Coordinated control of the World's first multi-modular high temperature gas-cooled reactor power plant HTR-PM

The modular high temperature gas-cooled reactor (mHTGR) adopts helium as coolant, graphite as moderator and structural material, and TRISO particle-based fuel elements. The HTR-PM is the world's first multi-modular high temperature gas-cooled reactor power plant, having successfully entered to its commercial operation. To ensure inherent safety, the two reactors of HTR-PM are designed with the features of low power density, strong negative temperature feedback and large surface-to-volume ratio, giving a rated reactor thermal power of 200MWt. To enlarge plant power rating, the scheme of two reactor modules driving a common steam turbine is deployed. Since the modules are coupled by the turbine, the coordinated control is key in providing a stable and efficient operation. In this paper, the design of implementing coordinated control laws on distributed control system (DCS) is given. Then, the response of key process variables under power step conditions is analyzed This work manifest the feasibility of multi-modular nuclear power plant (NPP) scheme for the first time, showing the promising future in building large-scale NPPs by small modular reactors (SMRs).