Development of a Tele-operated Underwater Robotic System for maintaining a light-water type power reactor
The safety and reliability of nuclear power plants is very important. An inspection and maintenance of nuclear power plants should be achieved simultaneously. However, the limitation of a radiation exposure makes it difficult to work in nuclear power plants. Therefore, a tele-operated robotic system is very useful for inspecting and maintaining the components of nuclear power plants because it reduces the level of a radiation exposure to the human operators and it improves the reliability of an operation. A tele-operated underwater robotic system is needed for detecting and removing a loose part in a nuclear reactor vessel. A loose part, which can come from any failed component or an item left during a construction, refueling or maintenance like metallic parts, bolts, nuts and washers, affects the safety of a nuclear power plant. In this paper, an underwater robotic system is developed for inspecting the bottom of a nuclear reactor vessel and a reactor coolant system and also for removing some particles in them. In order to evaluate the performance of the developed underwater robotic system, an experiment was performed in a small swimming tank. In the experiments, the developed robotic system could inspect the state of the tank and remove some particles successfully
A new approach for crack detection and sizing in nuclear reactor cores
Abstract Remote Visual Inspection (RVI) of reactors in nuclear power plants allows station operators to assess the health and condition of their plant. In the UK, most nuclear stations are of the Advanced Gas-cooled Reactor (AGR) design. During planned periodic outages, a representative portion of each AGR core is inspected using specialist tools equipped with various sensors including a video camera for RVI. If cracks are observed in the core during data capture, a stitched image of the region needs to be created so that the crack can be analysed and sentenced (classifying the crack morphology, location, orientation and size) before the station is returned to service, provided return to service is justified. Currently, the crack analysis and sizing activities are conducted manually by expert analysts in a laborious process. In this paper, we present a new image processing approach capable of automating aspects of the crack analysis process. Specifically, we describe a set of techniques for quickly and accurately detecting the presence of cracks in AGR fuel channel inspection images. We also present a method for detecting circular channel features known as trepanned holes whose dimensions are known and can thus be used for scaling. The results of applying the proposed techniques are evaluated on image data from real AGR fuel channels and are shown to produce comparable results to those obtained manually. The advantage of the proposed approach is that it is fast, robust and more repeatable than the existing manual approach.
Research on Control and Planning of Soft-Wing UAV for Haze Removal
The existence of fog and haze has caused great pollution to the environment. The research of removing haze is a hot topic in recent years. In this paper, a special haze removal algorithm based on Soft- Wing UAVis proposed. In this algorithm, two track control strategies are designed based on the Soft-Wing UAV model transfer function. A SIMULINK platform based mathematical model of Soft-Wing UAV is built to testified effectiveness of the two track control strategies. An autonomous ergodic-planning algorithm with greedy strategy and foldback algorithm for Soft-Wing UAV is designed. Within the algorithm, the haze regional has been modelled, the cost matrix is constructed, and the planning and ergodic strategy is proposed. Finally, the experimental results validates the reliability of the algorithm in the application of haze removal with the proposed evaluation Index.