4 ms·

> "I would not permit construction of a plant that could, by design, be a danger to anything other than itself if it lost power." What about a plant that's a d

> "I would not permit construction of a plant that could, by design, be a danger to anything other than itself if it lost power." What about a plant that's a danger to others when it's running optimally within design spec, as every single coal fired plant on this planet is? Do you apply this standard to all power plants, or only nuclear?

amluto 7y ago
I think that, even in an appropriately regulated and taxed environment, coal has a place. In particular, fly ash can replace a respectable fraction of the cement used in concrete. If a coal-fired power plant can scrub its emissions to remove particulates and CO2, it may be cost effective as a source of fly ash compared to the (taxed) cost of cement production. I'm skeptical that "clean coal" will ever be cost-effective when considered purely as a source of power in most locations.
- darkpuma 7y ago
  As far as I'm aware coal (particularly coke) plays a vital role in the production of steel, so I don't expect we'll do away with it anytime soon. But it's very frustrating to see coal being given a free pass by critics of nuclear, particularly when those critics call themselves environmentalists.
  - pfdietz 7y ago
    One can make steel without using coal or coke. Some steel is made this way even today ("Direct Reduced Iron", particularly the mode where iron ore is reduced with syngas made with natural gas). Hydrogen could be used instead of syngas to do this reduction, and the amount of carbon that would be needed to make the final alloy would be small, and could be sourced from non-fossil sources.
- robocat 7y ago
  > coal has a place [snip] in particular, fly ash can replace a respectable fraction of the cement used in concrete. AFAIK fly ash is mostly used as a replacement for other filler (sand etc)... Using fly ash doesn't change the amount of CO2 produced per m3 of concrete. I am struggling to understand what your point is here. Also fly ash is generally a single digit percentage by coal weight burnt. So say 90% of coal burns with oxygen, most of which ends up as CO2 (by weight). Using the fly ash waste (from electricity generation) in concrete makes sense. Burning coal to indirectly justify making cement does not.
  - amluto 7y ago
    As I understand it, fly ash can replace a fair amount of the cement, and cement production is CO2-intensive.
    - darkpuma 7y ago
      Your understanding is correct, fly ash can be used as a substitute for portland cement. It's apparently chemically similar to how the Romans used to use volcanic ash in their concrete mixes. A lot of cement sold these days is a mixture of fly ash and portland cement. My impression is that fly ash involves the production of more CO2 than burning coal to produce an equivalent amount of portland cement, but it's worth it when you're burning coal anyway and fly ash is basically free as a byproduct. So in practice it essentially offsets CO2 emissions from burning coal, but only partially. That's just the impression I've gotten though, I don't have any numbers for any of it.

amluto 7y ago

I think that, even in an appropriately regulated and taxed environment, coal has a place. In particular, fly ash can replace a respectable fraction of the cement used in concrete. If a coal-fired power plant can scrub its emissions to remove particulates and CO2, it may be cost effective as a source of fly ash compared to the (taxed) cost of cement production. I'm skeptical that "clean coal" will ever be cost-effective when considered purely as a source of power in most locations.

darkpuma 7y ago
As far as I'm aware coal (particularly coke) plays a vital role in the production of steel, so I don't expect we'll do away with it anytime soon. But it's very frustrating to see coal being given a free pass by critics of nuclear, particularly when those critics call themselves environmentalists.
- pfdietz 7y ago
  One can make steel without using coal or coke. Some steel is made this way even today ("Direct Reduced Iron", particularly the mode where iron ore is reduced with syngas made with natural gas). Hydrogen could be used instead of syngas to do this reduction, and the amount of carbon that would be needed to make the final alloy would be small, and could be sourced from non-fossil sources.
robocat 7y ago
> coal has a place [snip] in particular, fly ash can replace a respectable fraction of the cement used in concrete. AFAIK fly ash is mostly used as a replacement for other filler (sand etc)... Using fly ash doesn't change the amount of CO2 produced per m3 of concrete. I am struggling to understand what your point is here. Also fly ash is generally a single digit percentage by coal weight burnt. So say 90% of coal burns with oxygen, most of which ends up as CO2 (by weight). Using the fly ash waste (from electricity generation) in concrete makes sense. Burning coal to indirectly justify making cement does not.
- amluto 7y ago
  As I understand it, fly ash can replace a fair amount of the cement, and cement production is CO2-intensive.
  - darkpuma 7y ago
    Your understanding is correct, fly ash can be used as a substitute for portland cement. It's apparently chemically similar to how the Romans used to use volcanic ash in their concrete mixes. A lot of cement sold these days is a mixture of fly ash and portland cement. My impression is that fly ash involves the production of more CO2 than burning coal to produce an equivalent amount of portland cement, but it's worth it when you're burning coal anyway and fly ash is basically free as a byproduct. So in practice it essentially offsets CO2 emissions from burning coal, but only partially. That's just the impression I've gotten though, I don't have any numbers for any of it.