Researchers Developed Simplified Microreactor Model
Researchers at the College of Engineering at the University of Michigan have developed a simplified microreactor model that preserves key parameters such as specific electric power, inlet coolant temperature, core pressure, and flow rate. This study is based on the Holos-Quad (Gen 2+) model, a high-temperature gas-cooled reactor (HTGR) type microreactor.
They leveraged model predictive control (MPC), a method that predicts future behavior to optimize control over a defined period of time under certain constraints. Specifically, they developed an MPC controller that optimized the rotation of control drums that surround the microreactor’s central core that decrease power when facing inwards and increase power when facing outwards.
To ensure the model was based in reality and accurately representing the microreactor’s operation, the researchers integrated PROTEUS, a simulation toolset for high-fidelity reactor physics analysis
When tasked with ramping the power up or down at 20% per minute, their control algorithm stayed within 0.234% of the target. It does all of this without AI, meaning everything about the automated control for load follow operation is grounded in physics and mathematics and readily explainable—an essential feature for passing regulatory review.
Extensive sensitivity testing confirmed that the MPC controller operates effectively over a wide range of model input parameters, demonstrating the feasibility of autonomous control.
The new algorithm will help manufacturers design reactors with autonomous control systems that are safer and more reliable, while automatically calculating and implementing adjustments to regulate power.