This study addresses the operational degradation of reinforced concrete structures of buildings and facilities where radioactive materials and waste are handled, if degradation is caused by the joint effect of ionizing radiation from materials (substances) handled and factors affecting the overall aging of concrete, reinforcement bars, and their combination. The research focuses on gamma radiation and its physical, chemical, and mechanical effects, triggering corrosion processes in reinforcement bars during the operation of reinforced concrete structures. Changes in the structural behavior of existing and newly built facilities, where radioactive materials and waste (with a focus on highly and moderately radioactive waste) are handled, must be predictable during the extended period of operation. Prognostication methods and assessment models must be accessible to various specialists, including design engineers. Available software packages and numerical analysis tools are used to devise these methods and models. This research project demonstrates the numerical modeling of electrochemical corrosion triggered by oxygen diffusion in concrete. The COMSOL Multiphysics software package was used to develop a model of a reinforced concrete wall segment. This model was used to analyze and prognosticate electrochemical processes in a structure during its future operation. Results of numerical modeling show that corrosion-triggered changes in the original diameter of reinforcement do not exceed tenths (11.2–12.4%) for the predicted service life of 100 years. Studies should be continued in this direction because such factors as radiolysis, carbonization, radiation heating, and changes in the aggregate can have an adverse effect on structures during their operation.
