Radiological safety assessment of monazite industry worker due to NORM inhalation

Monazite is used as a raw material for the production of rare earth elements. The workers in the monazite industry are exposed to radiation from the raw material. Therefore, internal radiation dose should be assessed for radiological safety assessment of the workers. The objective of this study is to assess the internal radiation dose to workers of the monazite industry in Korea by means of measured particulate. Particulate properties, including size distribution, density, shape, and radioactivity concentration were analyzed. Then, the internal radiation dose coefficients were derived using the IMBA software. Work scenarios were derived by identifying the work time. Finally, internal radiation doses were calculated with the collected and calculated data. The internal radiation dose ranged from 7.48 × 10-3 to 3.25 × 10-1 mSv y-1 with dose difference by orders of magnitude. It is highlighted why such data should be directly collected at sites to realistically assess radiation dose to workers.