Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) has been developed based on PFM (Probabilistic Fracture Mechanics) analyses in terms of safety, availability and economic efficiency, environmental impact and social acceptance. For the further improvement of maintenance activities, the importance of reducing human errors is often pointed out. Human errors are well recognized to be affected by mental stress conditions. Due to the amendment of Industrial Safe...
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Effects of Human Error and its Reduction Analyzed by Dr. Mainte, Integrated Simulator of Maintenance Optimization of LWRs 2

Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) has been developed based on PFM (Probabilistic Fracture Mechanics) analyses. The concept of the simulator is to provide a decision-making system 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, environmental impact and social acceptance. For the further improvement ...
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Effects of Human Error and its Reduction Analyzed by Dr. Mainte, Integrated Simulator of Maintenance Optimization of LWRs

As an attempt to apply AI in the field of maintenance, we have been developing a diagnosis method of check valves to detect the internal leakage and the signal before the leakage based on the signal analysis of their vibration measurements by a portable system with AE (Acoustic Emission) sensors. CNN (Convolutional Neural Network) was applied to the measured raw waveform and its frequency distribution corresponding to the leakage rates in order to classify the leakage rates. The leakage rate was gradually i...
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Study on the Application of AI to Check Valve Diagnosis

We have developed Check Valve Inspection System using acoustic emission sensor and ultrasonic sensor, to examine degradation and detailed motion (Full open, Tapping, Oscillation, etc.) of the swing check valve. This inspection system was applied check valves in the seawater system line of domestic nuclear power plants. The examination was carried out before and after replacing the check valve. Comparing the results of the inspection system and the results of overhaul, effectiveness of this system has b...
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Development of check valve inspection technique

The purpose of this research is development of tension measurement method using hammering sound diagnosis technology using Acoustic Emission sensor. Experiments using actual size anchors and FEM analysis quantitatively evaluated the relationship between the vibration characteristics of the anchor head and the tension introduced into the anchor. As a result, it is possible to evaluate the anchor tension based on the natural vibration characteristics of the anchor head. ...
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Evaluation of tension of ground anchor by hammering test using AE sensor Vol.1

The purpose of this research is development of tension measurement method using diagnostic technique of hammer sound using acoustic radiation sensor. This report summarizes the method of evaluating the anchor tension based on the natural frequency of the anchor head and the applicability of the method to measured data at the site....
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Evaluation of tension of ground anchor by hammering test using AE sensor Vol.2