Open Phase Condition Scenarios for Nuclear Power Plant Electrical Network Studies

Open phase condition (OPC) is a situation where one or two phases of the feeding network are disconnected and the voltages become unbalanced. In a nuclear power plant (NPP), OPC can be a source of common cause failure and needs to be, therefore, carefully analyzed. There have been events where NPP safety has been compromised because the OPC has not been detected properly by plant protection and safety critical components have been disconnected by their own protection. This paper describes the scenarios that need to be studied to ensure safe operation of NPPs also when an OPC occurs.