Innovation and application of simulation and virtual commissioning technologies for the HPR1000 reactor control system

The reactor control system, the core system of a nuclear power plant, controls most of its operational processes. As the system is extremely complex, with strong coupling among control parameters, any flaws in its design could lead to abnormal operation or accidents, substantially impacting the safety and economics of the nuclear power unit. Therefore, comprehensive verification of the reactor control system design is essential. Most of the existing verification methods, such as static verification and partial simulation-based calculation verification, are single-system-type methods, leaving a substantial gap in multisystem-coupling verification. Nuclear power simulation/engineering simulators are used for debugging and verification of the reactor control system, helping evaluate control configurations and dynamic responses prior to unit commissioning, thereby reducing the risks associated with field tests.

In this study, the characteristics of the reactor control system of the HPR1000 first unit project were investigated by defining the simulation scope, identifying the interrelationships among reactor control systems, and innovatively applying advanced digital simulation technology to develop high-precision models of the control objects and the control entities themselves. These models were coupled and interconnected to design digital twin models. The features of such a reactor control system were verified by combining mechanistic models, digital computation, analytical capabilities, and new technologies, and by employing a virtual–real collaborative testing method. In addition, precise mapping of the system using a software-defined virtual space, dynamic simulation, analysis, and evaluation helped study the operating conditions of the reactor control system. Through virtual verification experiments, design flaws, potential vulnerabilities related to upstream design, and technical or manual errors were identified and corrected to optimize the reactor control system design, prevent potential accidents, and avoid significant accident losses.

Simulations and analysis under normal and transient operating conditions were performed to systematically verify the logic design and parameter settings of the reactor control system. Typical transient events in nuclear power plants were simulated and extrapolated, providing technical support for multisystem-coupling design verification while addressing the shortcomings of single-system verification. The approach was applied to the Hualong-1 project. During its application to the verification of normal system operation, transient operation, and equipment selection schemes, various design issues were identified and resolved, demonstrating the effectiveness of the approach. This application avoided unnecessary shutdowns and operational errors in the actual unit, thereby improving the safety and economic efficiency of nuclear power plant commissioning and operation and demonstrating significant value for engineering application.

The digital simulation verification platform for reactor control systems allows the flexible setting of various events, facilitating convenient analysis and identification of issues. Correct logic design, accurate interfaces, and appropriate parameter settings, adhering to the nuclear industry’s “safety first” norms, help resolve issues during the design and commissioning stages. This ensures the safe and economical operation of the nuclear power plant. Theoretical and technical references are provided on digital twin theory and technology, as well as for enterprises building and deploying digital twin systems. Based on the research findings, this study summarizes different innovative technologies and methods used in the reactor control system simulation and virtual commissioning, offering considerable reference value for the development and engineering application of complex systems in nuclear power plants.