Nuclear Waste Signage Must Last 100,000 Years: Will the Messages Be On Sapphire Disks With Platinum Print Or Pieces Of Broken Pottery?
Humans have been around for 50,000 years and the nuclear waste we’re producing today is going to be harmful for 100,000 years. So how do we create signs that alert our descendents about enormous underground nuclear waste repositories when we don’t know what language they will speak?“A vast underground space with all sorts of curious objects inside... This sounds exactly like where future archeologists are going to want to go digging,” said Cornelius Holtorf, an archeologist at the Linnaeus University in Sweden, who spoke at a Euroscience Open Forum (ESOF) session. The session focused on how one formulates a warning message with a 100,000-year lifetime when humans have never built anything that has lasted one-tenth of that time. If we say ‘don’t dig here,’ you can bet that it will only make the site more enticing, Holtorf said. Linguists, archeologists, scientists, engineers and historians have been tackling the issue for decades. Some potential solutions sound a tad wacky: Namely the idea to create an atomic priesthood that carries on an oral tradition about the waste. Other solutions sound temptingly techie, but perhaps a tad expensive: For example, Patrick Charton from the French National Radioactive Waste Management Agency showed the ESOF audience a 25,000 € sapphire disk which could hold warning messages in platinum script. The disk satisfies the longevity criterion: It has a lifetime of at least a million years, he said. Since 40,000 pages of information can be deposited in platinum on the disk, warnings and technological specs could also be inscribed in a potpourri of languages, he added. But the sapphire-platinum solution costs a lot of money. And this is a serious down side, notes geologist Marcos Buser, who has worked with the Swiss Federal Nuclear Safety Commission in this Spiegel article. (It's in German.) “The material cannot be valuable, otherwise it will be stolen,” said Buser. He favors putting warning messages on pottery sherds instead, since pottery has a long lifetime and broken pieces are less likely to be stolen. I can’t think of two more disparate solutions. I’m guessing something midway between the two will eventually be chosen. For example, Charton mentioned that researchers are trying to replace the expensive sapphire with cheaper, long-lasting glass. Whatever is eventually chosen, I’ll bet archeologists of the future scrutinizing the artifact-to-be will marvel about current-day humanity’s desire for energy—a desire so great that we produced waste to last 100,000 years.