Ultrasonic visualization technique for spatial recognition in highly radiated environments with poor visibility(Contract research); FY2024 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Osaka*

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), has been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") from FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2024, this report summarizes the research results of the "Ultrasonic visualization technique for spatial recognition in highly radiated environments with poor visibility" conducted in FY2024. The objective of this research project is to establish a visualization technique using ultrasonic phased array (hereinafter referred to as PA) as a technique that enables spatial recognition in poor visibility and highly radiated environments that are expected during the removal of fuel debris in the decommissioning of 1F. The project aims to develop a visualization technique for object shapes both in the air and in the water, and each research group will conduct the following projects: (1) Visualization of object shapes in the air and in the water by ultrasonic PA measurement (The University of Osaka), (2) Development of airborne ultrasonic PA device (Nihon University), (3) Visualization in particle suspended environment by high frame rate PA (Tohoku University), and (4) Development of ultrasonic measurement methods for high intensity gamma-ray environments (The University of Osaka).