Development of a prototype ROV for underwater inspections in the IEA-R1 reactor pool

The IEA-R1 reactor is a pool-type reactor, being the first research reactor in Latin America, inaugurated in 1957. Its fuel is enriched uranium, and it uses water as moderator, coolant, and shielding. This reactor is installed at the Instituto de Pesquisas Energéticas e Nucleares (IPEN), and in 2002, it obtained ISO 9001 certification, designed to operate at a maximum power of 5MW. Initially, this reactor operated at 2 MW, and today it is operating between 3.5 and 4.5 MW, with the aim of producing radioisotopes, irradiating samples for various purposes, and producing radioactive sources for industry and medicine. In order to find solutions that reduce human exposure to these environments during inspections, which are becoming increasingly commonplace and complex, with the aim of ensuring the operation of systems and preventing failures, corporations and institutions have begun to invest in the development of robots to be used in nuclear power plants. The application of underwater vehicles in the industry is becoming as widespread as their use in the marine environment, and much progress has been made in the development of new technologies for the nuclear sector. According to Carminatto and Ciongoli, countries like China, South Korea, and Japan are the ones that invest the most in underwater research involving technology applications in the nuclear environment. Remotely Operated Vehicles (ROVs) are mobile, unmanned teleoperated robots used exclusively in aquatic environments, which are constantly manipulated by a pilot or operator who remains safely on the surface. The underwater vehicle is continuously connected to an operations module via a cable, called an umbilical, which allows bidirectional communication between the components submerged with the vehicle and the operator on the surface. The controller sends the necessary commands to maneuver the vehicle, which in turn, sends images to a monitor on the surface, forming an underwater visual inspection system. Visual non-destructive testing is a common practice for compliance monitoring in the industrial area, and underwater visual inspection with ROVs is one of the techniques used to monitor the conditions of submerged structures, being the only feasible method in underwater environments of nuclear power plants. The present work aims to present the preliminary results of an underwater visual inspection conducted in the pool of the IEA-R1 research nuclear reactor, using a prototype ROV developed and built by the authors. (author)