Application of the FDTD-based simulation code VSTL REV to the lightning surge analysis of a nuclear power plant

Abstract The installation of effective lightning protection is necessary to protect power equipment and sensitive electronic devices and guarantee human safety in nuclear power plants. To evaluate the effectiveness of countermeasures against lightning, it is necessary to predict lightning surge phenomena. Recently, the finite-difference time-domain (FDTD) method, which is one of the full-wave numerical approaches, has been applied for analyzing electromagnetic transient phenomena in three-dimensional structures such as lightning protection systems and buildings or grounding structures such grounding grids. In this study, we model buildings and grounding structures of a nuclear power plant using the FDTD-based surge simulation code VSTL REV, and we study the effect of soil resistivities on the step voltages around the reactor building and the voltages induced on grounding buses drawn into an auxiliary building and the metal sheaths of coaxial cables in the case of a direct lightning strike to the nuclear power plant.