In-service inspection of PWRs

The in-service inspection is an important part of the maintenance of PWR-type reactors. Its aim is to prevent the occurrence or development of damage using in-situ exploration means, in general non-destructive. The periodical inspection of materials is essential to check the relevance of the choices made at the design stage and to regularly check the aging of the components with time. This article presents: 1 - needs and necessity of in-service inspection: non-destructive methods, regulation, rules (French and international practices); 2 - bases and implementation of in-service inspection: first program of in-service inspection, evolutions of the in-service inspection program (regulation and experience feedback), main primary coolant circuit, main secondary coolant circuits, other circuits and systems and non-nuclear equipments; 3 - evolution of design and fabrications: impact on nondestructive controls and examinations. (J.S.)