By providing the necessary scientific expertise and support to the authorities, the regulators and the public, technical and scientific support organizations (TSOs) play an important role in developing and maintaining nuclear safety and security systems in States. This conference, held in Tokyo as a follow-up of the 2007 TSO conference, focused on international cooperation and networking among TSOs to enhance nuclear safety and security, especially in terms of their role in the regulatory framework, including capacity building in those countries considering embarking on nuclear power programmes. The conference objectives were to develop a common understanding of the responsibilities, needs and opportunities of TSOs, and to further promote international cooperation and networking among them. These proceedings include a summary, the opening speeches, the invited papers, and the conclusions and summary of the conference by the President. The accompanying CD-ROM contains the unedited papers contributed, the presentations that were submitted with some of the invited papers and papers exhibited at the poster session.