[en] Flat samples of semicrystal copper and aluminium were subjected to creep tests in the WWR-K reactor experimental channel with 1.4x10¹⁶ s^-1xm^-2 neutron flux density. Copper samples were tested at temperatures of 423-773 K and 20-69 MPa stresses (aluminium at 333-473 K, 9.8-24.5 MPa). Reactor and temperature creep rate dependence for copper and aluminium at a steady stage under different test conditions were determined. Three areas with different inclination and energy activation were observed on this dependence curve. Energy activation of copper reactor and thermal creep is constant in one area and changes by transition into another one. Reactor creep energy activation at a temperature of T≤0.4T_melt is significantly less as compared to thermal one