If we found anything resembling this today (presumably in some language we don't understand or by a culture we assume isn't stating this as a fact of science), the first thing that would happen is someone would dig it up.
Maybe the safest solution is no marking.
It seems plausible that over a long enough scale of time, the only reliable way to communicate "everyone who messes with this will die" regardless of language is by ensuring that everyone who messes with it does die.
That's a positive outcome, because anyone with a radiological sensing system would then figure out what it is.
From https://www.bbc.com/news/science-environment-60528828:
Prof Claire Corkhill, a nuclear materials expert from Sheffield University, told the BBC the spike was "quite localised" and there had been increases along the main routes in and out of the zone around the reactor.
"The increased movement of people and vehicles in and around the Chernobyl zone will have kicked up radioactive dust that's on the ground," Prof Corkhill said.
"Provided there's no further movement, it should decrease again over the next couple of days."
But any military activity in the zone is concerning.
A large part of the film is all about how to mark the site, deter future civilisations from digging it up:
I met a traveller from an antique land,
Who said—“Two vast and trunkless legs of stone
Stand in the desert. . . . Near them, on the sand,
Half sunk a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them, and the heart that fed;
And on the pedestal, these words appear:
My name is Ozymandias, King of Kings;
Look on my Works, ye Mighty, and despair!
Nothing beside remains. Round the decay
Of that colossal Wreck, boundless and bare
The lone and level sands stretch far away.
It's generally the 'hot' stuff early on (right out of the reactor, and sits in the water tanks for a few decades) throwing off gamma (γ) radiation that will really get you.
IIRC Litvinenko was killed with something like 10^-4 g (hundred micrograms) of polonium-210 added to his food. That stuff is quite active (half life of less than half a year), but still.
This whole idea is almost aggressively stupid. We're talking about a bigger gap than all of recorded history.
The civilisation we're trying to communicate with either doesn't see this waste heap as even a minor threat, or the situation is so dire that radiation poisoning doesn't matter. This is even more futile than the vikings trying to send us a message that we need to keep an eye out for depleting our lumber stocks.
Try analysing lead in water or mercury in soil as easily.
But what are you going to do with the waste that is highly radioactive for thousands of years, what if everyone forgets how to read! Think of the hypothetical children!
> [Thomas Sebeok] proposed the creation of an atomic priesthood, a panel of experts where members would be replaced through nominations by a council. Similar to the Catholic church – which has preserved and authorized its message for almost 2,000 years – the atomic priesthood would have to preserve the knowledge about locations and dangers of radioactive waste by creating rituals and myths.
Se: https://asimov.fandom.com/wiki/Scientism
This is the extract in question from the link above:
"In addition to the technician-priests (an atomic priesthood that controls the technology of nuclear power) from Terminus who travel to the worlds of the Four Kingdoms, the church also recruits priests from among the native populations of those worlds.
They travel to a Temple School in Terminus City, where they are taught the operation (though not the theoretical underpinnings) of the Foundation's technology, along with more traditional religious instruction in church dogma, theology and ethics.
Any novitiate priest at the Temple School who is bright enough to see through the mystical surface to the scientific principles underneath remains on Terminus to become a research student. The rest return to the Four Kingdoms to form part of the priesthood." (End quote)
Basically, disguise the knowledge within the rituals but make the rituals good enough so that the knowledge can be transmitted to the future generations.
It's funny because there's a trend these days of scientizing everything, including religion, and what these guys proposed instead is to religionize science. They think they need to disguise wisdom with myth, as if that's what religion is. It seems they don't understand religion - not good!
https://dzienniklodzki.pl/serce-lodzi-mali-straznicy-przepro...
Googling it now it seems at one point is was going to get adapted to film [1], but seems like that went nowhere.
[1]: https://reactormag.com/ken-lius-the-message-to-get-big-scree...
SYS!00026
SYS!00153
Somebody responded to that with an ASCII art floppy, something like
+--+-+--\
| +-+ |
| O |
| |
+-------+
The essence of the nuclear "waste" puzzle is that nuclear waste is not waste. that is we have used less than 3% of the energy that is there. If you want it to be left undisturbed the last thing you want to do is call attention to it.
It does seem like an excessive amount of work to theoretically save a few lives tops in a theoretical future cataclysm.
Seriously, filling the hole and covering it should be a one-time operation. Although in a sense you're right, if society collapses suddenly all that stuff stays there. But then we have a lot of other problems.
You pre-wire the site for demolition and set a countdown timer: if the counter is not resent regularly it goes down to zero and the charges go off sealing things off.
Society is needed to prevent closing things off, so if it's gone then it happens without intervention.
If they accidentally go off, then things are fail-safed closed, and you have to expend resources to re-open things. If you don't want (or have) the resource to re-open then you don't have to worry about it.
Someone else knows better here, but I think a lot of the waste exists because we don't burn it all in nuclear reactors - in which case why not make reactors that can burn it rather than leave it as waste.
It makes sense to a degree that if the usage is circular, problem solved. But am I wrong? Is it theoretically or actually possible to achieve 100% “reclamation”?
That kinda assumes that technology always progresses forward and there are no regressions and dark ages. 10k years is a long time. The Great Pyramid of Giza was built roughly 5k years ago, so we are aiming here for twice that long. During that time many empires have risen and fallen. That is a lot of time for technical things to go forgotten.
The entire thing is an exercise in hyper-transgenerational communication (if I might turn a phrase).
Surely the future human being would have ways to detect nuclear waste before digging around, regardless if there is any sign?
And even in worst scenario, they did dig without testing -- they will learn their lesson very quickly. It's not like one accident would be too catastrophic, in the grand scheme of things.
Technology doesn't inevitably progress. Its certainly possible that we lose even relatively simple nuclear detection technology (e.g. a Geiger counter) in the future (or fail to deploy it - I wonder how many construction sites have a radiation check performed?)
And I believe, if we had an idea nuclear waste store, we'd not be able to detect it - i.e. the excess radiation outside of the store would be comparable to natural variation between locations on the earth.
That one's a classic
But at the moment most waste is held on-site and not reprocessed as sub-seabed disposal, waste reprocessing and even constructing a land-based waste depository have all been prohibited. So it's actually ended up more dangerous than it needs to be.
I've used this a comment on more than block of code.
I'm not sure what it is about these warnings but I always enjoy reading through them and thinking about how they might be perceived but future generations.
https://rmit.instructure.com/courses/87565/modules/1193362
Nothing other that speculative solutions have so far been proposed.
In the same module, I also address the problem of communicating with alien intelligence using the Voyager 'Golden Record' as an exemplar.
The value of giving students such impossible speculative tasks is that it tests the limits of the students' thinking. Also, they really enjoy these kind of things :)
Imagine you go to put solar on your house and some people show up screaming "What if Dr. Zaius cuts himself on one of those panels a million years into the future?". That's what they did every step of the way with nuclear.
What’s actually wrong with above-ground dry cask storage? The best long term warning system is to keep the actual waste on display and on people’s minds.