At a minimum definitive must mean from today and until we can and will make any radioactive waste not radioactive waste anymore. If that requires safety against

At a minimum definitive must mean from today and until we can and will make any radioactive waste not radioactive waste anymore. If that requires safety against stone age explores or not I can't say. History has an abundance of tales of how we store things safe enough and then decades (or a few years) later we learn that dumping thousands of barrels of radioactive waste in the ocean was stupid, that slapping some concrete on top of a nuclear bomb test site didn't really contain it, that mixing chemical waste with earth and letting it sit near a river was pretty stupid, etc. etc. Definitive means it is 100% certain this is not happening with any radioactive waste as there's no lower limit where radiation isn't dangerous. "Definitely safe against human stupidity and error" seems fine to me for radioactive waste when there's zero need to produce any. Again, is that timescale up until stone age man in the future? I can't say but the producers of radioactive waste need to know the answer before they can built a storage facility or they'll have to make it safe enough for anything less than the earth going pooof.