Maintenance Optimization of LWRs Based on PFM Analysis

We have been developing an integrated simulator for the maintenance optimization of LWRs (Light Water Reactors) based on PFM (Probabilistic Fracture Mechanics). As a typical example of the analysis, .an attempt was made to develop an economic evaluation model for the purpose of optimizing the maintenance activities of SG tubes in PWRs based on PFM approach, In the model, the probabilities of these risks were evaluated first and then the risk-benefit analysis was carried out to evaluate costs and profits as well during 60 years lifetime under various maintenance strategies. The model would be applied to pipes which are critical in terms of safety, availability and economy. The concept of the simulator is to provide a method to optimize maintenance activities for representative components and piping systems in nuclear power plants totally and quantitatively in terms of safety, availability and economic efficiency (both from cost and profit). The simulator will also provide a guideline regarding social acceptance of risk-based decision makings. This study has been conducted under “Innovative and Viable Nuclear Energy Technology (IVNET) Development Project” financially supported by Japanese METI.