Patent Number: 053735412
Section: abstract

A nuclear fuel rod cladding for a water moderated and nuclear reactor comprises an inner portion of Zircaloy 4 and an outer portion of a zirconium-based alloy which contains by weight, besides zirconium and unavoidable impurities:. 0.35% to 0.65% tin PA1 0.18% to 0.25% iron PA1 0.07% to 0.13% chromium, and PA1 0.19% to 0.23% oxygen,. with the sum of the iron, chromium, tin, and oxygen contents being less than 1.26% by weight. It may alternatively or additionally comprise 0.80% to 1.20% by weight niobium and then the oxygen content is in the range 0.10% to 0.16% by weight. The thickness of the outer layer is 10% to 25% of the total thickness of the cladding. In a modification, up to 0.5% of iron, chromium, niobium is replaced by an equivalent content of vanadium.