Zircalloy is used as fuel cladding in the PWR fuel assembly. (Source: © Yakov / stock.adobe.com)

An alloy of zirconium with other metals used as the cladding of nuclear fuel in most nuclear reactors. Other metals used in the alloy include tin, niobium, chromium, iron, or nickel. Zircalloy has high corrosion resistance, absorbs almost no neutrons, and is stable under high radiation and high temperature conditions. However, at temperatures above 1,500 K, hydrogen may be released when zircalloy reacts with water vapour.