The paper briefly recalls the results of previously reported numerical studies on the feasibility of protective neutron shielding of the vital parts of the Fusion Material Irradiation Facility (FMIF) Neutron Source (NS) based on the Novosibirsk Gas Dynamic Trap (GDT). The work stresses the neutronic potentialities of the facility. This mirror-type machine is designed to produce 1018D-T neutrons/s over 10 years (3×1026 neutrons). Simulations use the 3DAMC-VINIA Monte Carlo code with its drizzle-shower splitting technique and two-step cascade (bilinear functional) treatment, ENDF/B6 files, and an engineering design model that precisely reproduces critical parts of the facility. The proposed shielding ensures survival of the facility, as per project tolerances, with further shield reduction and optimization possible. Present partial shield reductions around the plasma column consent 2.5m3 of irradiation space, with 0.06m3 at 0.3×1014 thermonuclear uncollided nDT-neutrons/cm2s (0.5 MW/m2) and 0.7×1014 collided ones, axial damage gradients ⩽l%/cm over 7.8m, and ∼30 dpa in Fe-type materials at end of life.