Various organizations, including design organizations, utilities, universities, national laboratories, and research institutes, are involved in the develop­ment of advanced nuclear plants. The IAEA ARIS database (IAEA, 2010) summarizes global trends in advanced reactor designs and technology and provides balanced and objective information about all available designs.

Since this chapter focuses on the technology options that are available for newcomer countries, it will concentrate on the evolutionary reactor designs, as these are the most likely candidate technologies for most coun­tries’ first nuclear power plant, particularly in the near to middle term. For completeness, however, there will also be included a brief discussion exam­ining future trends for the development of nuclear reactors in the long term.

Evolutionary reactor designs have concentrated on improving the eco­nomics and the performance of existing nuclear reactors. At the same time, these designs meet even more demanding nuclear safety requirements than those currently in operation. While efforts have also been made in optimiz­ing the use of fissionable materials and minimizing the production of used fuel and nuclear waste, it is expected that the closure of the nuclear fuel cycle will only be achieved once innovative reactor designs come online.