Comparative analysis and countermeasures of power system open phase conditions in Korea’s standard nuclear power plants

•The Open Phase Condition (OPC) is defined as an open circuit of one or two of the three phases of any power circuit needed for the normal operation of electrical systems.•The OPC of the nuclear power plant (NPP) may cause station blackout (SBO) and pose a great risk to the integrity of the reactor core.•It was confirmed that there was a valid difference in OPC detection between the types of Korea’s standard NPPs.•The goal of this study is to secure the integrity of the reactor core by detecting the OPC of the NPP’s power system early.