How does nuclear fusion create radioactive waste?

Question

I just read in the Economist that nuclear fusion produces much less radioactive waste than nuclear fission. Now, I've always thought that nuclear fusion produces ZERO radioactive waste. Can anyone explain where this comes from?

Answer 1

The fusion process is very energetic. The vessel in which the fusion takes place will become radioactive due to the neutron flux. So although there is a lot less hazardous waste, there will be some.

Answer 2

The neutrons from most, but not all, fusion reaction release neutrons. Many, but not all, materials become radioactive when exposed to them. The trick, then, is to design a reactor around aneutronic reactions (hard), and/or use materials that don't activate (easier). There will always be some level of activation that must be tolerated, though, but it would be thousands of time less than a fission plant.