This paper describes the methodology of the French surveillance program as well as some aspects of the experience gained during its progress. Its main uses in the structural integrity assessment of the vessel consist of updating and validating the conservatism of the prediction of the lower-bound toughness curve used to assess the margins against brittle fracture. Its perspectives in the frame of the planned extended operation beyond 40 years are associated with the flux reductions that will be implemented in the 900-MWe fleet. Two surveillance capsules are dedicated to a specific monitoring in the 40 to 60-year range to complement the data set in the relevant fluence range.