In the year 2000 the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) was initiated. The main objectives of INPRO are: to help ensure that nuclear energy is available to contribute, in a sustainable manner, to the energy needs in the 21st century; and to bring together technology holders and users so that they can consider jointly the international and national actions required for achieving desired innovations in nuclear reactors and fuel cycles. INPRO has developed a set of basic principles, user requirements and criteria as a basis for the assessment of the Innovative Nuclear Energy System (INS) in the areas of economics, safety, environment, waste management, proliferation resistance, physical protection and infrastructure. The INPRO methodology, documented in the INPRO manual, provides guidance on how to apply these requirements in evaluating a given INS, taking into account local, regional and global boundary conditions that would apply to both, developing and developed IAEA Member States.