Molybdenum-99 is a critical radioisotope for producing diagnostic radiopharmaceuticals labeled by technetium- 99m. In this study, the shielding of hot cells used in radiochemical process facilities for industrial 99Mo production via fission of domestic LEU targets was investigated. A calculation method based on MCNP6 simulations was proposed and evaluated by some experimental data. The results showed that the calculated dose rate values should be multiplied by 1.3 from a conservative point of view and then values compared with the permissible dose rate limits. The ISODOSE graphs showed that although a one-layer hot cell with Barite concrete (BA) walls of 80 cm is not enough for radiation-safe work on a hot batch, a one-layer hot cell of BA with 90 cm walls, twolayer BA(80 cm) + Lead(3 cm) and BA(80 cm) + Carbon steel (CS) (4.3 cm) and three-layer BA(80 cm) + CS(1.4 cm) + Lead(2 cm) could be suitable options.
