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
Development of an underwater robot for nuclear reactor vessel
In this paper, an underwater robot for inspecting and maintaining nuclear reactor vessel is developed. Based on the kinematics analysis of the robot, the workspace is obtained. In order to evaluate the influence of water environment to the robot, the hydrodynamic forces including water resistance and additional mass force are analyzed. Then some experiments including watertight test are performed to evaluate the performance of the robot and simulations are carried out to verify the theoretical analysis. The experimental and simulation results show that the developed underwater robot which can work at 22m in water meets the design objective basically and the analyses on kinematics and hydrodynamic forces are reasonable.
Cooperative mutation based evolutionary programming for continuous function optimization
In this letter an evolutionary programming (EP) algorithm adapting a new mutation operator is presented. Unlike most previous EPs, in which each individual is mutated on its own, each individual in the proposed algorithm is mutated in cooperation with the other individuals. This not only enhances convergence speed but also gives more chance to escape from local minima.