Undoubtedly myths and stories contain information but I don't think they really work to pass on history or science - otherwise they would be known as history and science rather than myths.
Suspect they stop working around the same point as they are codified as religions - at the point when people forget their meaning.
Best for nuclear waste is to not create it, probably not possible to guarantee that waste already stored will always be identifiable in the event of the collapse of civilisation. Though seems quite likely that by that point large areas of Earth could be radioactive anyway.
Foward Hari Seldon!