Corrosion

A corrosion resistant nuclear fuel element. It comprises: an elongated cladding container formed from a zirconium alloy tube consisting essentially of by weight percent 0.5 to 2.0 percent tin, 0.24 to 0.40 percent of a solute composed of copper, nickel and iron, and the balance zirconium; and a central core of a body of nuclear fuel material selected from the group consisting of compounds of uranium, plutonium, thorium and mixtures thereof disposed in an d partially filling the container so as to leave a gap between the container and the core and an internal cavity at one end of the container an enclosure integrally secured and sealed at each end of the container and a nuclear fuel material retaining means positioned in the cavity