Fuel rods contain the nuclear fuel that is used to operate nuclear power plants. Fuel rods consist of a cladding tube and the fuel pellets.
The cladding tube usually consists of an alloy of the metal zirconium (approx. 90 %) and other metals such as tin, iron, chromium, nickel or niobium ("zircalloy"). The so-called pellets, which contain the nuclear fuel, are stacked inside. Common cladding tubes are three to four metres long, with a diameter of a good one centimetre.