Reconstructing Fukushima: A Case Study

We present the application of 3D reconstruction technology to the inspection and decommissioning work at the damaged Fukushima Daiichi nuclear power station in Japan. We discuss the challenges of this project, such as the difficult image capture conditions (including under water), required use of limited imaging hardware, and capture by personnel inexperienced in 3D reconstruction. We present an overview of the system developed for this project, a real-time reconstruction pipeline with robust camera pose estimation, low-latency probabilistic dense depth estimation and a novel descriptor for point cloud alignment - the Co-occurrence Histogram of Angle and Distance (CHAD). We discuss the modifications required to standard algorithms in order to perform reliably in such a scenario. As well as quantitative evaluations of these components on existing datasets, we show qualitative 3D reconstruction results of debris from the damaged plant and its spent fuel pool. Such results have enabled planning of the critical process of debris removal, without the harmful requirement of extensive human presence on site.