It’s pretty solved. There is very little of the dangerous stuff, and it is far less dangerous after a few decades. It can safely sit in casks for more than a thousand years. At which point there’s a negligible amount of anything really nasty left. At any point we can basically just stick it all in a salt mine and call it a day.

Future people will be fine. Shit we discovered uranium because some guys wandered into a cave and it burned their skin. Locals avoided it afterwards and eventually it was studied by people who knew what radiation was. Any actual storage though would be deep underground, in casks, and behind concrete with lots of warning signs.