Nuclear Waste Site Managers Seek "Keep Out" Tactics Good for 10,000 Years

Hillary Mayell
for National Geographic News
July 11, 2002
The Senate vote earlier this week to authorize Yucca Mountain in Nevada as the permanent repository for at least 77,000 tons of nuclear waste will trigger a license application and approval process that is likely to take several years.

One requirement in the approval process likely to be imposed by the Environmental Protection Agency (EPA) will be the development of a warning system to alert people living 10,000 years from now of the dangers associated with the lethally radioactive nuclear waste dumps created in the early 21st century.

Designing a "Keep Out" sign that lasts for 10,000 years and still holds meaning is not an easy task.

After all, about 10,000 years ago, the Sahara was a fertile savanna, and humans were just beginning to put down their spears and figure out how to grow food. Ten thousand years from now, Earth could conceivably be populated by extraterrestrials.

In a clever bit of reverse archaeology, the U.S. Department of Energy has consulted futurists, archaeologists, materials scientists, astronomers, and others for the past decade to develop a long-term warning plan for the Waste Isolation Pilot Plant in Carlsbad, New Mexico.

Protecting Future Generations

The DOE began by forming two teams of experts in the early 1990s. They were given the task of coming up with a conceptual design for the warning system [see sidebar].

"The biggest obstacle the teams faced was the fact that you never know what the future will bring," said Kathleen Trauth, assistant professor of civil and environmental engineering at the University of Missouri–Columbia and lead author of the teams' final report submitted to the DOE in 1996.

The teams got some clues to the difficulties they faced in creating warning systems as they studied ancient monuments such as Stonehenge, the obelisks of the Aztecs, Egyptian hieroglyphics, Native American pictographs, and a wealth of other artifacts from ancient cultures.

Just to begin with, the occupants of Earth 10,000 years from now might not speak or even know of any of the languages spoken today.

Obelisks and monuments such as the pyramids are usually constructed to honor a place or deed—a purpose hardly in line with directives to "Stay Away." Overstating the danger—the "Touch one stone and die" approach—has its own pitfalls.

"Inevitably, someone will investigate the site in a non-intrusive manner. Nothing will happen to the person, and the rest of the message will therefore be ignored," the teams of consultants concluded.

The same is true of efforts to try to scare people away; museums and private collections are full of the guardian figures ancient cultures designed—unsuccessfully—to keep thieves at bay.

Need to Last

Factors like these had to be weighed against a very practical consideration: any warning system structure would have to be built of materials that are extremely durable, even in highly fluctuating climate cycles, but not susceptible to recycling or valuable enough to draw the attention of thieves.

"We used the two-team approach to get some diversity of ideas," said Trauth. "What was interesting were the commonalities between the two teams. Both agreed on the need to use multiple levels of language, a diversity of communication methods, and multiple materials to convey the warning."

The DOE's development of a final design continues, but there's no big hurry.

"The [Carlsbad] site will be actively monitored for 100 years after it closes, which is projected to be in 2033," said Roger Nelson, chief scientist at the Waste Isolation Pilot Plant.

A warning system would not be built until then, he explained, "so we have plenty of time to test new materials for durability, determine how to inscribe markers, and so on."

"There's even more time for Yucca," he added, suggesting that lessons could arise that would be helpful in setting up a warning system at the newly approved nuclear waste site.

Multiple Languages and Levels

Some of the conceptual designs the two teams considered—but did not recommend to DOE—were definitely designed to terrify potential intruders.

The current DOE design is considerably less dramatic. The nuclear waste burial site will be surrounded by an earth-and-boulder berm 33 feet (10 meters) high and close to 100 feet wide (30 meters).

Inside the berm will be granite monuments, markers, and an information center with messages ranging in complexity from, say, pictographs showing a screaming face to highly technical information.

The technical information will be written in seven languages—Navajo and the six official languages used by the United Nations: English, Spanish, Russian, French, Chinese, and Arabic. Navajo was included because it is the language of the largest indigenous group living in the region today.

The warning information will be duplicated in two rooms that will be buried beneath the ground—one inside the berm and the other outside of it—in case something happens to the above-ground structure.

Of course, no warning system will work against people determined to ignore the message.

"The warning system is designed to prevent someone from accidentally digging or drilling at the site," said Nelson. "The signs are for honest people. We cannot predict the cultural or societal setting 10,000 years from now, but we can predict human behavior.

"The only way to protect people who are dishonest," he said, "is to maintain an active presence—keep the area policed and fenced."

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