Radiation safety analysis of a generic 2 MCi multipurpose gamma irradiator

This study presents a three-dimensional model of a generic 2 MCi multipurpose gamma irradiator, developed to perform a comprehensive radiation safety analysis based on an existing reference design. Using MCNP and QAD-CGGP codes, the gamma dose rate distribution within the irradiation room was calculated for a 3 MCi Co-60 source board. The objective was to assess the effectiveness of the shielding system in meeting regulatory dose limits for occupational and public exposure. The dose rates in the irradiation room (10¹¹ μSv/h within a 270 cm radius), the very low dose rates above the pool (10^-6 μSv/h), and the dose rates in the personnel access lanes (maximum 6.55 μSv/h) all remain below the regulatory limit of 10 μSv/h. The results demonstrate that the facility's design ensures full compliance with regulatory requirements across all zones, including areas routinely accessed by personnel, thereby confirming its adequacy in protecting both workers and the surrounding environment.