In the decommissioning work of the Fukushima Daiichi Nuclear Power Plant, poor visibility due to dust and suspended particles is expected during the crushing of fuel debris, and a visualization method that can be used in high-dose areas with poor visibility is required. Ultrasonic-based visualization technology uses low frequencies to diffract dust and airborne particles. Since Ultrasonic probes are not sensitive to radiation, this method is expected to be useful even under high-dose conditions. In this study, we attempted to image objects using a linear array probe in both water and suspensions. In water measurements, we were able to accurately determine the position of the aluminum frame within the measured near-field range. Additionally, as the measurement distance increased, the spatial resolution of the images was decreased. Furthermore, the object images were almost equivalent both in water and in suspensions, which demonstrates that ultrasonic visualization of objects is possible even in environments with poor visibility.
Iseki et al. (Wed,) studied this question.