4 ms·

The uranium cycle requires heavy equipment (dozers, loaders, trains, trucks, etc), all of which run on fossil fuels, so it's not "carbon free."

theamk 7y ago
It is not fully carbon free, yes; but compared to fossil fuels, it practically is.
roenxi 7y ago
Breathing produces carbon dioxide; so you aren't going to get very far with that sort of argument. Nothing is carbon free. The heavy equipment is not going to produce enough carbon to be worth measuring on a per kW basis. The energy density of nuclear fuel is just too high.
acidburnNSA 7y ago
That's included in the number of 11 gCO2-eq/kWh. Please refer to this comment where you were lightly reprimanded for saying that. https://news.ycombinator.com/item?id=19905223 https://news.ycombinator.com/item?id=19905223 I say carbon-free for anything that's under 40 gCO2-eq/kWh (so I can include solar), which is 10x less than natural gas, 20x less than coal. Nuclear is 40x less natural gas! It's the lowest carbon energy source we know, tied with wind.
- mimixco 7y ago
  Thanks but you've said elsewhere that you work in the nuclear industry. HN is not a place where we need to "reprimand" each other.
  - acidburnNSA 7y ago
    We do need to provide meaningful feedback to things that are incorrect, such as the suggestion that nuclear is not tied with wind as the lowest-carbon full-lifecycle energy source we know. I chose to work in the nuclear industry specifically to help avert climate change. I was like: "I want to help reduce climate change. Aha, nuclear is interesting because it's low-carbon and also not perfected. That's a good challenging problem to work on!" This doesn't invalidate anything I've said. In fact, it bolsters things I say because it means I know what I'm talking about.
    - mimixco 7y ago
      That's fine and you're free to do that, but it doesn't make what I said "incorrect." The uranium cycle uses carbon and, what's worse, produces vast amount of tailings (radioactive waste) which contaminate land and water. This is in addition to the spent fuel rods which most people think of as "nuclear waste." I hope that you could agree that those are true statements.
      - DuskStar 7y ago
        By that standard, there are no carbon-free energy sources.
        mimixco 7y ago
        So people should stop claiming that nuclear is one. It's an advertising term used by the industry, nothing more.
        acidburnNSA 7y ago
        Nuclear fission is neutron + uranium = fission products and energy. This process is literally carbon-free. Solar PV is photons + semiconductors = electric current. This is directly carbon-free. Wind is wind + blades = mechanical motion. This is directly carbon-free. Coal, natural gas, oil, and biomass are Carbon + heat in the presence of oxygen is CO2 + energy. These are not carbon-free. This is the purpose of the term carbon-free. Now, literally everything has non-zero carbon lifecycle costs as long as we are using carbon-derived energy in our infrastructure. It is impossible to be fully carbon-free with coal, natural gas, oil even if all your infrastructure is electric. With solar, nuclear, wind, etc., you can get to a truly carbon-free lifecycle if you work hard to electrify or otherwise clean up your trucks. Meanwhile, today, nuclear lifecycle is the most carbon-free overall, tied with wind. The term carbon-free is used colloquially to mean anything that doesn't directly make carbon alongside energy. It is right and proper to point out lifecycle carbon costs too, and again nuclear is tied for lowest lifecycle. Nuclear is the most carbon-free thing we have. You bet it is advertising. It's truthful advertising of the positive characteristics of nuclear energy. People have a right to know how carbon free various energy sources are.

theamk 7y ago

It is not fully carbon free, yes; but compared to fossil fuels, it practically is.

roenxi 7y ago

Breathing produces carbon dioxide; so you aren't going to get very far with that sort of argument. Nothing is carbon free. The heavy equipment is not going to produce enough carbon to be worth measuring on a per kW basis. The energy density of nuclear fuel is just too high.

acidburnNSA 7y ago

That's included in the number of 11 gCO2-eq/kWh. Please refer to this comment where you were lightly reprimanded for saying that. https://news.ycombinator.com/item?id=19905223 https://news.ycombinator.com/item?id=19905223 I say carbon-free for anything that's under 40 gCO2-eq/kWh (so I can include solar), which is 10x less than natural gas, 20x less than coal. Nuclear is 40x less natural gas! It's the lowest carbon energy source we know, tied with wind.

mimixco 7y ago
Thanks but you've said elsewhere that you work in the nuclear industry. HN is not a place where we need to "reprimand" each other.
- acidburnNSA 7y ago
  We do need to provide meaningful feedback to things that are incorrect, such as the suggestion that nuclear is not tied with wind as the lowest-carbon full-lifecycle energy source we know. I chose to work in the nuclear industry specifically to help avert climate change. I was like: "I want to help reduce climate change. Aha, nuclear is interesting because it's low-carbon and also not perfected. That's a good challenging problem to work on!" This doesn't invalidate anything I've said. In fact, it bolsters things I say because it means I know what I'm talking about.
  - mimixco 7y ago
    That's fine and you're free to do that, but it doesn't make what I said "incorrect." The uranium cycle uses carbon and, what's worse, produces vast amount of tailings (radioactive waste) which contaminate land and water. This is in addition to the spent fuel rods which most people think of as "nuclear waste." I hope that you could agree that those are true statements.
    - DuskStar 7y ago
      By that standard, there are no carbon-free energy sources.
      - mimixco 7y ago
        So people should stop claiming that nuclear is one. It's an advertising term used by the industry, nothing more.
        acidburnNSA 7y ago
        Nuclear fission is neutron + uranium = fission products and energy. This process is literally carbon-free. Solar PV is photons + semiconductors = electric current. This is directly carbon-free. Wind is wind + blades = mechanical motion. This is directly carbon-free. Coal, natural gas, oil, and biomass are Carbon + heat in the presence of oxygen is CO2 + energy. These are not carbon-free. This is the purpose of the term carbon-free. Now, literally everything has non-zero carbon lifecycle costs as long as we are using carbon-derived energy in our infrastructure. It is impossible to be fully carbon-free with coal, natural gas, oil even if all your infrastructure is electric. With solar, nuclear, wind, etc., you can get to a truly carbon-free lifecycle if you work hard to electrify or otherwise clean up your trucks. Meanwhile, today, nuclear lifecycle is the most carbon-free overall, tied with wind. The term carbon-free is used colloquially to mean anything that doesn't directly make carbon alongside energy. It is right and proper to point out lifecycle carbon costs too, and again nuclear is tied for lowest lifecycle. Nuclear is the most carbon-free thing we have. You bet it is advertising. It's truthful advertising of the positive characteristics of nuclear energy. People have a right to know how carbon free various energy sources are.