Innovation has been a driving force in the successful deployment of nuclear energy and remains essential today for its sustainable future. As nuclear energy is an attractive option for ensuring diversity and security of energy supply, as well as lower global climate change risks, the way to continue this innovation is a key issue for industry and interested governments. This report provides an overview of the state of the art in nuclear innovation systems, including their driving forces, main actors, institutional and legal frameworks, and infrastructure for knowledge and programme management. It also offers policy recommendations based on country reports and case studies supplied by participating member countries.