Mitsubishi Unveils Underwater Robot for Nuclear Reactor Inspections

Mitsubishi Heavy Industries has introduced a cutting-edge underwater navigation robot designed for non-destructive inspections of nuclear reactor vessels in Japan. This innovative machine, named the A-UT Machine, is engineered to operate in high-radiation environments, ensuring safety and efficiency during inspections.

The A-UT Machine measures 1.8 metres in length, 1 metre in width, and 0.9 metres in height. With a weight of 400 kilograms that effectively becomes zero when submerged, it is equipped with thrusters and wheels that facilitate movement along wall surfaces. The robot performs weld-line inspections using a sophisticated manipulator arm, which features a seven-axis design capable of carrying loads up to 10 kilograms with an impressive positioning precision of ±0.1 millimetres.

Advanced Features for Enhanced Efficiency

The A-UT Machine can operate at depths of up to 20 metres. Its position is tracked in real-time using a target mounted on the robot, employing triangulation methods to ensure accurate orientation. When two units operate simultaneously, the time required for inspections is significantly reduced, enhancing overall operational efficiency.

Control of the A-UT Machine is facilitated remotely via a desktop computer and joystick, which allows for precise maneuvering in complex underwater environments. Since its introduction to pressurized water reactor (PWR) plants in Japan in 1995, there have been 46 deployments recorded, demonstrating its reliability and effectiveness in critical inspection tasks.

Mitsubishi developers have noted that the unit has been certified as the #1 Maintenance Heritage by the Japan Society of Maintenology. This designation recognizes the machine not only for its technological significance but also as part of the cultural heritage related to maintenance technology.

The A-UT Machine represents a significant advancement in nuclear safety and maintenance practices, showcasing Mitsubishi’s commitment to innovation in the field of robotics and automation within high-risk environments.