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Nuclear fusion is close enough to start dreaming

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Re: Nuclear fusion is close enough to start dreaming

#11

Post by ericd »

7373737373 wrote: post #9
deegles wrote: post #4

Think of all the fusion powered direct air CO2 capture we could have <3

I wonder how many capture plants and energy would be required to bring it back to a normal level.

Let's run the numbers. I believe Climeworks' Orca is the largest DAC plant right now, and they claim it'll capture 4000 tons/year. We currently emit something like 40 gigatons/yr. (4*10^10)/(4*10^3) = 10^7 DAC plants. So let's say that DAC isn't a silver bullet :-) There are a whole portfolio of other carbon capture and sequestration technologies that'll be needed to get us carbon-negative enough to avoid going over +2 degrees C.

Of course, by the time we have spare fusion power, that'll also have replaced much of those 40 gigatons, and Orca is certainly not the upper limit in terms of scale.

Re: Nuclear fusion is close enough to start dreaming

#12

Post by Animats »

benreesman wrote: post #7

I’m an interested layperson at best, but I gather that we know how to build safe fission reactors now, and that the safe storage of spent (or “slightly used” as I’ve heard it called) fuel pellets is a much harder political problem than technical problem. Gorbachev once speculated that it was actually Chernobyl that brought down the USSR. I personally wonder if it’s also why we’re going to have a climate catastrophe.

I gather that we know how to build safe fission reactors now.

One can hope. "Gen III" fission reactor construction is coming along, mostly in China. Sanmen Nuclear Power Station has two Gen III reactors, designed by what's left of Westinghouse. Future versions are being entirely designed in China.

Most of the "small cheap reactor" concepts are arguments for why they don't need a containment vessel. That's probably not going to sell. Chernobyl wasn't supposed to need a containment vessel, and didn't have one. Fukushima didn't have a big enough one. Three Mile Island did have a good containment, which is why that meltdown was expensive, but didn't cause much trouble outside the plant.

Re: Nuclear fusion is close enough to start dreaming

#13

Post by gus_massa »

deegles wrote: post #4

Think of all the fusion powered direct air CO2 capture we could have <3

When you find yourself in a hole, stop digging.

The first landmark is to make coal plants unprofitable. Once all (most of) the coal and oil plants are closed, it would be interesting to use the spare electricity for carbon capture. Otherwise you are burning coal to power the carbon capture facility.

Re: Nuclear fusion is close enough to start dreaming

#15

Post by Animats »

benreesman wrote: post #7

I’m an interested layperson at best, but I gather that we know how to build safe fission reactors now, and that the safe storage of spent (or “slightly used” as I’ve heard it called) fuel pellets is a much harder political problem than technical problem. Gorbachev once speculated that it was actually Chernobyl that brought down the USSR. I personally wonder if it’s also why we’re going to have a climate catastrophe.

What to do with spent fuel rods is more of a political problem than a technical one. Read up on Yucca Mountain.

Current thinking is that the best approach to long term disposal is to find a cold hard-rock mountain where nothing has changed much in millions of years. Dig tunnels that are far above any possible flooding. Drill vertical holes in the tunnels. Package the nuclear waste in stainless steel thimbles, with the waste embedded in ceramic. Place thimbles in holes. After a few decades of nothing happening, fill in the tunnels.

Sweden and Finland, which have lots of stable, isolated hard rock mountains, are working on this. So is China, which now has two vitrification plants for nuclear waste.

Re: Nuclear fusion is close enough to start dreaming

#16

Post by civilized »

gus_massa wrote: post #13
deegles wrote: post #4

Think of all the fusion powered direct air CO2 capture we could have <3

When you find yourself in a hole, stop digging. The first landmark is to make coal plants unprofitable. Once all (most of) the coal and oil plants are closed, it would be interesting to use the spare electricity for carbon capture. Otherwise you are burning coal to power the carbon capture facility.

I don't know, we might need technology to save us from our seemingly bottomless stupidity. Maybe in 2050, Robo-Joe Manchin will secure a permanent government slush fund for Greater West Virginia coal mining and we'll have to stick a fusion-powered CO2 capture facility right next to where they burn it.

Re: Nuclear fusion is close enough to start dreaming

#17

Post by dwheeler »

platz wrote: post #3

> The nuclear fusion startup Helion, which announced last week that it has raised $500 million, says it has developed new technologies that may make nuclear fusion viable — practically, economically and environmentally. This is the only actual news in the article. The rest is bog-standard speculation.

"May" is pretty specious. Is there any evidence of something likely to work? I would love to see practical fusion, but I see no reason to believe it will exist soon. Someone has to figure out how to actually make it practical first.

Re: Nuclear fusion is close enough to start dreaming

#20

Post by bluecalm »

Animats wrote: post #15
benreesman wrote: post #7

I’m an interested layperson at best, but I gather that we know how to build safe fission reactors now, and that the safe storage of spent (or “slightly used” as I’ve heard it called) fuel pellets is a much harder political problem than technical problem. Gorbachev once speculated that it was actually Chernobyl that brought down the USSR. I personally wonder if it’s also why we’re going to have a climate catastrophe.

What to do with spent fuel rods is more of a political problem than a technical one. Read up on Yucca Mountain. Current thinking is that the best approach to long term disposal is to find a cold hard-rock mountain where nothing has changed much in millions of years. Dig tunnels that are far above any possible flooding. Drill vertical holes in the tunnels. Package the nuclear waste in stainless steel thimbles, with th…

First question I have about it: wouldn't it be an attractive target for bombing/terrorist attacks or would it be rock solid enough to withstand those?
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