No signage says that, it was part of a purely theoretical study made by imaginative people about how long term nuclear storage could be labelled to transcend knowledge decay and cultural shift.

[…] deceased would-be despots

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This is what we do with spent fissile material

Well, I can’t speak for other countries, but most of the nuclear waste generated in the USA has never reached any sort of permanent storage. Defense waste, from making nuclear weapons, is mostly stored in underground bunkers in two states.

How and where is nuclear waste stored in the U.S.?

Remnants of the chemical processing of radioactive material needed to manufacture nuclear weapons, often called “defense waste,” will eventually be melted along with glass, with the resulting material poured into stainless steel containers. These canisters are 10 feet tall and 2 feet in diameter, weighing approximately 5,000 pounds when filled.

For now, though, most of it is stored in underground steel tanks, primarily at Hanford, Washington, and Savannah River, South Carolina, key sites in U.S. nuclear weapons development. At Savannah River, some of the waste has already been processed with glass, but much of it remains untreated.

Waste from energy generation is almost all still stored above ground on site.

After about five years, the fuel bundles are removed, dried and sealed in welded stainless steel canisters. These canisters are still radioactive and thermally hot, so they are stored outdoors in concrete vaults that sit on concrete pads, also on the power plant’s property. These vaults have vents to ensure air flows past the canisters to continue cooling them.

As of December 2024, there were over 315,000 bundles of spent nuclear fuel rods in the U.S., and over 3,800 dry storage casks in concrete vaults above ground, located at current and former power plants across the country.

Even reactors that have been decommissioned and demolished still have concrete vaults storing radioactive waste, which must be secured and maintained by the power company that owned the nuclear plant.

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A more permanent solution is likely years, or decades, away.

Not only must a long-term site be geologically suitable to store nuclear waste for thousands of years, but it must also be politically palatable to the American people. In addition, there will be many challenges associated with transporting the waste, in its containers, by road or rail, from reactors across the country to wherever that permanent site ultimately is.

Perhaps there will be a temporary site whose location passes muster with the Supreme Court. But in the meantime, the waste will stay where it is.

There is no common signage. There is no signage of that kind at all. Once we put the wastes deep enough in a stable bedrock formation it’s not going to get out for millions of years so there’s no need to signpost anything.