March 18, 2014 – Shale could help solve the problem of storing radioactive waste from nuclear power plants, said Chris Neuzil of the U.S. Geological Survey at the 247th National Meeting & Exposition of the American Chemical Society. He is currently investigating a site in Ontario with the Canadian Nuclear Waste Management Organization.

About 77,000 tons of spent nuclear fuel currently sit in temporary above-ground storage facilities, said Neuzil, and it will remain dangerous for tens or hundreds of thousands of years or longer.

“Surface storage for that length of time requires maintenance and security,” he said. “Hoping for stable societies that can continue to provide those things for millennia is not a good idea.”

He also pointed out that natural disasters can threaten surface facilities, as in 2011 when a tsunami knocked cooling pumps in storage pools offline at the Fukushima Daiichi nuclear power plant in Japan.

The properties of the sedimentary rock and related clay-rich rocks make it ideal for storing the potentially dangerous spent fuel for millennia, noted Neuzil. These rock formations may be uniquely suited for nuclear waste storage because they are nearly impermeable—barely any water flows through them.

“Years ago, I probably would have told you shales below the surface were also fractured,” he said. “But we’re seeing that that’s not necessarily true.” Experiments show that water moves extremely slowly through these rocks, if at all.

Neuzil added that future glaciation probably doesn’t pose a serious threat to storage sites, as most of the shale formations he’s investigating have gone through several glaciations unchanged. “Damage to waste containers, which will be surrounded by a filler material, is also not seen as a concern.”

He noted that one critical criterion for a good site must be a lack of oil or natural gas, which could attract future interest.