...and lithium. At least the current generation. While there's plenty of deuterium in the oceans (left over from the big bang, or at least that's the best theory we've got) tritium is a completely different matter: It's extremely rare because it's not stable with quite low half-life (12.32 years). If you throw a neutron at lithium though you get helium and tritium, and deuterium+tritium fusion happens to produce neutrons. All that btw yes is a bit radioactive the radiation safety requirements of a fusion reactor are ballpark those of the radiology department in your local hospital.

[–] DogWater@lemmy.world 1 points 7 months ago

Right, for the sake of brevity and not talking past my knowledge base, I was omitting that part. I knew that the deuterium reaction was coupled with tritium but I didn't know we had to use a precursor reaction to get the tritium. That's really neat knowledge.