It’s the radioactive elephant in the room about nuclear energy — nuclear plants generate waste, and that waste is dangerous for tens of thousands of years, and what the hell do you do with it?
The answer to date from countries using nuclear plants is to stick it in metal drums in ponds (to cool it) and hope someone figures out a long-term solution before the drums rust through.
Finland is tired of waiting. It thinks it has a decent solution now that will serve for the extremely long period that the waste needs to be stored, and are proceeding with same. It’s not clear that the combination of geography, geology,, Finnish government, and community approval is transferable to other nations (these remain, in the US at least, an intractable problem), but I have to applaud them for taking action that sounds reasonable and makes as much sense as anything else proposed.
The World’s First Permanent Nuclear-Waste Repository
Buried deep under an island in the Baltic, the project is nearing completion. If all goes according to plan, future generations may not know it’s there.
Another, reasonably good, solution is burn-up reactors that are specifically designed to extract the remaining 99% of the energy from uranium that we currently are leaving sitting in metal drums in ponds, leaving us with waste that while vastly more radioactive is also waste that'll decay within/near one human life. Unfortunately, that's expensive, so instead we punt the problem to people living 10,000 years from now.