For three decades, however, a non-fossil fuel, uranium, also has been used to produce electricity. The first nuclear power plant went into commercial operation in 1957, in Shippingport, Pennsylvania. Since then, the use of nuclear-generated electricity has grown substantially in the United States.
Uranium occurs in nature in combination with small amounts of other elements.
Economically recoverable uranium deposits have been discovered principally in the western United States, Australia, Canada, Africa, and South America. Uranium ore must be chemically processed, enriched, and formed into pellets before it can be used as a fuel. Uranium fuel pellets are loaded into hollow tubes called fuel rods. Hundreds of fuel rods form fuel assemblies that, along with control rods, are placed into a nuclear reactor core and then submerged in water. Like fossil fuels, the resulting uranium fuel produces heat that turns water into steam.