Project:
As part of DOE’s Advanced Small Modular Reactor (AdvSMR) R&D program, the Supervisory Control of Multi-Modular Advanced Reactor Plants project was established to create innovative control strategies and methods primarily to address operations and maintenance (O&M) costs in AdvSMRs.
Although supervisory control and data acquisition systems are commonly used in industry, they perform tasks from a limited set of automation rules, and cannot accomplish complex tasks that require situation analysis, or arrive at a decision and execute that decision in the presence of a disturbance or in the event of deviation from a nominal plant state.
ORNL’s risk-informed, performance-based supervisory control system (SCS) achieves near autonomy through incorporation of controls, diagnostics, and decision-making within a hierarchical functional architecture based on actual plant status in real time. Unlike conventional control systems, the SCS accounts for:
- any combinations of current and projected status of critical plant equipment in real time,
- a probabilistic description of the current and projected status of equipment,
- for alternative control actions, the ability to project the dynamic plant behavior, including permutations of occurrences and timing of equipment failures, and
- a re-ranking of control options based on component health.
Benefit:
Within the SCS, the probabilistic assessment provides a ranking of viable control actions based on actual plant status, including equipment failures; however, certain instructions generated by the probabilistic model only include an abstract notion of action without specifications. The performance-based system models assess and rank each of the probabilistically identified control actions by taking into account the physical behavior (current and projected) of the system. A utility theory algorithm factors into the decision making by estimating the distance from and approach to a trip setpoint for each control option, including how rapidly the system approaches the trip setpoint. The SCS then generates a single solution, sends a signal to the necessary actuators and equipment, and informs the operator of action taken.
Some benefits of an SCS approach that are expected based on this study include:
- reduced operator work load,
- potential reduction in O&M costs through monitoring of a component’s health and using a predictive approach to scheduling plant maintenance,
- design and performance optimization through application of traditional risk techniques to the consideration of the operational performance risk of the plant, and increased plant availability, reliability, and safety.
Sponsor:
DOE Office of Nuclear Energy, Advanced Reactor Technologies
Principal Investigators:
Sacit M. Cetiner, Mike Muhlheim
