The 10,000-Year Test

Abstract

N uclear. The word has made its home in our generation, as a prefix before such terms as power, weapons and even medicine. But three decades after the first fullscale nuclear power station went on line, four decades after an atomic explosion mushroomed over Hiroshima, we are still searching for a place to store the legacy of our nuclear age. Accumulating in huge water pools at the 106 licensed nuclear power plants across the United States, there are approximately 15,000 metric tons of spent uranium fuel, still highly radioactive but unusable. The Department of Energy (DOE) has estimated that by the turn of the century, the fuel figure will near 50,000 tons. According to the Nuclear Regulatory Commission (NRC), which licenses the power plants, almost all of the plants will reach their present authorized capacity for storage within the next decade, and storage facilities will have to be expanded. With the last days of 1987 at its heels, Congress passed an amendment to the Nuclear Waste Policy Act of 1983, which is the blueprint for the nation's plans to dispose of radioactive waste by burying it below ground. Abandoning part of the plan that required the DOE to characterize simultaneously three possible sites for a repository of high-level waste, Congress shifted gears and authorized the department to proceed in studying what it regards as the most promising site, at southern Nevada's Yucca Mountain on land adjacent to the Nuclear Weapons Testing Site (SN: 1/2/88, p.7). According to the DOE, the present plan is to dig into the stone heart of Yucca Mountain and build the repository there. Once filled to capacity with 70,000 tons of waste around the year 2030, the repository will be completely sealed off and its entrance shafts refilled. The artificial, engineered barriers of the repository combined with the sheer bulk of Yucca Mountain will isolate the waste and protect the surface environment. While it sounds simple, the plan is complicated by one sobering fact: The radioactive waste to be placed in the repository will remain dangerous for more than 10,000 years. The canisters that contain the fuel are designed to resist corrosion for only 300 to 1,000 years. After that, it is up to the geology of Yucca Mountain to keep the radioactive atoms, called radionuclides, from leaking into the environment. During the next five years, the DOE will be working with the U.S. Geological Survey (USGS) and several national and private laboratories to see if Yucca Mountain can rise to the occasion.