3 ms·

"Along with the new, more efficient steam generators..." How much more efficient? Side note: why isn't super-critical CO2 (ScCO2) turbine technology in use on

by mikece 4y ago

"Along with the new, more efficient steam generators..." How much more efficient? Side note: why isn't super-critical CO2 (ScCO2) turbine technology in use on commercial-grade projects? I realize nukes don't make enough head for ScCO2 but coal and natgas plants do, and efficiencies in converting thermal energy to electric are around 45% as opposed to 33% for the best steam turbines.

opwieurposiu 4y ago
The old SG's were 1.5% plugged, so efficiency was only down a bit. The real issue is that some Westinghouse Steam Generators have issues with unexpected vibrations that wear holes in the tubes. https://www.nrc.gov/docs/ML2113/ML21130A040.pdf https://www.nrc.gov/docs/ML2113/ML21130A040.pdf https://www.nrc.gov/reading-rm/doc-collections/gen-comm/bulletins/1988/bl88002.html https://www.nrc.gov/reading-rm/doc-collections/gen-comm/bull...
PaulHoule 4y ago
In the case of natural gas you can already use an internal combustion gas turbine. People have been talking about doing the same with coal since the 1970s https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle https://en.wikipedia.org/wiki/Integrated_gasification_combin... but it has seen very little traction. In principle you could capture CO₂ pre-combustion but the capital cost is high and the plants that have been built have performed terribly. Cheap natural gas has crowded out other energy technologies in the US and Europe, in other places utilities can just pass costs onto the consumers so why take a chance on anything that's risky to develop? Those ScCO₂ turbines or something similar are required if new nuclear is going to be competitive with natural gas, never mind with solar and wind, but the technology is not a bird in the hand. Even if people could build new nuclear plants on schedule they are still too expensive because of the cost of the steam turbine plus the cost of those very large steam generators which have to be inside the confinement structure. From 1950 until most countries gave up on fast reactors the argument for fast reactors was much better (60x better!) efficiency of using uranium, but the argument for fast reactors today is if you get rid of the water you can run much hotter and use a gas turbine but there is a ways to go to get there. There's also the possibility of high temperature thermal reactors using graphite but graphite has its own problems, mostly it crumbles when exposed to neutrons also it seems to cause corrosion problems in many environments. Fast reactors w/ gas turbines look like they could hold their own against natural gas, solar and wind even in the currently fashionable accounting where solar and wind don't get dinged for only supplying energy when they want to.

by mikece 4y ago

opwieurposiu 4y ago

The old SG's were 1.5% plugged, so efficiency was only down a bit. The real issue is that some Westinghouse Steam Generators have issues with unexpected vibrations that wear holes in the tubes. https://www.nrc.gov/docs/ML2113/ML21130A040.pdf https://www.nrc.gov/docs/ML2113/ML21130A040.pdf https://www.nrc.gov/reading-rm/doc-collections/gen-comm/bulletins/1988/bl88002.html https://www.nrc.gov/reading-rm/doc-collections/gen-comm/bull...

PaulHoule 4y ago

In the case of natural gas you can already use an internal combustion gas turbine. People have been talking about doing the same with coal since the 1970s https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle https://en.wikipedia.org/wiki/Integrated_gasification_combin... but it has seen very little traction. In principle you could capture CO₂ pre-combustion but the capital cost is high and the plants that have been built have performed terribly. Cheap natural gas has crowded out other energy technologies in the US and Europe, in other places utilities can just pass costs onto the consumers so why take a chance on anything that's risky to develop? Those ScCO₂ turbines or something similar are required if new nuclear is going to be competitive with natural gas, never mind with solar and wind, but the technology is not a bird in the hand. Even if people could build new nuclear plants on schedule they are still too expensive because of the cost of the steam turbine plus the cost of those very large steam generators which have to be inside the confinement structure. From 1950 until most countries gave up on fast reactors the argument for fast reactors was much better (60x better!) efficiency of using uranium, but the argument for fast reactors today is if you get rid of the water you can run much hotter and use a gas turbine but there is a ways to go to get there. There's also the possibility of high temperature thermal reactors using graphite but graphite has its own problems, mostly it crumbles when exposed to neutrons also it seems to cause corrosion problems in many environments. Fast reactors w/ gas turbines look like they could hold their own against natural gas, solar and wind even in the currently fashionable accounting where solar and wind don't get dinged for only supplying energy when they want to.