抄録
It is often observed that the data of the time to failure of Zircaloy tubes obtained in the internal pressurization SCC tests vary widely even though the same testing condition, such as the applied hoop stress, iodine concentration, test temperature and texture, is used. In order to keep the failure probability of Zircaloy tubes very small, it seems important to determine the distribution of the time to failure, or the failure probability, of Zircaloy tubes for the SCC test results.
A study has been performed to establish the functional form of the distribution of the time to failure by using the statistical approach adopted in the study of strength and fracture of solids. The results revealed that the distribution of the failure probability could be described by the Weibull distribution. An attempt was also made to apply the present method to evaluate the failure probability of the Zircaloy cladding tubes with stress distribution by combining the data of SCC tests with the behavior of fuel rods analyzed by FEM code.
