During the past 20 years many works have been done on Ageing Management Program (AMP) of Safety classed components in EDF.
To-day, EDF is starting the 3rd ten-year shutdown of all these 3-loop plants (34 plants). During the associated Safety Review, a specific task is devoted to ageing effects and management of all the safety concerned components. A large list of components has been reviewed: mechanical, civil engineering, instrumentation and control, cables, non metallic components.
Cast duplex stainless steel components are an example of these reviews. This material is used in many PWR components: elbows, pump casing, valves…A specific Ageing Management Program has been developed in France in the past 20 years in order to consider thermal ageing consequences on different components.
This program considers:
- Degradation mechanism understanding;
- Diagnostic: what are the more sensitive components;
- Monitoring in operation: thermal power;
- In-service inspection: radiography and other laboratory methods;
- Flaw evaluation and material properties;
- Replacement of elbows, alone or associated to steam generator replacement.
The paper will give a short description of each topic. In the moment EDF is planning a large replacement program of CF8M elbows to assure safety margins for 60 years of operation.