Abstract Ignitor is an Italian designed compact Tokamak machine to demonstrate the ignition feasibility of D-T and D-D high density plasma. Peculiar problems concerning shielding, activation and material damaging due to high energy neutron irradiation and complex geometry are faced. The geometry including also toroidal configurations, the very severe requirements for personnel accessibility after operation and the insulation stringent characteristics pushed to perform a detailed analysis by MNCP Monte Carlo code. The results are crucial in the determination of the choice and the size of the shielding materials and have a strong impact on the maximum admissible duration of the irradiation, i.e. of the whole experiment.