The development status of nuclear power plants of small and medium capacities

Roughly half of the nuclear power plants at present in operation worldwide have capacities below 600 MWe. However, the percentage of small and medium sized nuclear power plants is on the decline, for most of them are prototypes or demonstration plants. The operating experience with these small and medium sized plants has been positive, the availabilities achieved as a rule having been in excess of those of the large standard size plants. In recent years, several manufacturers with practical experience in the market have elaborated proposals for small and medium capacity nuclear power plants on the basis of proven concepts and components. The design objectives purposed in those cases have been inherent safety economy, prefabrication or fabrication in the receiving country, standardization and modular design, easy shipping by barge or rail, high availability, simplicity and easy maintenance. It is expected that the present small reactors can be licensed with fewer conditions being imposed and that they meet the safety criteria for proven components recommended by IAEA. In view of the continuous further rises in oil prices, developing countries have expressed a pronounced interest in operating small and medium sized nuclear power plants. However, an important precondition of export orders is the existence of a reference plant. (orig.)