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...

Read More

Radioactive Artifacts – A Radium Reprise

Two weeks ago I wrote a post about the wide variety of radioactive artifacts found in museums, such as uranium glassware, radioactive minerals, Pierre and Marie Curie lab memorabilia and Manhattan project relics. I decided to give radium-containing artifacts their own post, in part because the radium isotope Ra-226 appears in such a curious variety of items from 1898 through to the 1960s. Pretty much anything that needed to glow in the dark got coated with radium paint during that era. For example, a National Parks Service bulletin warns museum curators to keep an eye out for radium-containing chamber pot lids, light-switches, doorknobs and religious statues. (I searched long and hard, and sadly in vain, for an image of a radium glow-in-the-dark Virgin Mary or Shiva or Jesus.) Of course glow-in-the dark-radium paint is best known for making watch and compass faces as well as cockpit gauges visible at night. (A moment of silence, please, for the 4000 female workers in factories that produced these products in the 1910s and 20s. Repeated licking of the paintbrushes used to apply the radium–in order to keep said brushes pointy–took a serious toll: Many workers suffered serious illnesses ranging from bone disease to cancer.) The radium-226 found in glow-in-the-dark watches and other artifacts has a half-life of 1600 years, decaying by means of an alpha particle.  Radium-226 also eventually turns in to radon-222—not precisely the world’s most loved gas. Given the prevalence of glow-in-the-dark radium-226-containing dials and gauges in aircraft (and spacecraft), I called up Lisa Young, a conservator at the Smithsonian’s National Air and Space Museum (NASM) to find out how she deals with radioactive objects in their collection. Young explained that the government sets limits for the amount of radiation that can emerge from a museum display: 2 milli Roentgen (mR) per hour. “But we aim for under 1 mR/hr at the NASM to err on the safe side,” she added. I needed some context for what 2 mR/hour dose means so I did a back-of-the-envelope calculation: According to the Health Physics Society, people who work with radiation in the US can only be exposed to 5000 mR in a year. This means you’d have to stand in front of a radioactive museum display for at least four months, 24-hours a day to get the same amount of radiation permissible to an X-ray technician at work in a year. Since most people don’t spend more than an hour or two in a museum, this 2 mR/hour dose limit makes for a pretty low risk experience. Of course, museum staff has to monitor radioactive objects in their collection to make sure emissions are within...

Read More

Radioactive Artifacts

How do museums deal with radioactive artifacts? The question first popped in to my head when I was standing at the entrance of the Mütter Museum in Philadelphia, looking at a device built by Pierre Curie in the 1880s to measure radioactivity. Given that the device—a piezoelectric quartz electrometer—had spent decades measuring radioactivity, I guessed it probably was or had been radioactive itself. Then it occured to me that the devices used by Pierre and Marie Curie aren’t the only kind of radioactive artifacts found in museum collections. German chemist Martin Heinrich Klaproth discovered uranium in 1789, and by 1830 the radioactive element was being used heavily as a yellow-green colorant in all sorts of glassware (before people even knew what radioactivity was). By the early 20th century, uranium oxide was used to color the incredibly popular orange-red ceramic Fiesta tableware favored by Andy Warhol and many others. And radium-226 was used to paint watches, aircraft gauges, door knobs, religious icons, light switches and even chamber pots so that they glowed in the dark. Radioactivity also became a health fad. Look no further than the “Lifetime Radium-Vitalizer Water Jar,” from the 1920s, which added radiation to water by means of a chunk of uranium ore at the bottom of the vessel. In addition to quack health products, radioactive artifacts are sometimes natural history museum minerals as well as relics and equipment from the Manhattan project and all subsequent nuclear testing. Since we are all exposed to low-levels of radiation daily–heck, our own bones emit radiation to those around us–the issue is whether a particular artifact emits enough radiation to present a health hazard to museum staff and the public. “Whenever a new artifact comes into the museum, the first thing I do is run a Geiger counter over it,” said Anna Dhody, the Mütter Museum’s curator, when I called to ask about Pierre Curie’s electrometer. You often don’t know the precise life trajectory of an artifact, she explained, and it’s wise to be precautious, particularly with donations. Pierre Curie’s electrometer had been professionally decontaminated by a nuclear physicist, Dhody said, but she couldn’t provide more details because it had happened before her tenure at the museum. She suggested I call up the National Atomic Testing Museum (NATM), whose whole modus operandi is to deal with artifacts related to the more than 1000 nuclear tests that took place from 1951 onwards at the Nevada Test Site, about 68 miles outside Las Vegas. “You don’t want to fool around with radioactive artifacts,” Karen Green, the NATM’s curator told me. She told me that the artifacts in the NATM, such as radiation...

Read More