[en] The authors comment the current national (United States) and international techniques, experience and problems in the field of pre-service and in-service inspection of pressure vessels and piping of nuclear power plant reactors. They also comment the personnel qualification issue, and results obtained during inspections of components of various nuclear plant reactor vessel (BWR and PWR). They highlight and comment the major problems associated with in-service inspection: the scarcity of personnel trained and qualified for reactor system examination, the variability of procedures and data recording, and the problem of inspection personnel radiation exposure