The performance of zirconium alloy cladding and structural components in high duty U.S. pressurized water reactors

The complete paper follows. The oxidation performance of Zirconium alloy fuel rod cladding is the life limiting factor for PWR fuel assemblies. Many factors are known to influence the in-reactor behavior of cladding and structural components.These include burnup, temperature, heat flux, cycle length and coolant chemistry. Recent cladding examinations of 15 x 15 and 17 x 17 fuel assembly fuel rods thought to be different in duty, have exhibited higher measured oxide thickness than expected. Evaluation of the high measurements revealed that the tightly adherent, monolithic, solid oxide thickness was in the normal to high range of previous thickness measurements. Visual observation revealed that some of the delamination have resulted in spalling