But, as many scientists point out, there are factors such as volcanoes and earthquakes that could disrupt even deep underground holdings. According to legislation passed in 1987, the federal government should have begun operating a permanent underground storage site by 1998 at Nevada's Yucca Mountain, located about 100 miles northwest of Las Vegas. Tunnels burrowed 600 feet below the mountain's surface would host about 70,000 tons of waste. We expect the decision process, based on scientific facts, to move forward in an expeditious manner. Nevada ranks third in the country for seismic activity and M.I.T.'s Macfarlane points out there are three volcanic cones located within 10 miles of Yucca Mountain.
Water is another big worry.
Nevada geologist Steve Frishman and others have found that water seeps through the mountain much faster than researchers originally thought. If water can reach the cask-contained waste, Treichel argues, then it can also carry the radiation to groundwater supplies. Finally, some scientists have questioned the durability of the material that would contain the nuclear waste. According to the plan as it's now written, the canisters would be built from a nickel alloy. Although studies show the material to be strong, there are no long-term studies on its performance.