The interactions of high energy neutrons produced in D-D and D-T nuclear fusion reactions with natural silicon have been investigated through direct calculation using nuclear cross section libraries, MCNP6 and Geant4 numerical simulations. We provide a detailed analysis of all interactions per type of reacting silicon isotope and an exhaustive classification of all neutron-induced secondary products. Implications for reliability of the electronics in future power fusion machines are discussed on the basis of these first evaluations.