"The science strongly supports that the site is suitable," Joe F. Colvin, chief executive officer of the Nuclear Energy Institute in Washington, D.C., said recently about the report. "We expect the decision process, based on scientific facts, to move forward in an expeditious manner."
Still, scientists and citizens — especially those based in Nevada — argue the mountain location is not safe enough.
Yucca Worries: Water, Volcanoes, Shakes
Judy Treichel, executive director of the Nevada Nuclear Waste Task Force, a non-profit public advocacy group opposed to the Yucca plan, argues the ground around the Yucca site is too active. 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. She says if one should erupt (an event that geologists have estimated is unlikely), "it would spew nuclear material all over the place."
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.
"In Sweden they use a copper canister — and we have very long-term data on copper's durability," says Ewing. "This material they want to use appears to be strong, but we have no way of knowing if it will break down, say, 500 years from now."
In fact, Ewing has questioned the whole approach that DOE scientists have taken in assessing the safety of the Yucca site. He argues that since so much of the evaluation has been based on estimations, an accurate conclusion about whether the mountain location would be safe is impossible. It would be better, he says, to locate other possible sites and then compare them.
"The Yucca site may be adequate," he says, "but it's difficult, even impossible to say that now with confidence."