[en] The MDEP is a unique ten-nation initiative being undertaken by national regulatory authorities from Canada, China, Finland, France, Japan, Republic of Korea, the Russian Federation, South Africa, the United Kingdom, and the United States with the purposes of co-operating on safety design reviews of new reactors and identifying opportunities to harmonise and converge on safety licensing review practices and requirements. The OECD Nuclear Energy Agency has been chosen to provide the technical secretariat support. The International Atomic Energy Agency participates in many of the MDEP activities. Started in 2007 with co-operation on various pilot project issues, the MDEP's expected outcomes are: (1) improved effectiveness and efficiency of regulatory safety design reviews, (2) increased quality of safety assessments, and (3) and identified areas for the convergence of regulatory requirements and practices. Making each regulator stronger in its ability to make sovereign safety decisions is a key objective that cuts across all MDEP activities. In 2008, the top regulators from each national authority met as the MDEP Policy Group and adopted the present structure and programme of work for the MDEP, including the pursuit of co-operation on specific safety design reviews and pursuing closer co-ordination on harmonisation and convergence issues such as digital instrumentation and control, mechanical codes and standards, and vendor inspections. The MDEP is currently a long-term programme that focuses in near term and interim results to share within MDEP and with other stakeholders. With effective communications in mind, the MDEP Policy Group directed the NEA to co-ordinate the Conference on New Reactor Design Activities with the purpose of communicating to a wide spectrum of stakeholders worldwide as to the program of work and accomplishments of the MDEP, and soliciting feedback and input from these stakeholders regarding recommendations on how to co-operate more efficiently on new reactor design reviews and to encourage standardisation and harmonisation on regulatory requirements and practices. Another key aspect of this Conference was to allow the various industry stakeholders to share their activities on new reactor designs and standardisation efforts. These stakeholders included non-MDEP regulators, vendors, licensees, reactor applicants, industry organisations, standards development organisations, etc. The Conference was held on 10-11 September 2009 at OECD Headquarters in Paris. These Conference Proceedings contain the details of the various sessions and the topics discussed as well as specific presentations given by panel members. (authors)