Small nuclear power reactors

Since nuclear power became an established source for electricity generation in the 1950s, the trend has been towards the development of large generating units. As specific capital costs decreased, the competitiveness of plants was further enhanced in this way. Nowadays, the investments required, and also public acceptance, may also make smaller plants eligible. The option of a modular expansion, even in steps, of nuclear power plants allows these units to be adapted to requirements. In this case, competitiveness is achieved not by the size of a plant but by the increased number of units to be built. Simplified design characteristics, the use of passive and inherent systems, are major design features guaranteeing safety and economic viability. The concepts currently under development worldwide are based on various combinations of plant design, primary coolant, and fuel.