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BlueSkyToday t1_j106ge8 wrote

Reply to comment by ItsAConspiracy in Nuclear fusion breakthrough: What does it mean for space exploration? by Gari_305

Yes, spent fuel rods are a lot more dangerous but the cost of mass to orbit is very high. Every plan that I've heard of calls minimizing the size of the reactor and the fuel load. So we're looking at highly enriched uranium or other possible designs. These are more of a problem than what we normally use in fission reactors.

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ItsAConspiracy t1_j10bji0 wrote

The half-life of U235 is 700 million years. The longer the half-life, the less radioactive something is, so even weapons-grade uranium at over 90% U235 is not particularly dangerous. You wouldn't want to eat it or inhale a large concentration of it, but you wouldn't want to do that with solid rocket fuel either.

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BlueSkyToday t1_j1p3ws0 wrote

In a world where people are deeply upset about the environmental health effects of fragments of shells made out depleted uranium, I don't think that scattering highly enriched uranium is going to fly.

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ItsAConspiracy t1_j1pzpeu wrote

And yet, plutonium-238 has flown multiple times, and that's way more radioactive.

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