Functional modeling for operating procedure tasks of a Chemical and Volume Control System in PWR

Most of operator tasks in the nuclear power plants (NPPs) are performed by following a set of prescribed procedures, where human errors might occur in any phase of procedure. With the introduction of more operational information and automation into the main control rooms by digital technologies, operators are becoming easier to lose their position perception in the procedures and situation awareness when they execute operations. By employing Multilevel Flow Modeling (MFM), a strategy is presented for improving situation awareness and information sharing among operators when they implement operating procedures. Taking the Chemical and Volume Control System (CVCS) in PWR as an example, the procedure tasks of restoring CVCS operation from malfunctions are analyzed firstly, and then MFM models of CVCS in different task phases are presented. Finally, the potential applications are discussed of the proposed technology for emergency operating procedures management, human influence analysis and system reliability monitoring. (author)