Before the nuclear accident in Japan, significant private-sector interest existed for the development of small modular nuclear reactors. It remains to be seen if that interest will continue.
Small and medium reactors are an interesting technology. At roughly 100-300 MW each, they are a very different sort of creature from the 1,000-1,400 MW units that are the standard for the commercial power industry today. Several companies are pursuing small modular reactors, that in fact are not so different in size from the reactors powering submarines and some nuclear powered ice-breakers.
It is on the commercial front, however, where many investors are particularly excited about small modular reactors (SMRs). This is because SMRs lend themselves to standardization in manufacturing, so that if contracts for reactors come in, leaning-by-doing should rapidly take place. The value in this standardized production and replication is that cost declines would be expected to rapidly take place. In many mass-produced technologies, the cost declines are dramatic: about a 20% decline for each doubling of production (Duke and Kammen, 1999). This means that if the cost per megawatt of, say, a 200 MW small reactor is comparable to large reactors then just to build a "standard" 1,000 MW nuclear power plant, five more units worth of experience and cost declines should result while the traditional reactor industry produced just one unit.