U.S. scientists are studying the potential for shale formations to isolate spent nuclear fuel from ground water and human contact for millennia.
Chris Neuzil, a veteran hydrologist with the U.S. Geological Survey who is also studying a potential repository site in Ontario, Canada, presented his research to that end Monday at the annual conference of the American Chemical Society. Clay-rich argillaceous formations have been found to be resistant to the tiny cracks that can form in other types of rock, like granite. Sites studied in Switzerland, France, Canada and South Dakota also revealed additional properties of the formations that make them nearly impermeable to water flow, even under extreme geologic conditions. Repositories are planned in such deposits in France, Switzerland and Belgium. An ACS release said Neuzil proposed that the U.S. study the potential for storing spent fuel hundreds of yards below ground in similar formations that lack oil or gas deposits.
His research has taken place as America currently lacks a clear plan for permanent disposal of civilian nuclear waste. The Obama administration mothballed the permanent repository at Yucca Mountain in Nevada several years ago, calling for a "consent-based" approach to finding interim sites instead. Meanwhile, 77,000 tons of spent fuel resides at power plants around the country.