In 1991 a fuel recycling plant was attached to the reactor which retrieves uranium, plutonium and other actinides from reactor waste and recycles them as new fuel. (newscientist.com)
In plutonium bombs, for example, the fissile isotope is plutonium - 239, made in nuclear reactors and extracted by reprocessing spent fuel, which contains a mix of plutonium isotopes and other actinides like americium. (sciencemag.org)
Uranium, plutonium and the other actinides are then extracted electrically. (newscientist.com)