Zirconium niobium tin alloys for nuclear fuel rods and structural parts for high burnup

Corrosion resistant nuclear reactor components comprising an alloy consisting essentially of from 0.5 to 3.25 weight percent niobium, from 0.3 to 1.8 weight percent tin, from 0.003 to 0.015 weight percent of silicon, from 0.005 to 0.02 weight percent carbon, and from 0.04 to 0.10 weight percent oxygen, the balance of said alloy being essentially nuclear grade zirconium with incidental impurities and imparted with a microstructure of beta niobium second phase precipitates distributed uniformly intragranularly and intergranularly forming radiation resistant second phase precipitates in the alloy matrix so as to result in increased resistance to aqueous corrosion to that of Zircaloy when irradiated to high fluence, and wherein the second phase beta-niobium precipitates in said alloy have an average diameter of from about 30 to 150 nm.

A structural part for a nuclear reactor fuel assembly comprising a zirconium alloy consisting essentially of from 0.5 to 3.25 weight percent niobium, from 0.3 to 1.8 weight percent tin, the balance of said alloy being essentially nuclear grade zirconium with incidental impurities and having a microstructure of beta niobium second phase precipitates distributed uniformly intragranularly and intergranularly forming radiation resistant second phase precipitates in the alloy matrix so as to result in increased resistance to aqueous corrosion to that of Zircaloy when irradiated to high fluence.

A fuel rod cladding tube for a nuclear reactor fuel rod comprised of an alloy consisting essentially of from 0.5 to 3.25 weight percent niobium, from 0.3 to 1.8 weight percent tin, the balance of said alloy being essentially nuclear grade zirconium with incidental impurities and having a microstructure of beta niobium second phase precipitates distributed uniformly intragranularly and intergranularly forming radiation resistant second phase precipitates in the alloy matrix so as to result in increased resistance to aqueous corrosion to that of Zircaloy when irradiated to high fluence.

The nuclear fuel rod cladding tube as in claimed 13 wherein the alloy further consists essentially of from 0.003 to 0.015 weight percent of silicon, from 0.005 to 0.02 weight percent carbon, and from 0.04 to 0.10 weight percent oxygen.