Pienen modulaarisen reaktorin alustavan käytönaikaisen tarkastusohjelman laatiminen ja tarkastusten toteutettavuuden arviointi

The purpose of in-service inspections is to detect, assess, and monitor defects or degradation that may develop due to operational stresses, material ageing, or environmental conditions. For Steady Energy’s nuclear facility to obtain a construction license, the company must submit to STUK a conceptual plan for in-service inspections, which consists solely of in-service inspections. The main objective of this thesis was to prepare a preliminary in-service inspection program for the LDR-50 reactor and its associated piping, and to evaluate the inspectability of these components for potential structural modifications to the reactor. The study surveyed inspection equipment available on the market, focusing on devices with specified dimensions and clearance requirements. These values were compared with the free space around the reactor and piping components to determine how well the current reactor structure can be inspected using commercially available tools. The assessment of inspectability was further supported by consultation with an NDE expert. The results indicated that inspection of the current configuration with standard equipment is often challenging, as many components lack sufficient surrounding space. In addition, devices relying on magnetizing the inspection structure proved unsuitable due to the choice of materials in the reactor and piping. Expert consultation nevertheless confirmed that inspection equipment can often be adapted to the facility, or alternative methods can be selected. In conclusion, the inspectability of the reactor and its piping is at the required level to ensure that inspections can be carried out in compliance with regulations. In practice, inspection companies adapt their equipment and methods to the plant’s structures, rather than expecting the facility to be redesigned to accommodate inspection tools.