High-Level Radioactive Wastes

Spent nuclear fuel and other high-level wastes generally will come from nuclear reactors and nuclear weapon facilities. Items in this category include spent nuclear fuel—the radioactivity originally used to run the nuclear reactor that is no longer radioactive enough to be useful—and waste materials left from the production and processing of nuclear weapons.

Currently, much of the spent nuclear fuel rods are being kept on-site at nuclear reactor facilities either in water pools (the water acts as a shield and also helps dissipate the heat generated by the fuel rods) or in dry casks. The fuel in these rods are waste because it no longer has enough uranium to be useful. Within approximately 90 days, nearly half of the radioactivity is gone and within about a year, about 80 percent of the radioactivity is gone. The remaining radioactivity has half-lives ranging from several years to thousands of years.

Spent nuclear fuel and other high-level wastes are being kept on-site because the United States has no disposal site for this waste. Some sites have been evaluated, but controversies remain. While members of the scientific community believe that safe disposal options currently exist, they also believe that a waste site should not be considered a permanent site (one where the waste would or could be there forever), but should instead be a site where the waste is retrievable. This would allow the application of new technologies and methodologies to the wastes that we haven’t yet discovered. Even if the waste is retrievable, however, it would need to be continuously monitored to assure there is no contamination of the environment.

Nuclear weapons waste is the responsibility of the Department of Energy. Most of this waste is generated from the “cleanup” of sites where nuclear weapons were manufactured. At these sites, parts of buildings, soils, and ground and surface waters are radioactively contaminated. Some sites have been cleaned up and cleared for other uses, while the decontamination process continues for many of them.