The High-Luminosity Large Hadron Collider (HL-LHC) upgrade aims to increase its luminosity by a factor of 5 beyond the LHC's design value, increasing the potential for discoveries after 2025. The increased collision rate of particles will be a challenge for the CMS systems as higher levels of radiation could degrade them and affect their performance. It is therefore important to understand the expected radiation environment and its impact on the different sub-detectors. In this study we use the FLUKA simulation package to reproduce the radiation environment during CMS Run-2 and the GEANT4 simulation package to estimate its impact on the RPC detectors. Results are compared with measurements collected by the RPC system during 2018 and reasonable agreement is observed. This study serves as a benchmark for future simulations with a Phase-2 (HL-LHC) configuration.