Optimization and validation of the impact limiter for the cobalt-60 transport package

Abstract

The cobalt-60 transport package is a specialized container designed for the safe transportation of radioactive cobalt sources. To prevent leaks of radioactive material, it is essential to ensure the structural integrity and sealing of the transport container under accident conditions. Through finite element numerical analysis, the structure of the impact limiter located on the upper part of the transport package was optimized, and the appropriate thickness of the metal shell was determined to absorb the energy generated during a drop effectively. Based on the package's weight and the impact limiter's design, aluminum foam with a suitable density was selected as the energy-absorbing material. The analysis included calculations for horizontal, vertical, and the center of gravity over corner drop conditions. The results indicate that the stress levels within the container comply with the specifications, and the gap between the lid and the cask body during the drop process meets the required standards. Ultimately, a corner drop test of the prototypical model was conducted to compare the deformation of the container post-drop and the acceleration time history during the drop. The findings demonstrate that the design of the cobalt-60 transport package's impact limiter is sound, ensuring the structural integrity of the container. This study serves as an engineering application example for the design of impact limiters in similar containers.