You're going to run straight into 'NIMBY' and other political constraints for your eventually designated storage sites. I'm sure someone will find a way to argue that we should send it to the third world as long as we get to control the burial sites on account of proliferation worries. We've already done this with many other kinds of waste.

In the end it isn't about the area directly affected in the near future, it is about the long term effects and those are very hard to model accurately when it comes to massive deposits of nuclear waste.

Just a couple of the risks: massive terrorist target, risk of pooling, risk of large scale groundwater contamination, risk of the whole thing blowing up. These are not trivial and not all of them can be dealt with over the time-scales that the waste would still be significantly radio active.

Political structures are not stable across the time-scales that you are looking at here, you might end up seriously regretting any particular site a few hundred years into the future.