Ultrasonic imaging techniques for non-destructive testing of nuclear reactors, cooled by liquid metals: review

In some nuclear reactors the core is cooled by means of liquid metal alloy, for example, lead-bismuth eutectic alloy. For safety and licensing reasons, an imaging method for evaluation of status of the interior of reactor has thus to be developed. There are no any other physical means except ultrasonic, which would enable to inspect inner reactor parts submerged in the opaque hot liquid metal. The operating conditions significantly restrict the possible architecture of the visualization system and materials, which can be used On the other hand, the system should be ‘simple’ enough to enable implementation of it in above mentioned conditions. The paper is devoted to review of ultrasonic imaging techniques, suitable for use in the opaque hot liquid metal alloy. Also several modeling approaches, which could be used for acoustic modeling of the reactors, are reviewed here also.