[en] This report presents the various aspects and components of a program launched in 2010 for a significant improvement of safety of the French nuclear reactor fleet, and for an examination of the control of ageing effects and of component obsolescence with an objective of an additional 20 year lifetime extension for the exploitation of these nuclear reactors. The different aspects of the general safety approach are addressed in relationship with publications and recommendations by the main actors (ASN, IRSN, EDF, WENRA). They concern the definition of general objectives with respect to accidents (sizing operation conditions, additional domain conditions, accidents with core fusion), the assessment of the behaviour of operated reactors for relevant operating conditions which had not been taken into account at the design stage but have been taken into account in the EPR design, the search for measures to limit the radiological consequences of sizing accidents, the search for strong measures to prevent severe accidents and to limit their radiological consequences, reinforced measures to prevent fire-related and earthquake-related accidents, the adoption of a larger domain for probabilistic safety studies (EPS), the equipment toughness in case of severe accident, the improvement of exploitation conditions in terms of organisational and human factors, a closer control of materials related to the reactor cold source, the use of the 'cost-benefit safety' approach, the warehousing of fuel in deactivation pools. The next part of the report addresses the control of ageing effects and of component obsolescence: ageing control approach, methodological evolutions, fit-and-proper criteria for exploitation continuation, closer control of some specific equipment, the taking of obsolescence into account, special maintenance, non destructive controls, the maintaining of equipment qualification, the control of exploitation costs, and significant modifications of installations