[en] The IAEA General Conference in 2000 invited all interested Member States to combine their efforts under the aegis of the IAEA in considering the issues of the nuclear fuel cycle, in particular by examining innovative and proliferation-resistant nuclear technology. Resolutions of the UN General Assembly in 2001 and 2002 provided additional endorsement for INPRO, by emphasizing the unique role that the IAEA can play in developing user requirements and in addressing safeguards, safety, and environmental questions for innovative reactors and their fuel cycles and stressing the need for international collaboration in the development of innovative nuclear technology. As of April 2003, INPRO had 15 members: Argentina, Brazil, Bulgaria, Canada, China, Germany, India, Republic of Korea, Pakistan, Russian Federation, Spain, Switzerland, the Netherlands, Turkey and the European Commission. The main objectives of INPRO are to: Help to ensure that nuclear energy is available to contribute in fulfilling energy needs in the 21st century in a sustainable manner; and to Bring together both technology holders and technology users to consider jointly the international and national actions required to achieve desired innovations in nuclear reactors and fuel cycles. The 21st century promises the most competitive, globalized markets in human history, the most rapid pace of technological change ever, and the greatest expansion of energy use, particularly in developing countries. For a technology to make a truly substantial contribution to energy supplies, innovation is essential. It will be the defining feature of a successful nuclear industry and a critical feature of international co-operation in support of that industry, co-operation that ranges from joint scientific and technological initiatives, to safety standards and guidelines, and to security and safeguards activities. Innovation is also essential to attract a growing, high-quality pool of talented scientists, engineers and technicians of the calibre and size needed to support a truly substantial nuclear contribution to global energy supplies. To set out the boundary conditions for the desired innovations of nuclear energy systems, INPRO established several task groups to define: Prospects and Potentials of nuclear power within the next 50 years; User Requirements for innovative nuclear energy systems (INS) in the area of Economics, Sustainability and Environment, Safety, Waste Management, Proliferation Resistance, and Cross Cutting Issues; and Methodology for Assessment of INS. Having completed these tasks, it is planned that several Member States will apply the INPRO methodology to make a judgement on the potential of INS under consideration for development, to specify corresponding research, development and demonstration (RD and D) needs for their development, and to identify improvements in the methodology. The results achieved as of the end of April 2003 (Phase 1A) are presented in this report. It is intended to issue separately the working material on which this report is based and which was produced at a number of consultancy meetings held during the course of the Project