Introduction. The high saturation of the cable routes of nuclear and thermal stations, wind parks and solar power plants, on-board systems imposes stringent requirements in the field of fire safety of cables, which makes it necessary to use highly flame retardant halogen-free compositions. The introduction of flame retardants causes the mandatory modification (crosslinking) of the polymer matrix. Purpose. Determination of the optimal radiation dose based on the correlation between the mechanical and electrical characteristics of a radiation-modified halogen-free ethylene vinyl acetate copolymer with high-strength flame retardant insulation cables. Methodology. Mechanical and electrical tests of samples of radiation-modified cables with a copper conductor cross section of 1.0 mm2 and a halogen-free filled insulation based on an EVA copolymer with a thickness of 0.7 mm have been performed. Results. A strong correlation is established between the elongation at break and the tensile strength, between the insulation resistance and the breakdown voltage. It is shown that at the optimum value of the irradiation coefficient in the range from 7 to 5, the insulation resistance increases more than twice, and the breakdown voltage at the direct current is increased by 1.3 times. The elongation at break is within the allowed values.