Lightning Surge Analysis of a PWR Nuclear Power Plant Using the Three-Dimensional FDTD Method

Lightning protection is an important factor in the design of nuclear power plants, for example, to protect power equipment and sensitive electronic devices and guarantee human safety. To design effective protection measures, it is useful to predict lightning surge phenomena and evaluate the effectiveness of the protection measures. Recently, the finite-difference time-domain (FDTD) method, which solves Maxwell's equations directly and does not require the assumption of a transverse electromagnetic mode, has been an effective tool for analyzing electromagnetic transient phenomena in three-dimensional or grounding structures. In this study, we model buildings and groundings of a nuclear power plant using an FDTD-based surge simulation code, study the ground potential rises of a nuclear power plant, step voltages around the reactor building, and the transient responses of grounding buses drawn into the auxiliary building and the metal sheaths of coaxial cables in the case of a direct lightning strike to the lightning protection system (LPS) of the reactor or turbine building, and study the effect of the configuration of the LPS.