This is true, all our warnings might only encourage people. Perhaps the best thing would be just to leave it unmarked, let the curious spelunkers die of radiation poisoning and that'll probably serve to keep more people out than building monoliths... or especially buried monoliths.
I mean burrying monoliths may only serve to get people to dig deep and reduce the natural shield we wanted to protect people from the radiological materials.
Burying them in a place where no one will go, meaning they'll have to have a more concerted effort to dig in say the middle of a salt flat. Meaning some level of organization and technology to dig 1,000ft deep in the middle of a dry salt water lake bed a hundred miles from drinkable water.
Many of the salt flats in the Western USA used to be great lakes as recently as a few thousand years ago. What is now "a dry salt water lake bed a hundred miles from drinkable water" could very well become abundant land in 10,000 years.
This is a really good point. Going back a mere 20,000 years there was an ice age, glaciers covered much of north america, and you could walk on land from China to Australia. Burying stuff with a half life of 25,000 years means that in 25,000 years there's going to be 1/2 as much, not none. After 150,000 years there will be 1.5% left. For super radioactive stuff that you have piles and piles of that's still a huge threat! It is absolutely impossible to build something that can protect this waste as long as it is dangerous because we are talking about time scales over which a lot of geological change occurs. There might even be comet strikes. The only responsible thing to do is to process it into waste with shorter half lifes, which is something we know how to do. Building a monument and pretending it is safe is just a fantasy we tell ourselves to sleep at night while we are poisoning the future.
I mean burrying monoliths may only serve to get people to dig deep and reduce the natural shield we wanted to protect people from the radiological materials.
Burying them in a place where no one will go, meaning they'll have to have a more concerted effort to dig in say the middle of a salt flat. Meaning some level of organization and technology to dig 1,000ft deep in the middle of a dry salt water lake bed a hundred miles from drinkable water.