Currently, the nation's 104 operating power reactors create about 2,000 tons of the material each year, adding to 70,000 tons stored mostly at those power plants.
Much of that material is stored in concrete-lined pools, where water keeps the fuel rods cool. More secure, above-ground cask storage systems can also be built.
Even before spent fuel at Japan's doomed Fukushima reactor complex was feared to be overheating, concerns over the safety of spent fuel at U.S. facilities were being reiterated.
Under the 1982 Nuclear Waste Policy Act, the U.S. Department of Energy became the agency responsible for finding disposal solutions for spent nuclear fuel.
In 2002, Congress approved Yucca Mountain, Nev., as the site of a national nuclear waste repository. Under an Obama administration edict, however, the project was canceled and a Blue Ribbon Commission was appointed to seek alternatives.
Because the federal government's long-range plan for a national geologic repository for such waste has stalled, Plant Vogtle is following in the footsteps of many other nuclear plants by building above-ground cask storage sites that can accommodate larger volumes of nuclear waste for longer periods.
Cask storage is already in place at the Southern Nuclear's Hatch and Farley plants. Those sites are among 51 licensed cask facilities in 47 facilities in the U.S., according to the NRC.