This is the proceedings of an international conference focusing on status and trends in the development of water cooled reactors in the 21st century. The main objectives of the meeting were to promote exchange of information among experts from Member States and representatives from operating organizations. The range of subjects discussed by the conference participants and high level keynote speakers covered the challenges and opportunities encountered when starting and/or expanding a nuclear power programme, very specific solutions for reactor pressure vessel integrity, material degradation, ageing management and non-destructive examination methods, as well as advanced water cooled reactor technologies and their innovative applications. More than 260 participants from 54 Member States and four international organizations took part in this event, and a total of 133 papers were presented.