Development of a Supervisory Control system concept for advanced small modular reactors

Small modular reactors (SMRs) can provide the United States with a safe, sustainable, and carbon-neutral energy source. Because of their small size and, in many cases, simplified nuclear island configurations, it is expected that capital costs will be less for SMRs compared to that of large, Generation III+ light-water reactors. Advanced SMRs (AdvSMRs), which use coolants other than water as the primary heat transport medium, introduce several passive safety concepts and controls features that further reduce the complexity of primary system designs by eliminating redundant components and systems. Under U.S. Department of Energy (DOE) Office of Nuclear Energy (NE), the Supervisory Control of Multi- Modular SMR Plants project was established to enable innovative control strategies and methods to supervise multiunit plants, accommodate shared systems, identify opportunities to increase the level of automation, define economic metrics based on the relationship between control and staffing levels, and permit flexible co-generation operational regimes. This paper documents current findings from the Supervisory Control project. Specifically, it defines and documents strategies, functional elements, and an architectural structure for supervisory control of a representative generic AdvSMR plant. More specifically, this research advances the state-of-the art by incorporating decision making into the supervisory control system architectural layers through the introduction of tiered taxonomy of plant systems and subsystems. The proposed architecture has the features of planning and scheduling, analyzing plant status, diagnosing problems as they develop and predicting potential future problems, making decisions based on these features, and generating validated commands to lower control layers in the architecture.