14 ms·

I don't understand. One of the benefits of nuclear is that it can be turned on and off quite easily. There are several mechanisms to throttle on and off the rea

I don't understand. One of the benefits of nuclear is that it can be turned on and off quite easily. There are several mechanisms to throttle on and off the reaction.

laurent92 5y ago
Is this a new thing? In France, the nuclear plants built between 1960 and 1980 have throttling but it takes more than 20hrs to cool down, making it inefficient to stop at night (hence over-provisioning overnight leading to price shifts to encourage people to run water boilers and washing machines at night).
- catlikesshrimp 5y ago
  But what is so bad about encouraging people to schedule their energy expenditure? Charging the electric car during the night sounds like a no brainer for me. Same goes for the water heaters. The only heavy argument agaisnt nuclear is NIMBY.
  - laurent92 5y ago
    It makes it relevant to add solar during the day. This would allow reducing the baseline at night.
- MagnumOpus 5y ago
  This is a lie. The French reactors can throttle down from 100% capacity to 30% capacity (i.e. from 1300 MW to 400MW) within 30 minutes. Other countries can do the same if they build the option into their plant control (many do): https://www.powermag.com/flexible-operation-of-nuclear-power-plants-ramps-up/ https://www.powermag.com/flexible-operation-of-nuclear-power...
adrianN 5y ago
Capital expense for nuclear is so high that to be economical you need to run the plants at full power as much a possible. So while you can regulate them (slowly, there is quite a bit of thermal inertia in the system), it's much cheaper to regulate the renewables.
- koheripbal 5y ago
  China has proven that claim false. They hired western nuclear companies to build 20 nuclear plants in China. The high cost in the west is lawsuits and storage facility closures, and outdated regulations.
  - notreallyserio 5y ago
    How did China choose locations for their plants, and how did they convince folks there it was a good idea? What lessons should we take from them?
arrrg 5y ago
Sure, but you don’t want to do that. Nuclear is monstrously expensive already. For it to have any chance of being economically viable at all you have to run it all the time. It doesn’t make sense as an on-demand power source.
- malthuswaswrong 5y ago
  Nuclear is totally economically viable. It's not viable in the current regulatorily climate. Investing $1 billion in a nuclear plant that will return profits for 80 years is an easy financial decision. Investing $1 billion in a nuclear plant that will be shut down by moonbats every 4 years when the next batch of princess unicorns is voted into office is not economically viable.
  - nbraem 5y ago
    That is, if you leave the storage cost of the nuclear waste for the next 100.000 years out of your business model.
    - _3u10 5y ago
      There’s very little storage cost as the fuel can be burned til there is nothing radioactive left. Nuclear doesn’t produce radioactive materials it reduces radioactivity. If you mix the spent fuel from a heavy water reactor back into the ore, it’s radioactivity will have been reduced.
      - adrianN 5y ago
        While you can burn the fuel until very few long-lived isotopes are left we don't do that currently. Nuclear reactors also turn relatively harmless Uranium into much more active elements. Just mixing the waste back into the rocks you got the Uranium from is not a safe storage method.
        malthuswaswrong 5y ago
mnw21cam 5y ago
I'm an advocate for nuclear power, but I have to point out that this isn't actually true. A nuclear plant can load-follow to a certain extent if it is designed to do so, but if you reduce the power output of a nuclear reactor below a certain threshold then the reactor will need a decent period of time (around a day) to cool down before it can be started up again. The fundamental problem is nuclear physics itself. Running a nuclear reactor produces Xenon-135, which has a huge potential to soak up neutrons, and therefore given half a chance will try to shut down the nuclear reaction. When the reactor is going full pelt, then there are enough neutrons flying around to burn up the Xenon, and all is good. When you reduce power output, then there is still a large amount of Xenon in the reactor, and it will soak up lots of the neutrons and reactivity of the reactor, shutting the reaction down. The Xenon takes about a day to decay by itself down to a level where it is safe to restart the reactor again. See https://en.wikipedia.org/wiki/Xenon-135 https://en.wikipedia.org/wiki/Xenon-135 and https://en.wikipedia.org/wiki/Neutron_poison https://en.wikipedia.org/wiki/Neutron_poison One of the contributing factors towards the Chernobyl accident was the reactor controllers trying to overcome the effects of Xenon by pulling the control rods of the reactor out. This made the reactor highly unstable, because as the reaction rate increases the Xenon will be burned off increasing the reactivity, which can lead to the reaction ramping up very quickly.

I don't understand. One of the benefits of nuclear is that it can be turned on and off quite easily. There are several mechanisms to throttle on and off the reaction.

laurent92 5y ago

Is this a new thing? In France, the nuclear plants built between 1960 and 1980 have throttling but it takes more than 20hrs to cool down, making it inefficient to stop at night (hence over-provisioning overnight leading to price shifts to encourage people to run water boilers and washing machines at night).

catlikesshrimp 5y ago
But what is so bad about encouraging people to schedule their energy expenditure? Charging the electric car during the night sounds like a no brainer for me. Same goes for the water heaters. The only heavy argument agaisnt nuclear is NIMBY.
- laurent92 5y ago
  It makes it relevant to add solar during the day. This would allow reducing the baseline at night.
MagnumOpus 5y ago
This is a lie. The French reactors can throttle down from 100% capacity to 30% capacity (i.e. from 1300 MW to 400MW) within 30 minutes. Other countries can do the same if they build the option into their plant control (many do): https://www.powermag.com/flexible-operation-of-nuclear-power-plants-ramps-up/ https://www.powermag.com/flexible-operation-of-nuclear-power...

adrianN 5y ago

Capital expense for nuclear is so high that to be economical you need to run the plants at full power as much a possible. So while you can regulate them (slowly, there is quite a bit of thermal inertia in the system), it's much cheaper to regulate the renewables.

koheripbal 5y ago
China has proven that claim false. They hired western nuclear companies to build 20 nuclear plants in China. The high cost in the west is lawsuits and storage facility closures, and outdated regulations.
- notreallyserio 5y ago
  How did China choose locations for their plants, and how did they convince folks there it was a good idea? What lessons should we take from them?

arrrg 5y ago

Sure, but you don’t want to do that. Nuclear is monstrously expensive already. For it to have any chance of being economically viable at all you have to run it all the time. It doesn’t make sense as an on-demand power source.

malthuswaswrong 5y ago
Nuclear is totally economically viable. It's not viable in the current regulatorily climate. Investing $1 billion in a nuclear plant that will return profits for 80 years is an easy financial decision. Investing $1 billion in a nuclear plant that will be shut down by moonbats every 4 years when the next batch of princess unicorns is voted into office is not economically viable.
- nbraem 5y ago
  That is, if you leave the storage cost of the nuclear waste for the next 100.000 years out of your business model.
  - _3u10 5y ago
    There’s very little storage cost as the fuel can be burned til there is nothing radioactive left. Nuclear doesn’t produce radioactive materials it reduces radioactivity. If you mix the spent fuel from a heavy water reactor back into the ore, it’s radioactivity will have been reduced.
    - adrianN 5y ago
      While you can burn the fuel until very few long-lived isotopes are left we don't do that currently. Nuclear reactors also turn relatively harmless Uranium into much more active elements. Just mixing the waste back into the rocks you got the Uranium from is not a safe storage method.
      - malthuswaswrong 5y ago

mnw21cam 5y ago

I'm an advocate for nuclear power, but I have to point out that this isn't actually true. A nuclear plant can load-follow to a certain extent if it is designed to do so, but if you reduce the power output of a nuclear reactor below a certain threshold then the reactor will need a decent period of time (around a day) to cool down before it can be started up again. The fundamental problem is nuclear physics itself. Running a nuclear reactor produces Xenon-135, which has a huge potential to soak up neutrons, and therefore given half a chance will try to shut down the nuclear reaction. When the reactor is going full pelt, then there are enough neutrons flying around to burn up the Xenon, and all is good. When you reduce power output, then there is still a large amount of Xenon in the reactor, and it will soak up lots of the neutrons and reactivity of the reactor, shutting the reaction down. The Xenon takes about a day to decay by itself down to a level where it is safe to restart the reactor again. See https://en.wikipedia.org/wiki/Xenon-135 https://en.wikipedia.org/wiki/Xenon-135 and https://en.wikipedia.org/wiki/Neutron_poison https://en.wikipedia.org/wiki/Neutron_poison One of the contributing factors towards the Chernobyl accident was the reactor controllers trying to overcome the effects of Xenon by pulling the control rods of the reactor out. This made the reactor highly unstable, because as the reaction rate increases the Xenon will be burned off increasing the reactivity, which can lead to the reaction ramping up very quickly.