Non-Nuclear Advanced Controls Testbed

Microreactor applications such as terrestrial remote deployment and nuclear thermal propulsion require remote access for autonomous monitoring and control. However, even with the fastest available communication technology, there remains a nontrivial risk of delays between the issuance of a command by the remote control system and the local actuator response needed to mechanically operate the reactor safely and reliably. Oak Ridge National Laboratory has developed a non-nuclear hardware-in-the-loop testbed to demonstrate and validate autonomous control algorithms and elements. The system design is modular, and its hardware (e.g., motors and sensors) is interchangeable, so the user can reconfigure the system for each test case. The testbed includes six hollow control drums inserted around the periphery of a mock-up reactor core. These drums can be filled with various materials to change their weights, resulting in changes to torque and friction in the drive mechanism. Output from sensors throughout the testbed relay system status and hardware response to the user control algorithm, including measurements of temperature, flow, pressure of a loop, control drum position, and drum speed. These data inform a microreactor neutronics model, which in turn uses the physical measurements as inputs to simulate reactivity feedback. The neutronics model data and sensor outputs are then fed back to the user control algorithm to complete the control loop to respond to the expected changes in reactor power. The testbed is designed to accurately represent similar real-world systems and to characterize control algorithms in fault and accident scenarios by physically faulting different sensors or control mechanisms in the testbed. This testbed will allow users and contractors to test and certify their control algorithms and instrumentation for eventual adoption as a part of the instrumentation and control of a microreactor.