I would bury it. Dig a hole maybe the size of a residential swimming pool, build some drainage and some concrete walls with enough space to allow the container to get back out, stick the container in, and backfill outside the walls. Put a lid on it and cover it with local soil. As a bonus: anyone trying to steal it would need an excavator of some sort. Or build an underground parking lot, park the SMR in it, put a serious door in front, and use the space above it for something else. Conventional construction underground, especially of something complex, is expensive. But much of the point of an SMR is that it’s built off site and then installed. Driving a container down a ramp or lowering one off a crane is straightforward.
- marcosdumay 2y ago
  You should be able to make a reactor with anything larger than a couple kg of material. Maybe you can avoid a thorium reactor if that size from being a valuable target. I have little idea about the social risks of somebody using the material as poison, instead of explosive, but I suspect it's incredibly overblown currently. (Wannabe thieves are probably way more effective going after something else.) But well, don't expect very small reactors to be efficient or cheap. They maybe could be cheap heat sources, but electricity generation and distribution are full of scale efficiencies.
  - pfdietz 2y ago
    > You should be able to make a reactor with anything larger than a couple kg of material. A reactor that small needs highly enriched fissionable material. Of course it would need guards, since it's a proliferation nightmare.
  - throwup238 2y ago
    The lower limit is a nuclear lightbulb with ~20kg of uranium fuel, but that’s a high pressure reactor chamber that would definitely need to be protected and it needs large centrifuges inline to separate the fuel back out from the gas.
  - TheDudeMan 2y ago
    You don't need distribution for a small enough reactor -- you use the electricity on site.
- anothernewdude 2y ago
  Small enough to be inserted into the human body to power a pacemaker.
  - pfdietz 2y ago
    That's not a nuclear reactor.
- TheDudeMan 2y ago
  Ideally, the reactor would not need service until end-of-life (e.g. ~10 years). That way, it can be encased in concrete and buried.
  - cyberax 2y ago
    Yeah, so basically, you want to spam the world with nuclear waste.
    - JumpCrisscross 2y ago
      > spam the world with nuclear waste You may be vastly underestimating the amount of toxic waste produced by our energy production processes, renewable or not. (Wind, as I understand it, being the least nasty.)
      - cyberax 2y ago
        The proposal is: > Ideally, the reactor would not need service until end-of-life (e.g. ~10 years). That way, it can be encased in concrete and buried. This will blow up the level of radioactive waste that needs to be buried by about 1000x. Instead of a couple of kilos of long-lived isotopes after reprocessing, you'll need to bury THE WHOLE FREAKING REACTOR CORE.
        JumpCrisscross 2y ago
        > blow up the level of radioactive waste that needs to be buried by about 1000x. Instead of a couple of kilos of long-lived isotopes after reprocessing, you'll need to bury THE WHOLE FREAKING REACTOR CORE Why the scare caps? The first word in SMR is “small.” We currently wash out the industrial waste from processing and manufacturing our energy inputs and infrastructure. Also, nothing stops reprocessing those cores in the future. Next to a spent-fuel tank or tailings pool, a buried core seems preferable.
        cyberax 2y ago
littlestymaar 2y ago
The argument about cost in this paper is complete bullshit anyway, since they are talking about one-shot reactors, of course it's going to be expensive, the main argument about SMR is that you're able to create multiple ones and improve the process to drive cost low as the learning curves kicks in (and without needing the kind of All-in France did in the 80s when they built 58 regular-sized reactor in 20 years, leading to very good economies of scale).
- worik 2y ago
  > the main argument about SMR is that you're able to create multiple ones and improve the process to drive cost low as the learning curves kicks in I was thinking that too. But they addressed that in the article Why will this time be different, when nowhere in the world has any nuclear industry succeeded in lowering costs over the life of a programme? The French, the article says, built 55 reactors, standardising the parts and processes but still could not control costs
  - cyberax 2y ago
    > Why will this time be different, when nowhere in the world has any nuclear industry succeeded in lowering costs over the life of a programme? Russia (Rosatom) did it with the exported reactors. China is on track as well, although their finances are not as transparent.
  - littlestymaar 2y ago
    > The French, the article says, built 58 (ftfy) reactors, standardizing the parts and processes but still could not control costs This is crazy bad faith at play here! Between the start of the French nuclear program and the end, two major international accident (TMI and Chornobyl) occurred and lead to massive changes in safety regulations. Of course it's going to have an impact on costs! Also, in the meantime there had been a huge return on operation experience, which allowed to design plants that became cheaper and more efficient to operate (load following is much easier on the second generation than on the first for instance) but obvious lead to changes in design, but that's still part of the learning curve.
  - 2y ago

"Too Expensive, Too Slow, and Too Risky" Because they are still too big. They must be very small. Fuel efficiency is less important than creating economies of scale in manufacturing.

lven 2y ago

not when it's more expensive than diesel. Must find the balance.

TheDudeMan 2y ago
Nuclear fuel is about 20x cheaper than diesel (per unit energy). https://www.osti.gov/servlets/purl/840500 https://www.osti.gov/servlets/purl/840500 (page 6, table VII)

Arnt 2y ago

Can a nuclear reactor be small enough that it doesn't need an expensive fence with 24/7 guards, and an expensive evaluation of the site for disaster risk? I sort of suspect the answer to be no, but would like to hear arguments for yes.

littlestymaar 2y ago
> doesn't need an expensive fence with 24/7 guards You means, like most industrial plants anyway or even college campuses? An “expensive fence” and 24/7 security guard are still ridiculously cheap compared to the price of the thing itself.
- worik 2y ago
  > like most industrial plants anyway or even college campuses? Nuclear power stations are an extreme, not typical, example
  - littlestymaar 2y ago
    This is in fact purely a political decision: a nuclear power plant is in reality less prone to being attacked than a virology lab, and the consequences are way less severe [1], then why should we expect the former to have much more stringent security rules? [1] unless you leave the nuclear reactor unattended in the hands of terrorists for days, they won't be able to extract any nuclear material (which would be the worse case scenario and only one comparable to terrorist stealing a vial of Ebola or Smallpox)
- consumer451 2y ago
  I believe that after 9/11, we required all new nuclear plants to be able to withstand the impact of a 737. So it's just a little more complicated.
  - AlexAndScripts 2y ago
    Perhaps it could be underground, either in an excavated area or a natural cave?
  - bialpio 2y ago
    How much (little?) radioactive material would there have to be inside the SMR for an impact of a 737 into the neighborhood to be more devastating than the release of the radioactive material?
    - consumer451 2y ago
      Well, this doesn't answer your question, but there is also the issue of waste storage. In light water reactors, that's stored on-site for a long time. This research appears to indicate that with SMRs, this is actually a bigger issue. > Small modular reactors (SMRs), proposed as the future of nuclear energy, have purported cost and safety advantages over existing gigawatt-scale light water reactors (LWRs). However, few studies have assessed the implications of SMRs for the back end of the nuclear fuel cycle. The low-, intermediate-, and high-level waste stream characterization presented here reveals that SMRs will produce more voluminous and chemically/physically reactive waste than LWRs, which will impact options for the management and disposal of this waste. Although the analysis focuses on only three of dozens of proposed SMR designs, the intrinsically higher neutron leakage associated with SMRs suggests that most designs are inferior to LWRs with respect to the generation, management, and final disposal of key radionuclides in nuclear waste. https://www.pnas.org/doi/10.1073/pnas.2111833119 https://www.pnas.org/doi/10.1073/pnas.2111833119
  - amluto 2y ago
    Off the top of my head, if I had to protect a shipping container sized object from a 737, I would bury it. Dig a hole maybe the size of a residential swimming pool, build some drainage and some concrete walls with enough space to allow the container to get back out, stick the container in, and backfill outside the walls. Put a lid on it and cover it with local soil. As a bonus: anyone trying to steal it would need an excavator of some sort. Or build an underground parking lot, park the SMR in it, put a serious door in front, and use the space above it for something else. Conventional construction underground, especially of something complex, is expensive. But much of the point of an SMR is that it’s built off site and then installed. Driving a container down a ramp or lowering one off a crane is straightforward.
marcosdumay 2y ago
You should be able to make a reactor with anything larger than a couple kg of material. Maybe you can avoid a thorium reactor if that size from being a valuable target. I have little idea about the social risks of somebody using the material as poison, instead of explosive, but I suspect it's incredibly overblown currently. (Wannabe thieves are probably way more effective going after something else.) But well, don't expect very small reactors to be efficient or cheap. They maybe could be cheap heat sources, but electricity generation and distribution are full of scale efficiencies.
- pfdietz 2y ago
  > You should be able to make a reactor with anything larger than a couple kg of material. A reactor that small needs highly enriched fissionable material. Of course it would need guards, since it's a proliferation nightmare.
- throwup238 2y ago
  The lower limit is a nuclear lightbulb with ~20kg of uranium fuel, but that’s a high pressure reactor chamber that would definitely need to be protected and it needs large centrifuges inline to separate the fuel back out from the gas.
- TheDudeMan 2y ago
  You don't need distribution for a small enough reactor -- you use the electricity on site.
anothernewdude 2y ago
Small enough to be inserted into the human body to power a pacemaker.
- pfdietz 2y ago
  That's not a nuclear reactor.
TheDudeMan 2y ago
Ideally, the reactor would not need service until end-of-life (e.g. ~10 years). That way, it can be encased in concrete and buried.
- cyberax 2y ago
  Yeah, so basically, you want to spam the world with nuclear waste.
  - JumpCrisscross 2y ago
    > spam the world with nuclear waste You may be vastly underestimating the amount of toxic waste produced by our energy production processes, renewable or not. (Wind, as I understand it, being the least nasty.)
    - cyberax 2y ago
      The proposal is: > Ideally, the reactor would not need service until end-of-life (e.g. ~10 years). That way, it can be encased in concrete and buried. This will blow up the level of radioactive waste that needs to be buried by about 1000x. Instead of a couple of kilos of long-lived isotopes after reprocessing, you'll need to bury THE WHOLE FREAKING REACTOR CORE.
      - JumpCrisscross 2y ago
        > blow up the level of radioactive waste that needs to be buried by about 1000x. Instead of a couple of kilos of long-lived isotopes after reprocessing, you'll need to bury THE WHOLE FREAKING REACTOR CORE Why the scare caps? The first word in SMR is “small.” We currently wash out the industrial waste from processing and manufacturing our energy inputs and infrastructure. Also, nothing stops reprocessing those cores in the future. Next to a spent-fuel tank or tailings pool, a buried core seems preferable.
        cyberax 2y ago

littlestymaar 2y ago

The argument about cost in this paper is complete bullshit anyway, since they are talking about one-shot reactors, of course it's going to be expensive, the main argument about SMR is that you're able to create multiple ones and improve the process to drive cost low as the learning curves kicks in (and without needing the kind of All-in France did in the 80s when they built 58 regular-sized reactor in 20 years, leading to very good economies of scale).

worik 2y ago
> the main argument about SMR is that you're able to create multiple ones and improve the process to drive cost low as the learning curves kicks in I was thinking that too. But they addressed that in the article Why will this time be different, when nowhere in the world has any nuclear industry succeeded in lowering costs over the life of a programme? The French, the article says, built 55 reactors, standardising the parts and processes but still could not control costs
- cyberax 2y ago
  > Why will this time be different, when nowhere in the world has any nuclear industry succeeded in lowering costs over the life of a programme? Russia (Rosatom) did it with the exported reactors. China is on track as well, although their finances are not as transparent.
- littlestymaar 2y ago
  > The French, the article says, built 58 (ftfy) reactors, standardizing the parts and processes but still could not control costs This is crazy bad faith at play here! Between the start of the French nuclear program and the end, two major international accident (TMI and Chornobyl) occurred and lead to massive changes in safety regulations. Of course it's going to have an impact on costs! Also, in the meantime there had been a huge return on operation experience, which allowed to design plants that became cheaper and more efficient to operate (load following is much easier on the second generation than on the first for instance) but obvious lead to changes in design, but that's still part of the learning curve.
- 2y ago