3 ms·

There is one such site in Finland: https://en.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_repository https://en.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_re

• gambiting 7y ago
  That's not quite the same - it's more like a mine than a borehole. The whole idea of a borehole is that stuff sealed 5km under the surface isn't coming back in any way, and is nearly impossible to recover unless you drill another borehole in the same place. There is no known geological process that would bring it back up naturally. The site you quoted is pretty deep(500m) but it's not "stable and permanent for millennia" kind of deep.