I am not a specialist but the current situation looks complicated and not because of waste disposal but for financial reasons and long term planning issues. Areva, the main civil nuclear actor, made a couple of very bad (and shady) decisions, lost a lot of money, and is currently being restructured and partially merged into EDF, the historical energy French provider. Still they decide to keep betting on EPR power plants and engage a lot of resources in a new Hinkley Point EPR project. None of which have been finished yet. At the same time, inquiries reveal deficiencies or falsifications on quality assesments on supplied parts. The gravity of these is not clear yet. Finally, budget are tightening and plants arriving to their initial end of life dates are being requalifed for a decade or more.

I do not think relying so much on nuclear energy was a bad move but it should have been a transitional thing (to renewable energy, fusion, anything else?). And it requires good forward thinking, commitment and the kind of leader we have not had for decades.

Finally, the EPR looks more and more like a big mistake. Smaller designs might have been more successful and offered more agility in time of crisis.

I think this is a reasonable way to view things. Although I think there is a lot of unexplored potential in fission. We're basically using tech developed in the 60s. And just a little nit pick: fusion is a form of nuclear power generation.

And who ensures that it stays there for the next centuries?

I doubt it would stay there for even the next few decades. As crazy as it sounds, I imagine at some point it would become cheap enough to launch into space or in to the sun. I mean, it wouldn't make economic sense. But at some point it would be worth the cost if only so that we don't have to listen to the irrational and ignorant braying of the so called 'green movement'.

They're like the kids in high school who decided they were avowed communists, except now all grown up.

Who says we won't figure out how to reprocess it and safely burn the fissile waste in the next centuries? :)

Geological objects of no worth to anyone tend to stay where they are for long, long, times.