Service life management system of concrete structures in nuclear power plants

The Service Life Management System (SLMS) is a tool for predicting the condition of structures over a long design period, planning and organising all interventions related to the upkeep of structures and evaluating the costs and environmental impacts of interventions over the design period. The interventions include maintenance and repairs and in special cases rehabilitation and renewal. The inspection of structures and the upkeep of a database are interlinked with the SLMS. A life cycle cost (LCC) analysis, including annual costs, and a life cycle assessment (LCA) are performed for the whole design period. Other features such as structural analyses, qualitative and quantitative risk analyses, and MADA (Multiple Attribute Decision making Aids) can also be added to the system. The system characterizes the utility of a plant with the following information: present condition state of structures, predicted condition of structures over the licensed operating time, predicted service life of structures, predicted maintenance and repairs and their timings during the whole operating time, and the costs of maintenance and repairs. Using the SLMS, the administration of a NPP can convince and persuade authorities that the concrete structures in the NPP fulfil all the requirements of performance and safety. The upkeep of structures can be designed in a way that the requirements will be fulfilled during the licensed operating time. For maintenance staff and designers, the SLMS specifies and schedules all the maintenance and repairs throughout the operating time so that they can be systematically taken into account in the annual action and resource plans.