I think my prof's main point was that the volume of waste could be problematic. If a fusion reactor had a 50-60 year life it could activate a lot of material.

I think my prof's main point was that the volume of waste could be problematic. If a fusion reactor had a 50-60 year life it could activate a lot of material. The volume of fission reactor waste is small enough to be stored on site (so far) for decades and reprocessing can reduce that dramatically.