This work examines nuclear events resulting from the interaction of atmospheric neutrons at ground level and different atmospheric-like sources with a silicon layer. Using extensive Geant4 simulations and in-depth data analysis, this study provides a detailed comparison between several facilities and natural environment in terms of nuclear processes, secondary ion production and fragment energy distribution. The different computed databases have been used in a second part of this work to estimate the Soft-Error Rate (SER) of a widely characterized 65 nm SRAM test circuit with the Tool suIte for rAdiation Reliability Assessment (TIARA Monte-Carlo simulation code). A detailed analysis is conducted to clarify the mechanisms leading to single and multiple cell upsets and to estimate the SER of a broad spectrum source from values obtained with monoenergetic simulations.