Development of a Submersible Robot (ROV) to support visual inspection in triga type research nuclear reactors

A remotely controlled submersible robot (ROV) was developed for visual inspection of submerged equipment and pipelines, including submerged nuclear reactors and depleted fuel element storage pools. ROVs are unmanned vehicles operated remotely by a person that allow the operator to remain in a comfortable environment while the ROV works in unhealthy environments. The equipment was manufactured with components of reduced monetary value and additive manufacturing. The ROVs will feature AISI 403 stainless steel shielding to protect against gamma radiation, allowing access to places with ionizing radiation. However, the focus is only on radiological protection against gamma radiation, despite the presence of neutrons from fission. In submerged nuclear reactors. All reactors have control rods that capture neutrons, slowing the reaction and minimizing neutron emission. The IPR-R1 Triga reactor, which first became critical 60 years ago, requires regular visual inspections due to the natural aging of its fuel elements. These inspections are necessary to detect signs of wear, such as stains and corrosion spots, which can be mitigated through an aging management plan. The aging plan was developed such a plan based on recommendations from the International Atomic Energy Agency (IAEA), which includes visual inspections every two years. It is therefore justified to use visual inspection devices to promote the detection of possible corrosion points. The Gamma Irradiation Laboratory (LIG), located on the CDTN premises is classified as a Category II Multipurpose Panoramic Irradiator, manufactured by MDS Nordion in Canada, Model/serial number IR-214 and type GB-127, equipped with a Cobalt-60 source dry storage with maximum activity of 2,200 TBq or 60,000 Ci. ROV tests were carried out under gamma ionizing radiation, on the LIG premises, at different dose rates in order to measure the resistance of the ROV circuit to radiation. (author)