"Caution: radiation, this invisible poison will destroy your DNA, this poison will destroy all who approach it. Those who do cannot solve the following puzzles ensure their own demise" followed by some d&d ass mechanical puzzle locks that test if someone understands the basics of chemistry from identifying uranium and plutonium on a periodic table to demonstrating an understanding of alpha, beta, and gamma radiation as a byproduct of nuclear fission.

But you want all that past the big scary "no honor" stuff. You need to scare away every human society from tribes focused on things like honor and taboos to curious scientific societies. To present a puzzle that very clearly states "you will definitely die in this way if you dig without understanding how to solve these puzzles and still making them dig through concrete behind those puzzle doors is a good deterrent.

Everytime this comes up the practical answer is to just not mark it and bury it as deep as you can.

If your mark it as poison, or honestly and descriptively, people will try to use it as a weapon, or a manhood test, or whatever dumb shit might happen. The patronizing warnings won't be legible to survivors and they're, quite frankly, embarassing.

My money is on descriptive warnings buried with the waste that only get exposed if it's exposed. You still run the risk of people trying to weaponize it but at least they aren't being attracted to the site by the warnings themselves.

The issue they were dealing with was that the material would be hazardous longer than almost any known language has been spoken. We could bury the waste, civilization collapses, and then rebuilds and it would still be hazardous.

So how do you convey the danger in a way that will stick?
The messages as written are more the point to convey, rather than literal words.
The pyramids had big warnings of bad things if you break in, but combined with the decoration we were convinced something special was there.
So how do we structurally convey "this is not a place of honor”?
They had notions like covering the site with trash and so on. You don't bury a king with discarded animal bones, and you don't pile trash on something you want to honor.

I think they ultimately decided that the best path was to largely leave it unmarked, but case it in enough hardened concrete that anyone in the future would realize we weren't totally unsophisticated, and at that layer start putting more directed messages referencing chemical elements.

Some of their diagrams were pretty good though.

If you stand on a ledge, it could fall. If you fall, you die. Don't stand on the ledge.
Digging here is like standing on a ledge.

I was also really taken with the notion of genetically engineering cats to glow near radiation, and spreading the belief that glowing cats are dangerous.