The Lungmen Nuclear Power Project (LMNPP) with 1350 MWe twin units is the first advanced boiling water reactor (ABWR) project owned by the Taipower Company in Taiwan. Video display units are the main human-system interface for operators to manipulate, i.e., so-called "soft" control, and to know the status of the equipment and plant information. Several concerns arise when compared to hard controls. These concerns led us to conduct an investigation of the operator's performance and the potential issues regarding the operator's teamwork. The results of the investigation show that the most important task is to establish an intensive training program that addresses the knowledge and skill requirements of the operators to meet the task characteristics and the responses of the plant processes.