Application of Monte Carlo method in the design of shielding scheme for cobalt source containers

Background Radiation protection and the safety of radiation sources are critical in industrial applications. The Basic Standard for Protection against Ionizing Radiation and Safety of Radiation Sources is a key technical standard in China, establishing personal dose limits for occupational exposure and the public. Ensuring that the radiation dose from the transport of radioactive sources remains below these limits is essential. Cobalt-60 (⁶⁰Co) sources are widely used in industrial applications, and their transport containers must provide adequate shielding to minimize radiation exposure.

Purpose This study aims to evaluate and optimize the shielding performance of a cobalt source container to ensure compliance with national standards and to protect personnel during transportation. The research focuses on analyzing the shielding effectiveness under different loading configurations and verifying the container’s performance against regulatory requirements.

Methods The shielding analysis was conducted using the Monte Carlo method and MESH grid mapping. The study considered the activity of individual radioactive sources and their loading configurations, focusing on four eccentric loading schemes. The dose rate levels were analyzed at various angles, and MESH grids were used to visualize the spatial distribution of dose rates on accessible platforms.

Results The analysis demonstrated that the cobalt source container meets the national standard (GB). The dose rate levels at different angles and positions were found to be consistent with regulatory limits. The MESH grid visualization provided a clear understanding of the dose rate distribution, confirming the container's shielding performance under the tested configurations.

Conclusions The research validates the shielding effectiveness of the cobalt source container and provides a systematic approach for evaluating and optimizing shielding designs. The findings contribute to ensuring safe transport of radioactive sources and compliance with radiation protection standards.