Method for determining primary radiation shielding thickness of industrial X-ray-generating devices

The United States National Council on Radiation Protection and Measurements (NCRP) and American National Standards Institute (ANSI)/Health Physics Society (HPS) reports typically are used as references during shielding evaluations of industrial X-ray-generating devices (XGDs). Considering the early date of publication of these reports, the types of some of the x-ray generators used in their experiments (i.e., generators for diagnosis, not industrial applications), the lack of available voltage types, and the non-intuitive application of the formulae, it is necessary to validate and improve the existing evaluation methods and data in consideration of the characteristics of industrial devices that are widely used today. To this end, we selected a representative industrial X-ray generator and measured its dose rate using a dose-rate meter with varying lead shielding thicknesses and tube voltages. By statistically analyzing the relationship between these variables, new formulae for shield-thickness evaluation according to fine tube-voltage increments, along with all of the related data, were derived. By using the information obtained in this study, the required lead thicknesses for industrial XGDs can be determined at different tube voltages in order to satisfy users' dose-rate requirements and ensure the radiation safety of workers.