7 ms·

Well, it does. Nuclear plants have very high embodied carbon, as they're made out of large amounts of steel and concrete. That's obviously not as bad as a coal

Well, it does. Nuclear plants have very high embodied carbon, as they're made out of large amounts of steel and concrete. That's obviously not as bad as a coal plant or even a gas plant. But 'a lot' is still probably correct.

tremon 4y ago
By that reasoning, a wind park isn't carbon-free electricity either. I wish you good luck on your campaign to convince the public, after that you can come back here and we'll talk again.
- cinntaile 4y ago
  If we just look at how much CO2 something produces when it's ready-built we potentially ignore a huge part of the pollution. You usually do a life cycle analysis (LCA) and come up with a g CO2-equivalents/kWh. No energy source has 0g/kWh.
  - Schroedingersat 4y ago
    Not to defend nuclear, but it's competitive with solar on that front and better than anything but hydro. Keeping existing nuclear on as long as it's safe is a pretty clear win climate-wise
triceratops 4y ago
Can a nuclear plant produce enough energy to capture all the carbon emitted in its construction? While still being profitable, obviously.
- pasabagi 4y ago
  Just thinking the problem through, I think that's very unlikely, unless you're in a pathological situation. So, for a nuclear plant to be profitable in a competitive market, it needs to produce energy for less than its competitors. If its competitors don't have to pay to capture carbon (through money or output) then they are always going to be cheaper per watt, and the plant is going to become unprofitable. The only way that would work is if you had chronic electricity undersupply (v. likely but also pathological) or if nuclear plants were way more efficient than alternatives (the opposite is true). Generally the argument for nuclear is you need a diverse range of energy sources to have a stable power supply, not that they are a great 'bang-for-buck' option. (An argument I agree with, fwiw). EDIT, PS: It's worth keeping in mind that carbon capture is largely an unsolved technical problem, and I think it's perfectly feasible that it will never be solved. The basic idea of burning fossil fuels for energy, then using energy to recoup the carbon from the atmosphere, just makes no sense at all. There's no world where this would be cheaper than just not releasing the CO2 in the first place.
  - DuskStar 4y ago
    If you made all the alternatives also pay to capture their carbon cost, I think nuclear would be very competitive. Obviously it blows fossil fuels out of the water, but hydroelectric also uses huge amounts of concrete, and IIRC the energy return on investment (MWh you get out per MWh it takes to construct) for solar and wind is quite poor and so I'd expect that to take a while to pay off too.
    - Retric 4y ago
      Nuclear has a vastly worse EROI than grid PV solar. Nuclear lasts longer which somewhat offsets construction costs, but needs a vast workforce continually and a maintenance and power simply to operate. As a sanity check, sub 2c/KWh solar can’t require that much energy simply because energy costs money. Nuclear on the other hand ends up having ~1,000 workers drive somewhere for 50 years which also takes energy, but that’s often ignored. That said, people love to come up with all kinds of irrelevant comparisons using vastly outdated data to make things look worse for solar while ignoring Nuclear’s downsides. For example France’s capacity factor fell below 70% when they tried to ramp up production and things would look even worse on a 100% nuclear grid.
      - cinntaile 4y ago
        It seems highly unlikely that grid PV solar has a higher EROI than nuclear and I can't find anything that supports this either (I find plenty of graphs supporting the opposite).
        Schroedingersat 4y ago
        Most of those are from fossil fuel or nuclear shills. You can get wildly varying numbers based on what you include and exclude. Meta analyses say current/upcoming techs are about as good or maybe a bit better, but energy payback time is significantly lower due to reduced lifetime. Additionally the GHG impact of nuclearand wind isn't quite proportional to energy payback time because of concrete. https://ieeexplore.ieee.org/document/8118077 https://ieeexplore.ieee.org/document/8118077 https://www.sciencedirect.com/science/article/pii/S0301421513003856 https://www.sciencedirect.com/science/article/pii/S030142151... Really though the answer is both are fine and nuclear probably wins once you include a mix of wind, hydro and storage. And embodied emissions will go down as low carbon energy becomes a bigger share. The main arguments against new nuclear are political (making new oil barons but with nuclear is stupid among other problems) and opportunity cost (using a nuclear reactor to replace 1GW of fossil fuels 80% of the time uses the same resources as using renewables to replace 10GW of fossil fuels ~40% of the time -- some of which is uncorrelated -- but at much longer delay).
- himinlomax 4y ago
  Several orders of magnitude over, yes.
- deleted 4y ago
  [deleted]
- Schroedingersat 4y ago
  This is loosely measured by EROI (energy return on invested). Concrete muddies the water slightly as it's a non-energy ghg emitter. The answer is definitely to the first part. By what ratio depends on who you ask. The nuclear lobby claims 50-80x. Most other people say it's in the 10-20x range. This is about as good as to somewhat better than wind, but at some point between 2012 and 2030 solar has surpassed/is going to surpass it by whichever measure you choose. Of course once the steel/silicon/composite/etc comes from low carbon sources, then the embodied carbon reduces as well. To the second part (while being profitable), no new nuclear build can be profitable, so no.
cinntaile 4y ago
Over their 40+ years lifetime it becomes negligible.
- pasabagi 4y ago
  Maybe? Because climate change is a self-feeding cycle, releasing large amounts of CO2 early, then amortizing that over decades of operation, is worse than a constant steady release. I guess you're probably right, nonetheless. It just annoys me when people post polls like this to prove that people in general are stupid, when polls generally show that ordinary people everywhere are way better on climate issues than political elites.
  - petre 4y ago
    Concrete absorbs CO2 as it cures. If you add a bit of titanium dioxide it doubles the amount of absorbed CO2.
sanp 4y ago
But that’s sunk cost. That’s not increasing with consumption unless u get to a point where u have to build a new plant.
credit_guy 4y ago
This is incorrect. A large nuclear power plant uses about 200000 cubic meters of concrete. Each m3 of concrete contributes about half a ton of CO2 emissions, so that’s a one time 0.1 MT of CO2 emissions. A coal power plant of similar size will emit more than 1 MT every - single - year. There is simply no comparison.

tremon 4y ago

By that reasoning, a wind park isn't carbon-free electricity either. I wish you good luck on your campaign to convince the public, after that you can come back here and we'll talk again.

cinntaile 4y ago
If we just look at how much CO2 something produces when it's ready-built we potentially ignore a huge part of the pollution. You usually do a life cycle analysis (LCA) and come up with a g CO2-equivalents/kWh. No energy source has 0g/kWh.
- Schroedingersat 4y ago
  Not to defend nuclear, but it's competitive with solar on that front and better than anything but hydro. Keeping existing nuclear on as long as it's safe is a pretty clear win climate-wise

triceratops 4y ago

Can a nuclear plant produce enough energy to capture all the carbon emitted in its construction? While still being profitable, obviously.

pasabagi 4y ago
Just thinking the problem through, I think that's very unlikely, unless you're in a pathological situation. So, for a nuclear plant to be profitable in a competitive market, it needs to produce energy for less than its competitors. If its competitors don't have to pay to capture carbon (through money or output) then they are always going to be cheaper per watt, and the plant is going to become unprofitable. The only way that would work is if you had chronic electricity undersupply (v. likely but also pathological) or if nuclear plants were way more efficient than alternatives (the opposite is true). Generally the argument for nuclear is you need a diverse range of energy sources to have a stable power supply, not that they are a great 'bang-for-buck' option. (An argument I agree with, fwiw). EDIT, PS: It's worth keeping in mind that carbon capture is largely an unsolved technical problem, and I think it's perfectly feasible that it will never be solved. The basic idea of burning fossil fuels for energy, then using energy to recoup the carbon from the atmosphere, just makes no sense at all. There's no world where this would be cheaper than just not releasing the CO2 in the first place.
- DuskStar 4y ago
  If you made all the alternatives also pay to capture their carbon cost, I think nuclear would be very competitive. Obviously it blows fossil fuels out of the water, but hydroelectric also uses huge amounts of concrete, and IIRC the energy return on investment (MWh you get out per MWh it takes to construct) for solar and wind is quite poor and so I'd expect that to take a while to pay off too.
  - Retric 4y ago
    Nuclear has a vastly worse EROI than grid PV solar. Nuclear lasts longer which somewhat offsets construction costs, but needs a vast workforce continually and a maintenance and power simply to operate. As a sanity check, sub 2c/KWh solar can’t require that much energy simply because energy costs money. Nuclear on the other hand ends up having ~1,000 workers drive somewhere for 50 years which also takes energy, but that’s often ignored. That said, people love to come up with all kinds of irrelevant comparisons using vastly outdated data to make things look worse for solar while ignoring Nuclear’s downsides. For example France’s capacity factor fell below 70% when they tried to ramp up production and things would look even worse on a 100% nuclear grid.
    - cinntaile 4y ago
      It seems highly unlikely that grid PV solar has a higher EROI than nuclear and I can't find anything that supports this either (I find plenty of graphs supporting the opposite).
      - Schroedingersat 4y ago
        Most of those are from fossil fuel or nuclear shills. You can get wildly varying numbers based on what you include and exclude. Meta analyses say current/upcoming techs are about as good or maybe a bit better, but energy payback time is significantly lower due to reduced lifetime. Additionally the GHG impact of nuclearand wind isn't quite proportional to energy payback time because of concrete. https://ieeexplore.ieee.org/document/8118077 https://ieeexplore.ieee.org/document/8118077 https://www.sciencedirect.com/science/article/pii/S0301421513003856 https://www.sciencedirect.com/science/article/pii/S030142151... Really though the answer is both are fine and nuclear probably wins once you include a mix of wind, hydro and storage. And embodied emissions will go down as low carbon energy becomes a bigger share. The main arguments against new nuclear are political (making new oil barons but with nuclear is stupid among other problems) and opportunity cost (using a nuclear reactor to replace 1GW of fossil fuels 80% of the time uses the same resources as using renewables to replace 10GW of fossil fuels ~40% of the time -- some of which is uncorrelated -- but at much longer delay).
himinlomax 4y ago
Several orders of magnitude over, yes.
deleted 4y ago
[deleted]
Schroedingersat 4y ago
This is loosely measured by EROI (energy return on invested). Concrete muddies the water slightly as it's a non-energy ghg emitter. The answer is definitely to the first part. By what ratio depends on who you ask. The nuclear lobby claims 50-80x. Most other people say it's in the 10-20x range. This is about as good as to somewhat better than wind, but at some point between 2012 and 2030 solar has surpassed/is going to surpass it by whichever measure you choose. Of course once the steel/silicon/composite/etc comes from low carbon sources, then the embodied carbon reduces as well. To the second part (while being profitable), no new nuclear build can be profitable, so no.

cinntaile 4y ago

Over their 40+ years lifetime it becomes negligible.

pasabagi 4y ago
Maybe? Because climate change is a self-feeding cycle, releasing large amounts of CO2 early, then amortizing that over decades of operation, is worse than a constant steady release. I guess you're probably right, nonetheless. It just annoys me when people post polls like this to prove that people in general are stupid, when polls generally show that ordinary people everywhere are way better on climate issues than political elites.
- petre 4y ago
  Concrete absorbs CO2 as it cures. If you add a bit of titanium dioxide it doubles the amount of absorbed CO2.

sanp 4y ago

But that’s sunk cost. That’s not increasing with consumption unless u get to a point where u have to build a new plant.

credit_guy 4y ago

This is incorrect. A large nuclear power plant uses about 200000 cubic meters of concrete. Each m3 of concrete contributes about half a ton of CO2 emissions, so that’s a one time 0.1 MT of CO2 emissions. A coal power plant of similar size will emit more than 1 MT every - single - year. There is simply no comparison.