4 ms·

Nuclear is emphatically not an instant-on hot backup. Plants take time to spool up, and very importantly time to cool down. Fukushima happened because you can

by ajross 3y ago

Nuclear is emphatically not an instant-on hot backup. Plants take time to spool up, and very importantly time to cool down. Fukushima happened because you can't just turn a reactor off, it produces energy that has to go somewhere while the intermediate fission products decay over hours-to-days.

avar 3y ago
In this scenario you could just run the nuclear plant all the time, but just direct its electric production to heating a giant pool of water or whatever. Then when the grid needs more power you do less of that, and instead send electricity to the grid.
- tuatoru 3y ago
  Electrolyzing water to make hydrogen for ammonia (fertilizer) and industrial chemical feed stocks, please.
- acchow 3y ago
  Or powering GPU compute centers. When the grid needs more power, these dynamically power down (raise LLM generation prices)
- ajross 3y ago
  Yes, but the point is that the problem is isomorphic to wind or solar: you get power when you don't want it. So nuclear isn't backstopping any particular need, it has the same drawbacks. The reason gas plants are used as peaker plants is that they can be turned on and off more or less instantly.
  - avar 3y ago
    You're just assigning magical value to "turn it off". That's only a big deal with fossil fuels due to the fuel cost, the fuel cost of nuclear is marginal. Yes, I agree that it's stupid to build a (big) nuclear power plant only to use it to boil an Olympic sized swimming pool most of the time. But that's stupid because we're over-relying on "green" energy that can't provide baseload power. It's even more stupid with fossil fuels, now you also need an entirely different backup infrastructure, but the fossil one pollutes much more than nuclear.
    - hnaccount_rng 3y ago
      The problem with your logic is, that nuclear is _only_ competitive with a 100% utilization rate/capacity factor. Only with these 90+% capacity factors do you get to competitive rates per kWh produced. Otherwise the initial CapEx is just too large, especially in a non-zero rate environment, as these plants are _already_ scoped/calculated/financed to 40 years. At 90+% capacity factor! That amount of CapEx is basically impossible without either very high earning potential (that’s why TSMC works. Everyone will just pay their price) or government backing (because then you don’t have to care about financing and optionality costs and can just pay for it with taxes). Neither one will be possible, at least in western societies (And yes this ignores a certain amount of externalities, like the tendency of requiring large scale evacuations in their surroundings every second decade, but we can set that aside, as it’s irrelevant for the economic argument above)
      - phil21 3y ago
        At some point society will realize comparing power pricing to the lowest cost per kwh on a given day is a silly waste of time. What matters is what is the most realistic mix of power generation and storage for 24x7 reliability. This can of course look very different depending on the situation. Many will argue for distributed storage (e.g. home batteries) - but that just means poor people don't get reliable electric service. I really don't find that solar is "too cheap to meter" during peak sunlight very interesting. Who cares. What I find interesting is that I can turn a dial on my nuclear power plant to whatever it is I feel like at any time, and have it operating at that capacity within an hour or three. Since we have such a dial, if you owned both the solar and the nuclear plants you would very likely combine them in a manner that maximizes profits while maintaining continuous service. Short of clouds, regional solar and wind prediction is extremely good to the point that modern nuclear plants may as well be load following. Add in a bit of battery for those minutes (hours max) that surprise you and you're good to go on that front. You still will need some gas peaker plants for those crazy once-in-a-decade days you don't want to overbuild nuclear capacity for, but you could drastically reduce this infrastructure from what is effectively a 1:1 ratio today.
      - avar 3y ago
deleted 3y ago
[deleted]
troupo 3y ago
> Nuclear is emphatically not an instant-on hot backup. Plants take time to spool up, and very importantly time to cool down All modern nuclear plants work in load following mode with ability to change ant the rate of 3-5% of their rated capacity per minute. Graph and text on page 8: https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... > Fukushima happened because you can't just turn a reactor off, Fukushima happened because the plant was hit with both an earthquake and a flood significantly exceeding its operational parameters (already extremely high)
- VaxWithSex 3y ago
  Nobody seems to get that these operational parameters were set and approved and told to be save and then they were still exceeded, lol.
  - troupo 3y ago
    This was literally the definition of a black swan event: "an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight"
    - hef19898 3y ago
      No, Japanese authorities and TEPCo knew tgat earthquakes and tsunamis could happen, and usually together. They planned for it, they simply planned insufficiently, so quite the opposite of a black swan.
      - troupo 3y ago
        The definition of a catastrophic one-in-a-lifetime event: you can't plan for it. Fukushima had been in operation since 1971. You truly really believe that there were no earthquakes in the meantime, and the only reason for failure in 2011 is that they didn't plan for the largest earthquake and one of the worst tsunamis in Japanese history?

by ajross 3y ago

avar 3y ago

In this scenario you could just run the nuclear plant all the time, but just direct its electric production to heating a giant pool of water or whatever. Then when the grid needs more power you do less of that, and instead send electricity to the grid.

tuatoru 3y ago
Electrolyzing water to make hydrogen for ammonia (fertilizer) and industrial chemical feed stocks, please.
acchow 3y ago
Or powering GPU compute centers. When the grid needs more power, these dynamically power down (raise LLM generation prices)
ajross 3y ago
Yes, but the point is that the problem is isomorphic to wind or solar: you get power when you don't want it. So nuclear isn't backstopping any particular need, it has the same drawbacks. The reason gas plants are used as peaker plants is that they can be turned on and off more or less instantly.
- avar 3y ago
  You're just assigning magical value to "turn it off". That's only a big deal with fossil fuels due to the fuel cost, the fuel cost of nuclear is marginal. Yes, I agree that it's stupid to build a (big) nuclear power plant only to use it to boil an Olympic sized swimming pool most of the time. But that's stupid because we're over-relying on "green" energy that can't provide baseload power. It's even more stupid with fossil fuels, now you also need an entirely different backup infrastructure, but the fossil one pollutes much more than nuclear.
  - hnaccount_rng 3y ago
    The problem with your logic is, that nuclear is _only_ competitive with a 100% utilization rate/capacity factor. Only with these 90+% capacity factors do you get to competitive rates per kWh produced. Otherwise the initial CapEx is just too large, especially in a non-zero rate environment, as these plants are _already_ scoped/calculated/financed to 40 years. At 90+% capacity factor! That amount of CapEx is basically impossible without either very high earning potential (that’s why TSMC works. Everyone will just pay their price) or government backing (because then you don’t have to care about financing and optionality costs and can just pay for it with taxes). Neither one will be possible, at least in western societies (And yes this ignores a certain amount of externalities, like the tendency of requiring large scale evacuations in their surroundings every second decade, but we can set that aside, as it’s irrelevant for the economic argument above)
    - phil21 3y ago
      At some point society will realize comparing power pricing to the lowest cost per kwh on a given day is a silly waste of time. What matters is what is the most realistic mix of power generation and storage for 24x7 reliability. This can of course look very different depending on the situation. Many will argue for distributed storage (e.g. home batteries) - but that just means poor people don't get reliable electric service. I really don't find that solar is "too cheap to meter" during peak sunlight very interesting. Who cares. What I find interesting is that I can turn a dial on my nuclear power plant to whatever it is I feel like at any time, and have it operating at that capacity within an hour or three. Since we have such a dial, if you owned both the solar and the nuclear plants you would very likely combine them in a manner that maximizes profits while maintaining continuous service. Short of clouds, regional solar and wind prediction is extremely good to the point that modern nuclear plants may as well be load following. Add in a bit of battery for those minutes (hours max) that surprise you and you're good to go on that front. You still will need some gas peaker plants for those crazy once-in-a-decade days you don't want to overbuild nuclear capacity for, but you could drastically reduce this infrastructure from what is effectively a 1:1 ratio today.
    - avar 3y ago

deleted 3y ago

[deleted]

troupo 3y ago

> Nuclear is emphatically not an instant-on hot backup. Plants take time to spool up, and very importantly time to cool down All modern nuclear plants work in load following mode with ability to change ant the rate of 3-5% of their rated capacity per minute. Graph and text on page 8: https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... > Fukushima happened because you can't just turn a reactor off, Fukushima happened because the plant was hit with both an earthquake and a flood significantly exceeding its operational parameters (already extremely high)

VaxWithSex 3y ago
Nobody seems to get that these operational parameters were set and approved and told to be save and then they were still exceeded, lol.
- troupo 3y ago
  This was literally the definition of a black swan event: "an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight"
  - hef19898 3y ago
    No, Japanese authorities and TEPCo knew tgat earthquakes and tsunamis could happen, and usually together. They planned for it, they simply planned insufficiently, so quite the opposite of a black swan.
    - troupo 3y ago
      The definition of a catastrophic one-in-a-lifetime event: you can't plan for it. Fukushima had been in operation since 1971. You truly really believe that there were no earthquakes in the meantime, and the only reason for failure in 2011 is that they didn't plan for the largest earthquake and one of the worst tsunamis in Japanese history?