Nuclear Power in a Warming World

Because the spent fuel removed from a nuclear reactor is highly radioactive, it must be disposed of in a way that protects the environment from contamination and living organisms from exposure. Radioactive isotopes can be spread by air or water, and can also become part of the food chain. While the radioactivity of spent fuel drops with time, according to a 1995 National Academy of Sciences study, the “peak risks [from a repository] might occur tens to hundreds of thousands of years or even farther into the future.” Isolating spent fuel from the environment is therefore a highly demanding task—for comparison, human civilization has existed for only some 10,000 years. Several potential ways of handling spent fuel in the long term have been proposed—none of which are ideal. These include burying the waste below the seabed, launching it into outer space, and storing it on remote islands. However, the international scientific consensus is that spent fuel and other high-level waste should be stored underground in a “geologic” repository, where the geological properties of the surrounding area would provide the long-term stability needed to isolate the waste from the environment. The waste would sit inside tunnels drilled deep into the earth. UCS concurs with this consensus, and believes that such a repository—if properly sited and constructed—can protect the public and the environment for tens of thousands of years. However, the choice of a repository location must be based on a high degree of scientific and technical consensus. When spent fuel is isolated in a geologic repository, the hazard to the public results from the slow corrosion of spent fuel and leakage of radionuclides into the environment—primarily through groundwater. The risk profile of a repository depends strongly on the geochemistry of the site, and changes with time as the result of radioactive decay. Sweden, Switzerland, and the United States have decided to build such repositories, but none have begun to do so. Only the United States has chosen a potential site—at Yucca Mountain in Nevada. However, this facility faces several political and technical hurdles before it can be licensed. For example, although the site is unique among those proposed worldwide because it sits above the water table, leaks from the repository could still contaminate groundwater. In fact, analysts have found that rainwater travels much more rapidly through the layers of the proposed repository than originally believed, and thus that any leaked waste would also reach the groundwater more quickly. Fortunately, there is no immediate need to open a permanent repository, as interim storage of spent fuel in dry casks at reactor sites is an economically viable and secure option for at least 50 years—if such sites are hardened against attack. New reactors could build in more robust interim storage from the beginning. However, the federal government must improve the security of these