Robotic Replacement of Spent Nuclear Fuel Rods

This paper details the design and development of a robotic system for the autonomous replacement of spent nuclear fuel rods, focusing on the integration of mechanical design, control systems, and sensor-based navigation. The robot utilizes a four-bar linkage grabber mechanism for precise fuel rod manipulation and a line-following circuit with light sensors and bump switches to autonomously navigate the reactor environment.

The methodology includes kinematic and torque analysis to optimize the grabbing mechanism and motor selection, ensuring the robot can reliably remove spent rods and insert fresh ones. A PID-controlled Pololu motor enhances the accuracy of the grabber’s motion. The V-shaped guide at the robot’s front aids in precise alignment with reactor tubes, improving rod retrieval and insertion. The system employs state-machine programming and non-blocking code to manage complex tasks efficiently.

Experimental results demonstrate the robot’s ability to complete the fuel rod replacement process, though challenges in line-following accuracy and motor torque limitations affected performance. The study highlights the importance of precise mechanical design, sensor calibration, and control algorithms in nuclear automation, showcasing how robotics can enhance safety and efficiency in hazardous environments.