An ultrasonic testing device uses a scanner, employing an ultrasonic probe for scanning, to ultrasonically test a desired tested range of a subject, and includes: an information acquirer to acquire data on the subject, the scanner, the ultrasonic probe, and testing conditions; an interference analyzer to use the data acquired by the information acquirer to calculate one or more interference ranges between the subject, having one or more interferers, and the scanner, having the ultrasonic probe attached thereto, and a scan path planner to use the one or more interference ranges to calculate a scan path of the ultrasonic probe, based on the acquired data on the testing conditions, so as to avoid the one or more interference ranges.

A method for assisting with surveillance of an element of a nuclear reactor, said method being implemented by an electronic device, comprising the steps of training an artificial-intelligence algorithm; acquiring an image of the element; estimating, on the basis of the image and via the artificial-intelligence algorithm, whether a fault is present in the element; displaying the image of the element; and if at least one fault is estimated to be present, generating an alarm. In the estimating step, an input to the artificial-intelligence algorithm is an image of a region comprising the element, and an output is a level of confidence as regards an absence of fault in the element for said region. If the level of confidence is lower than a threshold, then a fault is estimated to be present. In the training step, only images of fault-free elements are inputted into the artificial-intelligence algorithm.