Experience in unattended monitoring systems applied to PHWR reactors in Argentina– Progress Achieved

The progress achieved with the unattended monitoring safeguards systems (UMS) applied for verification of spent fuel transfers in PHWR nuclear power plants in Argentina is described. The safeguards verification activities to cover the spent fuel transfers between two nuclear reactors in Atucha complex have been done using a mobile system based on neutron detectors and surveillance applied to the various stages of the transfer process. These systems are verified during the routine inspections at these facilities. For this verification a specific joint procedure IAEA/ABACC has been successfully applied over the last year. Another UMS project has been tested for a long period at Embalse nuclear power reactor. This system covers the spent fuel transfers from the pond to the dry storage site. This UMS is a more complex system based on different types of detectors, containment and surveillance means and its application is combined with unannounced inspections (UIs). The main components of these systems and the results achieved are presented. The expectations for the future in terms of safeguards efficiency and effectiveness are discussed. The field trials and the continuous cooperation with the Argentinean Nuclear Regulatory Authority (ARN) and the Facility Operators have been fundamental for the successful development and implementation of the UMS concept under the framework of the ABACCIAEA joint use of equipment and technologies.