I really like the argument of just keeping the waste on site at the reactors. They're already heavily guarded and everybody is trained to deal with the waste + safety inspections happen regularly.

Just keep the waste on site and then, if a plant is decommissioned, add it to another reactor's pile.

It's not a permanent solution for millions of years, but it's also likely fine for the next 100 years and that's a reasonable tradeoff (imo).