I've heard the label “clean” used for nuclear energy, often in the context of greenhouse gas emissions. It's one of the lowest emitters of greenhouse gases of all of our possible energy sources. That is not to say there aren't any other issues with it, but as far as the nuclear waste goes, from what I understand we have the expertise and capability of handling those materials over the long term.
As far as I know, the nuclear industry's safety record, as far as losses of life and accidents go, is actually one of the lowest of all energy industries in Canada.