Confronting the nuclear legacy--Part III. Can nuclear waste be stored safely at Yucca Mountain?

In the half century of the nuclear age, the U.S. has accumulated some 30,000 metric tons of spent fuel rods from power reactors and another 380,000 cubic meters of high-level radioactive waste, a by-product of producing plutonium for nuclear weapons. None of these materials have found anything more than interim accommodation, despite decades of study and expenditures in the billions of dollars on research, development and storage. The fuel rods, which accumulate at the rate of six tons a day, have for the most part remained at the nuclear reactors where they were irradiated, in water-filled basins and, in some cases, in steel containers on concrete pads. The high-level waste occupies huge, aging tanks at government sites in Washington State, South Carolina, Idaho and New York State. Some tanks have leaked, making conspicuous the lack of a more permanent, efficient and coherent solution for the nuclear waste problem. In 1987 the federal government narrowed to one its long-term options for disposing of this waste: storing it permanently in a series of caverns excavated out of the rock deep below Yucca Mountain in southern Nevada. Since then, the U.S. Department of Energy, which is responsible for the handling of practically all the high-level nuclear waste in the U.S., has spent $1.7 billion on scientific and technical studies of whether such a repository below the mountain might safely store waste. From the very beginning, however, the state of Nevada has strongly opposed the project, hiring its own scientists to study the mountain. Whether the state can block the project altogether is uncertain; its active opposition, though, is sure to complicate an undertaking that is already very difficult. At the same time, legal issues make it necessary that something be done. Since 1982, nuclear utilities in the U.S. have paid $12 billion into a Nuclear Waste Fund and a related escrow account. In return, the DOE pledged to build a national repository and begin accepting the utilities’ waste in 1998. Yet even if a repository is actually built at Yucca Mountain, it could not begin accepting waste until after 2015, according to the latest estimates. This has prompted the utilities to file suit in the U.S. Court of Appeals in Washington, D.C., to find out exactly what they are owed in two years’ time. In addition, legal agreements with the states of Washington and South Carolina oblige the DOE to process the highlevel tank waste into glass logs, for eventual disposal in a repository. Whether it makes sense at this time to dispose permanently of spent fuel and radioactive waste in a deep geologic repository is hotly disputed. But the Nuclear Waste Policy Act amendments of 1987 decree that waste be consolidated in Yucca Mountain if the mountain is found suitable. Meanwhile the spent fuel continues to pile up across the country, and 1998 looms, adding urgency to the question: What can science tell us about the ability of Yucca Mountain to store nuclear waste safely?