The fuel production does not deal with heavy metal mining and then processing. The reactor itself is save in the sense that the worst thing that can happen is,

The fuel production does not deal with heavy metal mining and then processing. The reactor itself is save in the sense that the worst thing that can happen is, that you scorch the reactor wall, because there is just not enough energy in the reactor at any given time. And if there is something going wrong then you're dealing with a nuclear inventory of a few grams hydrogen that will quickly oxidize into heavy water, instead of a thousand tonnes of fuel that will happily melt under its own few hundred megawatts of decay heat. And the end product of the fusion reaction is helium, which is chemically inert and not radioactive. Instead most of the radioactive waste are the reactor walls, which are activated iron and therefore have a half live of 2.5 yrs, so you have to keep the radioactive waste for something like 250 years save instead of for 250 000 years, and it is iron, not a complex mix of heavy metals and gases that over time changes it's composition. [PS:] Forgot the proliferation aspect. There is actually not that much difference between a civilian and military nuclear program. By contrast the main proliferation problem of fusion is, that it deals with a lot of tritium and it is straightforward to build a tritium booster for a bomb, however for that you need a bomb first.