[en] Although operating skills of domestic nuclear power plants are improved and various efforts are being made to prevent the unexpected reactor scram, the plant trip due to SPV (Single Point Vulnerability) still occurs. Unplanned plant trip leads to the generation loss which means economic loss and this is why the detailed review, systematic risk evaluation and countermeasure establishment on the SPV of the plant are needed in the domestic Nuclear Power Plants (NPPs). In the same manner, U.S. nuclear industry makes an effort to remove the SPV of their plants. For example, Arkansas Nuclear One made a list of SPV whose failure results in plant transient including de-rate or reactor scram and corrected the difference between lists for the unit 1 and 2 through the cross check of the expert group which is called Unit Reliability Team. Shearon Harris is also one of the utilities which organized the task force to resolve SPV problems and they focused on the major 4 systems which resulted in plant trip during recent 14 years. Exelon identified SPV components through the review of MR (Maintenance Rule) functions and DC Cook performed the detailed fault tree modeling of the plant BOP system. Recently, KHNP encourages their plants to make an effort to drive the plan which could reinforce the control of SPV components. The plants have developed their SPV lists to establish further actions and NETEC (Nuclear Engineering and Technology Institute), which is responsible for an engineering part as a subsidiary of KHNP, is performing the verification of the SPV lists and FMEA (Failure Mode Effect Analysis) and fault tree modeling of major systems related with plant transient