The study evaluates neutron spectra in the temporary control rooms of the NICA Accelerator Complex at JINR using Geant4 Monte Carlo simulations. A detailed geometric model of the accelerator hall and control rooms was developed, incorporating shielding walls and labyrinth paths. A custom CAD-to-Geant4 converter was developed to ensure accurate 3D model import. Simulations, run on the JINR “Govorun” supercomputer, involved two stages: neutron spectra generation from ion beam-collimator interactions and subsequent spectra assessment in control rooms. Results of the study estimated the neutron spectra and showed the presence of high-energy neutrons.The two-stage approach and high-performance computing enabled efficient particletransport simulation, while the geometry converter provides a valuable tool for future radiation protection studies.