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Comment by paulsutter | Hacker News Reader

Fusion will be practical long before the problems of fission are solved. Obviously photovoltaic is amazing and batteries are on a beautiful cost curve to help us with storage and there's alway pumped water, etc

But fusion will take us to the stars, and depending on how small it can be, may help in lots of other applications

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Fission will be practical (now) long before the problems of fusion are solved (maybe never).

Fusion has fission's biggest problem, which is the creation of large amounts of low-grade nuclear waste in the form of activated, radiation weakened reactor parts.

That doesn’t seem to be fission’s biggest problem.

Some of the more whackadoodle fusion plant designs (which nonetheless have millions in funding and early prototypes built) get around this by doing the fusion in a blanket of liquid metal, or by using aneutronic fusion (which requires ridiculously high temperatures), or by using the neutron activation to breed more fuel.

That isn't remotely close to fusion's biggest challenge. If you can generate 1 GWe for 30 years and deal with a small warehouse of low level waste for a few decades that is a nothingburger.

The biggest challenges to fusion is making a reactor quickly, cheaply, and with reasonable uptime / maintenance.

Don't forget making it safely. It's fairly easy to make something safe it everything goes perfectly. Making it safe in the context of human failings is a whole different thing.

Are we mixing up fusion and fission here? Fission has cost problems. Fusion doesn't have cost problems, it has viability problems. We still haven't even produced net positive energy. Then, if that milestone is reached, continuous production is going to be an engineering challenge. I'm optimistic that humanity will be able to get it working given enough time, but it's not a solution to any energy problem right now or the near or even middle future.

I don't see the difference between cost and viability. Of course we can fuse atoms. We've been doing it with regularity since the 50s. Of course we can use magnetic confinement to do it. The only reason we haven't burned a plasma in a magnetic confinement machine is because the machine to do it costs a lot of money. We don't have the industrial throughput as a society to make 1,000 megaprojects simultaneously. Whether you call that a cost problem or a viability problem is irrelevant.

Fusion's biggest problem is that the Sierra Club and other similar environmentalist groups hate it.

No silver bullet technology can fix that.

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