Yeah I've seen numerous links to that pointed to from HN over time. The problem with all of those proposals is that to an ignorant archeologist from, say, a hundred years ago, any visible sign, warning or construction will only pique the curiosity. I mean Tutankhamun's tomb had plenty of warnings inscribed on it, but they were dismissed as silly curses and there's no such thing as curses. The same will happen with nuclear storage sites that are 'protected' like that.

Better to put it away very deep, where erosion and tectonic shifts won't expose it for a million years and just forget about it. I read something about putting it in deep boreholes the other day.