Maybe this is a dumb question but couldn't we ship the waste to another planet (of course once we have rockets capable of doing so but that's not far imo).
We could fly it into the sun, the problem is that until we have a space elevator the only way we have of getting it out of the atmosphere is via rockets and a rocket explosion with a nuclear waste payload would be very bad.
We can just bury it in a cement casket.
There isn't that much of it once it is solidified and it isn't that dangerous.