To investigate wall-thinning impact on axial load resistance of Zircaloy-4 cladding rods after a LOCA transient, axial tensile samples have been machined on as-received tubes with reduced thicknesses between 370 and 580 μm. After high temperature oxidation under steam at 1200 °C with measured ECR ranging from 10 to 18% and water quenching, machined samples were axially loaded until fracture. These tests were modeled using a fracture mechanics approach developed in a previous study. Fracture stresses are rather well predicted. However, the slightly lower fracture stress observed for wall-thinned samples is not anticipated by this modeling approach. The results from this study confirm that characterizing the axial load resistance using semi-integral tests including the creep and burst phases was the best option to obtain accurate axial strengths describing accurately the influence of wall-thinning at burst region.

为了研究在 LOCA 瞬态后壁变薄对 Zircaloy-4 包覆棒的轴向载荷阻力的影响，在原样的管上加工轴向拉伸样品，厚度减小到 370 到 580 μm 之间。在 1200 °C 的蒸汽下高温氧化，测得的 ECR 范围为 10% 到 18% 和水淬后，加工样品被轴向加载直至断裂。这些测试是使用先前研究中开发的断裂力学方法建模的。断裂应力相当好预测。然而，这种建模方法没有预料到壁变薄样品的断裂应力略低。