Problem is that there is currently no actual place to put the stuff so it’s not localized. If a war broke out or a serious terror campaign, the first thing to be targeted would be the locations of power infrastructure and this waste. Not to mention natural disasters or them just being ignored for too long like global warming has been. In a few decades the amount could easily double or more. There’s plenty of it that if it were to reach a major river or other waterway it could spread significantly.

My point is, why risk it when this technology doesn’t even produce as much energy as we could produce with renewables with comparatively little risk of pollution? The only reason it looks good on paper is that no company expects to exist long enough to care about the waste, so no money is set aside to deal with it. Just like no money is set aside to deal with climate change. And even if it was set aside to deal with the current waste by pitting it in long term storage. That storage isn’t long-term enough to actually keep it until it’s safe. Sure it will be safe for a long time, but eventually it will leak and if no one knows it’s there or the tech to deal with it isn’t there by then, it will spread and if will spread far and wide over the hundreds of thousands of years it has to spread. And sure the US is landlocked and may find a place that the tectonic plates never split the continent. But in a million years it’s unlikely that Europe will look the same do it’s likely the Atlantic will get contamination and Japan is a volcanic island so it’s pretty likely it will leak into the Pacific. I’m saying there’s enough in existence already for the majority of the world to get contaminated. And if life hasn’t already been wiped out by climate change or war, it likely will face an existential threat from this. So why use it if there are alternatives that are really not that much more expensive to construct? It’s only because those are less expensive to maintain and thus less opportunity for extracting profit from those services.