Recent experiences using AIRIS as a platform for phased array ultrasonic and remote visual inspections

Doosan Babcock has recently gained experience of using underwater robots to provide compact, simple and versatile platforms for deploying inspection equipment within reactor pressure vessels (RPVs). Their small size and low profile make them ideal for inspecting areas with restricted and difficult access. Their simple lightweight design make them easy to deploy and operate with minimal reliance on the main crane or refuelling bridge; this removes inspections from the critical path of a station outage. AIRIS (Advanced Inspection of Reactor pressure vessel and Internals System) is a family of underwater robotic crawlers, each targeted at different areas within the RPV of light water reactors. Although developed to access difficult areas such as core shrouds, these robots will provide the platform for tools and inspection equipment for many other underwater components and structures. The scanning arm on AIRIS, designed for use with ultrasonic probes, has been adapted in-house to allow video cameras and LED lights to be carried for visual inspection. Trials at MPA Stuttgart demonstrated the ability of the automatic navigation systems and the clarity, detail and stability of the recorded images. Trials with a phased array ultrasonic system established its positioning accuracy and repeatability, its manoeuvrability in restricted spaces, and the capabilities of the phased array system.