6 ms·

It's not a given that the water flows that are required to cool the reactors are going to be present in the fall/winter.

ars 4y ago
It's not usually a waterflow issue, rather water that is too warm to cool the reactor. This won't be a problem in the winter. And in the future they'll probably design the reactors to handle the warmer water, or even run without water (lower efficiency, but that's not really an issue for nuclear).
- lucb1e 4y ago
  If that's the case, why is the electricity company (per the article) saying they'll have the shortfalls down to a quarter (I take that to mean 75% of normal generation capacity, not 25%) by December? And why is the market not even buying that, what is the logic there (be it correct or not)? --- Edit: a sibling comment https://news.ycombinator.com/item?id=32443994 https://news.ycombinator.com/item?id=32443994 has answered the below question. It's not the water input that is the problem, but the water output temperature for ecological reasons. Original text: As a less-important aside, I'm also surprised a change in water temperature of like 20°K/C/F makes a noticeable difference on a reactor running afaik at some thousands of degrees. If anyone has a pointer or tldr for that, I'd be curious to learn why.
  - ars 4y ago
    It's not water at all - usually high water temperatures are just a few days a year. There's something else going on - I saw mention of corrosion, but I don't really know.
- shakow 4y ago
  > rather water that is too warm to cool the reactor. No, it is still cold enough to cool the reactor. They can't use it because the warm water that the plant would release would be too warm w.r.t. ecological regulations. If for some reason the plant had to work right now, it could still do it, but would damage the downstream ecosystem.
  - Nasrudith 4y ago
    Isn't that what cooling towers are for? An alternative to warm water emissions. I am no expert admittedly.
    - shakow 4y ago
      They are, but not all nuke plant feature cooling towers. The problem here is for those without: they use water as a cooling fluid, but then just pour it back into the river instead of evaporating it. The advantage is that they don't consume/move the water, the inconvenient is that they can't spit out 40C water without hurting the river's ecosystem.
      - ars 4y ago
        It's not 40C at all! It's only a 2 of 3 degrees more than it started. Water temperature issues are very rare, and only happen a couple days out of the year.
  - Manuel_D 4y ago
    Are the ecological impacts of warm water seriously worth the increase in fossil fuels from reducing nuclear output? This seems like a nuclear-obstructionist kind of environmental policy.

ars 4y ago

It's not usually a waterflow issue, rather water that is too warm to cool the reactor. This won't be a problem in the winter. And in the future they'll probably design the reactors to handle the warmer water, or even run without water (lower efficiency, but that's not really an issue for nuclear).

lucb1e 4y ago
If that's the case, why is the electricity company (per the article) saying they'll have the shortfalls down to a quarter (I take that to mean 75% of normal generation capacity, not 25%) by December? And why is the market not even buying that, what is the logic there (be it correct or not)? --- Edit: a sibling comment https://news.ycombinator.com/item?id=32443994 https://news.ycombinator.com/item?id=32443994 has answered the below question. It's not the water input that is the problem, but the water output temperature for ecological reasons. Original text: As a less-important aside, I'm also surprised a change in water temperature of like 20°K/C/F makes a noticeable difference on a reactor running afaik at some thousands of degrees. If anyone has a pointer or tldr for that, I'd be curious to learn why.
- ars 4y ago
  It's not water at all - usually high water temperatures are just a few days a year. There's something else going on - I saw mention of corrosion, but I don't really know.
shakow 4y ago
> rather water that is too warm to cool the reactor. No, it is still cold enough to cool the reactor. They can't use it because the warm water that the plant would release would be too warm w.r.t. ecological regulations. If for some reason the plant had to work right now, it could still do it, but would damage the downstream ecosystem.
- Nasrudith 4y ago
  Isn't that what cooling towers are for? An alternative to warm water emissions. I am no expert admittedly.
  - shakow 4y ago
    They are, but not all nuke plant feature cooling towers. The problem here is for those without: they use water as a cooling fluid, but then just pour it back into the river instead of evaporating it. The advantage is that they don't consume/move the water, the inconvenient is that they can't spit out 40C water without hurting the river's ecosystem.
    - ars 4y ago
      It's not 40C at all! It's only a 2 of 3 degrees more than it started. Water temperature issues are very rare, and only happen a couple days out of the year.
- Manuel_D 4y ago
  Are the ecological impacts of warm water seriously worth the increase in fossil fuels from reducing nuclear output? This seems like a nuclear-obstructionist kind of environmental policy.