Independent scientists urged the Energy Department to search for ground water contaminated by radiation between the Nevada Test Site, where more than 1,000 nuclear bombs were tested, and nearby communities.
The panel recommended that the DOE dig wells in areas between the Test Site and growing rural communities that would provide an early warning if radiation has contaminated the ground water. They also noted that the DOE had not studied how earthquake faults and other underground features such as volcanic rock affect the water flow.
Scientists from the American Society of Mechanical Engineers and the Institute for Regulator Science said Wednesday night that the DOE needs to study earthquake faults, measure how fast ground water flows and determine which way the water runs from the Test Site's boundary toward people living in Amargosa Valley and Pahrump, 12 miles and 30 miles away respectively.
Critics said the DOE has not tracked or studied a single contaminated plume from 260 known underground nuclear shots at the site, 65 miles northwest of Las Vegas. The latest study concentrated on the western edge of the site.
Dennis Weber, a hydrologist for the Harry Reid Environmental Research Center at the University of Nevada, Las Vegas, said none of the known underground nuclear bomb cavities have been studied to find where radiation may have entered the ground water.
"We don't know how big the contaminated plumes are, how wide they are and the contaminants they contain," Weber said.
For example, DOE scientists discovered in the 1990s that plutonium can travel up to a mile away on microscopic particles spewed after an underground nuclear explosion, something that was not expected.
There has been no consideration by the DOE of possible radioactive contamination from the Test Site combined with that from the proposed nuclear waste repository at Yucca Mountain.
A study by David Purvance for his Ph.D. research showed water could travel through the Test Site and Yucca Mountain 25 times faster than the DOE expects. The DOE is using old ground water theories for estimating how fast the water flows, Purvance said. The panel did not consider Purvance's work.
The scientists reached conclusions similar to another expert panel studying DOE efforts to monitor the ground water at Frenchman Flat in the southeastern corner of the site. The scientists concluded that study in September 1999 with a call for more monitoring wells, more information on faults and fractures and further studies of water chemistry.
The Nevada Test Site Citizen Advisory Board asked for an independent scientific review. Chairwoman Kathleen Peterson said the board will respond to the expert review.
Genne Nelson, an Amargosa Valley resident and a Citizen Advisory Board member, asked the scientists whether possible paths leading into populated communities should have priority.
"The answer is yes," hydrologist Harold Olsen of the Colorado School of Mines said. Water contaminated with radiation could reach some areas in three or four years, he said.
Carl Gertz, in charge of DOE's environmental management program, said the agency has dug 12 shallow wells in Oasis Valley, north of Beatty and southwest of the Test Site and an additional six on Air Force land closer to the site.
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