The nuclear fuel cycle consists of front-end steps that prepare uranium for use in nuclear reactors and back-end steps to safely manage, prepare, and dispose of used—or spent—but still highly radioactive spent nuclear fuel.
UUranium is the most widely used fuel by nuclear power plants for nuclear fission. Nuclear power plants use a certain type of uranium—U-235—as fuel because its atoms are easily split apart. Although uranium is about 100 times more common than silver, U-235 is relatively rare at just over 0.7% of natural uranium. Uranium concentrate is separated from uranium ore at uranium mills or from a slurry at in-situ leaching facilities. It is then processed in conversion and enrichment facilities, which increases the level of U-235 to 3%–5% for commercial nuclear reactors, and made into reactor fuel pellets and fuel rods in reactor fuel fabrication plants.
Nuclear fuel is loaded into reactors and used until the fuel assemblies become highly radioactive and must be removed for temporary storage and eventual disposal. Chemical processing of spent fuel material to recover any remaining product that could undergo fission again in a new fuel assembly is technically feasible, but it is not permitted in the United States.