Fracture of Zircaloy-4 Fuel Cladding Tubes with Hydride Blisters

The influence of hydride blister on cold worked stress relieved Zircaloy-4 cladding tubes fracture toughness at room temperature was studied using hoop tensile tests and plane strain tensile tests. The experimental macroscopic fracture stress and strain values and an elastic-plastic finite element analysis of the mechanical tests with the CAST3 M code were used to calculate the J-integral and estimate the fracture toughness for several blister depths from 120 to 240 μm.