A critical step in the development of a tokamak reactor design systems code incorporating the environmental and safety (E&S) features is the capability to calculate the neutron activation radioactivity in a fast and efficient way in order to couple with other physics and engineering modules. We have generated a numerical neutronics database in order to perform the formulation of empirical scaling laws for the radioactivity inventory in various materials. We have studied the activation of the silicon carbide (SiC) composite as the first wall of a fusion reactor. Its radioactive inventory can be calculated approximately by a simple scaling equation.