this post was submitted on 01 Dec 2023
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@throws_lemy
fukoshima 2 electric bugaloo
I’m as much a nuclear skeptic as anyone, but while fusion solves neither the time or budget problems of fission, it does solve the meltdown and waste problems.
The reaction used in fusion generators is:
[2]H + [3]H -> [4]He + n
Since tritium is usually produced from lithium in situ, you add:
[6]Li + n -> [3]H + [4]He.
The only radioactive thing here is tritium, and it's mostly confined to the reactor. Also, tritium isn't nearly as bad as fission waste.
So does this also mean that glow-in-the-dark watches (the non electronic type) get cheaper?
I mean, if you could extract any tritium from the reactor cavity, but it's probably going to get burned up instantly.
The reactions I showed add up to this overall reaction. Neutrons simply serve as a catalyst.
[2]H + [6]Li -> 2 [4]He
On the bright side, fusion reactors produce helium as a byproduct, which might make party balloons cheaper.
It improves the waste issue, doesn't really solve it. A dirty, little-discussed secret about fusion power.
If we had a bunch of fusion plants go live, we'd soon have tons and tons of radioactive containment wall material to bury/store somewhere. Including all the special handling requirements that you need with fuel rod waste. I think fusion plants would actually create more waste than a comparable fission plant, at least as far as tons of radioactive material.
The benefit is that waste would be lighter isotopes and degrade faster. So you have more physical material to worry about but only need to worry about it for ~100 years, not thousands.
Still far better than thousands of tons of toxic and radioactive fly ash from coal.
The decommissioning plans for ITER more or less literally say "let stand there as-is for 100 years, then demolish as usual". Fisson plants, which don't use less concrete, need to be taken apart small section by small section, each single piece analysed for radiation and sorted into long- or short-term storage. Fusion plants are only marginally more of a headache safety-wise than the radiology department of a hospital and you don't generally hear people complaining about those.
So does 4 other fission power plants we can imagine. Now sure why we’re so Darwindamned fixated on fusion - I suspect it’s just the name.
Fissionable isotopes are yet another nonrenewable fuel.
Hydrogen is the most abundant element in the universe.
With reprocessing, which we already do, and new Gen IV power plants, there’s enough energy to last us thousand of years with currently known resources. And that’s before we start scooping it out of the water.
That's assuming a lot of ifs resolve our way, and without power needs increasing. It's more sustainable than coal/gas/oil for sure, but with current energy development needs it's barely long term (IIRC about 60-140 years)
Also, on centuries timescale, we will need to find more fissiles in space. And according to our current understanding of the universe, they should be quite rare, especially compared to hydrogen.
Basically, figuring out fusion power would solve our needs for the first level on the Kardashev scale, and has the potential to be portable fuel for the rest of the lifespan of the universe.
My aim is not to stop research on fusion - just making the point that we know how to do nuclear and it seems to me we are letting perfect be the enemy of good.
Oh, we need both for sure, and renewables as well.
Then we are in remarkable agreement. Nuclear, fusion and TONNES of renewables. The quicker, the better.