Abstract: The decommissioning of cobalt sources in large γ-irradiation facility is accompanied with some risk, and the radiation safety of operators and the environment during decommissioning should be considered. The experience of the cobalt source decommissioning operation completed by Hunan Irradiation Center in the first half of 2024 is summarized in this paper. The decommissioning operation plan design, operation practice, risk analysis, emergency management and other aspects are described. Good decommissioning practices ensure the health of radiation workers and environmental safety; the good practice can be used as reference for the decommissioning of radioactive source of irradiation equipment.

Key words: irradiation device, decommissioning of cobalt source, radiation protection