Verification And Validation Studies Of Nuclear Power Plant's Digital Control System (dcs)

As computer, control and communication (3C) technology develop continuously and rapidly, combined with the user requirements of advanced control and management function keep increasing during the last two decades, digital control system (DCS) began full access to the practical application of nuclear power stations. Tianwan Nuclear Power Plant (NPP) is China's first user of digital control system, promoting that Chinese NPP translate from the traditional analog control to all-digital control system and advanced Manual Control Room (MCR) technology; LinAo NPP phase II's major technological improvements-DCS system, designing the digital control system, constructing and commissioning independently for the first time, is one of the most important technological innovations. LinAo phase II's DCS can provide precious reference and experience for the DCS construction of other CPR1000 series'NPP.In the self-based DCS system commissioning process, it is necessary to develop simulation platform for the control system for the verification and validation (V&V) of nuclear island and the conventional island control system. The simulation V&V platform, connected with the actual DCS of NPP can play important role during early testing or on-site commissioning of DCS, carry out initial single-step or online testing, logic previews and qualitative analysis.Based on the urgent testing need of CPR1000 series'DCS, referring to LinAo NPP phase II's Manual and associated control systems'analog and logic diagram of control principle, control system parameter set-point manual and so on, we design and develop the simulation V&V platform of DCS.The simulation tests were performed on the modular structure of the thermal-hydraulic calculation and analysis procedures, control and protection system function simulation program, data collection procedures, Graphical User Interface (GUI) model in the control-station simulation integrated platform, and the establishment of data server to achieve data communications. This paper describes the functional module's development process and supporting technology of the simulation V&V platform in detail; Finally we apply the platform to DCS's closed-loop testing and open-loop testing, including step down load transient conditions and the linear load rejection to 15% FP transient conditions。By comparing the simulation V&V platform's calculations, LinAo NPP phase II's test results, as well as a running experimental results of LinAo NPP phase I, we found that the stable trend of all the parameters and the time to reach a new steady state are basically the same. The simulation V&V platform realized V&V of control configuration and parameter set-point at the scene of the early commissioning of DCS, improved the efficiency of the DCS commissioning, cost savings, and reduced risk. This technology has a complete software platform for architecture and hardware and software communication, for other nuclear power plant control and protection system's early testing or on-site commissioning is also a good value.