Abstract: This paper introduces the safety design of shipping packages against brittle fracture based on fracture mechanics, and focuses on the calculation method of stress intensity factor in the condition that prevents from brittle fracture. Through analysis, the following conclusions can be drawn: the influence of nonlinear stress distribution and plastic zone are considered in the calculation of stress intensity factor in Appendix ZG of RCC-M Volume I,while comprehensive factors are considered. Therefore, the method is recommended.

Key words: shipping packages for radioactive material, brittle fracture, safety design, calculation of stress intensity factor