The half-life isn't the relevant metric--you don't need the radioactivity to decay to zero (you're exposed to non-zero levels of radiation just walking around o

The half-life isn't the relevant metric--you don't need the radioactivity to decay to zero (you're exposed to non-zero levels of radiation just walking around outside). You need it decay to environmentally tolerable levels (roughly "the level of uranium ore"). Anyway, far more species are far more endangered by climate change right now than any future species will be by nuclear waste.