A lot has been written on it, and we've been told by many reputable people that it's not a big problem. If climate change really is a dire threat, nuclear waste is just a non-issue relatively speaking. Anyone promoting that we should block nuclear because of waste is some kind of bad faith actor.
I think not a bad faith actor, but an emotionally dominated actor. Most of the anti-nuclear opposition is about gut level emotion. This is why the bar is raised so much higher for nuclear than anything else. The reason boils down to "but this is nuclear!!
Indeed, I have thought about this "deeply". But not hysterically, which is why you seem to be so troubled about a calm assessment of risk that takes into account other risks we already accept and things like opportunity costs.
FWIW, there's nothing super-unique about the Finnish solution. Most countries have suitable geology. AFAICS, the main reason for the success of the project is that various hysterical anti-nuclear activists weren't allowed to dominate the discussion.
