It would never fly politically, but we could effectively deal with nuclear waste in a future-proof way if we dissolved it into sea water. Uranium's natural concentration in sea water is 3 parts per billion and there are 1.3e21 kilograms of sea water. This comes out to 3.9e9 metric tons of uranium already in sea water; all these numbers utterly dwarf all the nuclear waste we could possibly ever create. Even when you consider that natural uranium is merely a toxic heavy metal and high grade radioactive waste is substantially more radioactive, that doesn't change much. The intensity of radioactive waste drops substantially if you store it even for just a few decades, which is probably unnecessary but certainly manageable.

I don't seriously propose this though, it would be pointless to propose because it would never be accepted. Even Japan dumping a tiny bit of tritium into the ocean has turned into a big controversy. Seriously suggest something like the above and most people will think you're an insane troll.