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243 points greesil | 1 comments | | HN request time: 0s | source
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sheepscreek ◴[] No.44637662[source]
TL;DR - Looks dangerous, but is it? (open question) Can we quantify it or at least make it more tangible?

God, this contraption appears to be the kind of thing I wouldn’t trust my life with. Every time I look at a fusion reactor, it seems far more dangerous than my hobby lab, failing to inspire any confidence. The numerous moving parts create an equal number of potential points of failure. In contrast, a nuclear reactor doesn’t have to contend with plasma gases hotter than the Sun, contained within an artificial bubble solely through the assistance of electromagnetic radiation.

I’ve often tried to imagine the worst case scenario, but I am limited by my knowledge on the subject. What kind of damage can hot plasma at a few million degree C do?

On one hand, the plasma is hotter than anything on earth created by mankind. Then I believe there’s also a significant number of wild neutrons shooting around which can cause havoc in their own right, if not contained. But on the other hand, unlike an uncontrolled chain reaction, without a source of heat, the whole operation shuts off by itself. I’m probably wrong about a few assumptions here but this is what I often find myself wondering.

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thinkcontext ◴[] No.44639967[source]
That fusion reactions are so difficult to get started makes the reactors very safe because failure makes them stop. So, if you lose magnetic confinement the reaction stops. The reactor may be damaged but that's it.

This is unlike fission reactors, where a failure causes reactivity to increase. That causes meltdown and the possibility of explosion and all the nasty radioactive contamination.

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1. mathw ◴[] No.44644925[source]
My understanding is that more recent fission reactor designs are done in such a way that they fail in ways which cause the reaction to diminish rather than build up further, which puts you in a better place than, say, Chernobyl.

You still have a very hot very radioactive lump of death in the middle of your busted reactor when it's all done though, and that's definitely not fun. Fusion failure modes - in current designs anyway - are far more appealing to anybody who happens to be in the area at the time.