Economic features of integral, modular, small-to-medium size reactors

The renewed interest towards nuclear energy is largely based on the escalation of fossil fuels prices and the global warming concerns. The nuclear option has to face not only the public opinion sensibility, mainly related to plant safety and waste disposal issues, but also the economic evaluation from investors and utilities, particularly careful on that energy source and in deregulated markets. Smaller size nuclear reactors (IAEA defines as “small” those reactors with power<300 MWe and “medium” with power<700 MWe) can represent a viable solution for both the stakeholders, especially for developing countries, or countries with not-highly-infrastructured and interconnected grids, or even for developed countries when limitation on capital at risk applies. A description of Small-Medium size Reactor (SMR) economic features is presented, in a comparison with the state-of-the-art Large size Reactors. A preliminary evaluation of the capital and O&M costs shows that the negative effects of the economies of scale can be balanced by the integral and modular design strategy of SMRs.