Out of Sight
[Above] Researchers from Berkeley Lab's Earth Sciences Division and Visualization Group teamed up to produce graphical images of the 3-D site scale model of Yucca Mountain, the proposed location of a permanent nuclear waste storage facility. This image shows where water travels if released from the boundaries of the facility.

by Lynn Yarris

Ever since human beings first learned to use the energy from fires, the quest has been to keep the fires burning. A few decades ago, the ultimate answer to this quest was thought to be nuclear fission-the splitting of atomic nuclei. More than a hundred nuclear power plants were built in this country alone before high costs and environmental concerns, particularly regarding the disposal of nuclear waste, brought new construction to a halt and caused some existing plants to be shut down. Still, the waste continues to accumulate. In the U.S., it already exceeds 24,000 metric tons and is expected to approach 100,000 tons sometime in the next century. What to do with all this waste?

The U.S. Department of Energy (DOE) is trying to decide if Yucca Mountain, a desolate, semi-arid formation of volcanic rock about 100 miles northwest of Las Vegas, is a suitable site for the nation's first permanent underground geologic repository for high-level nuclear waste. If the site is suitable and a license application is approved by the Nuclear Regulatory Commission, current plans call for DOE to begin transporting nuclear waste to the repository by the year 2011. But first, its hydrogeologic conditions must be thoroughly characterized.

The target date for the license application is 2002. Towards this end, researchers within the nuclear waste program of Berkeley Lab's Earth Sciences Division (ESD) have developed a three-dimensional site-scale computer model of the Yucca Mountain site that can be used to characterize hydrogeologic conditions under a wide range of different simulation scenarios. ESD researchers in this program have also played a vital role in on-site field testing of water movement and thermal conditions.