Application of Small Reactor 4S

APPLICATION OF SMALL REACTOR 4S. 4S (Super safe, small and simple) fast reactor has been developed from 1998 with a joint work between CRIEPI and Toshiba. The main basic design concepts of 4S are long life core (10-30 years), negative void reactivity during core lifetime, passive safety design, easy and simple operation, less maintenance work and so on. To obtain these objects, a metallic fuel was selected and the annular reflector surrounding the whole core was selected for the burning control instead of control rod and other innovative technologies were applied, such as RVACS for decay heat removal. The electrical output of 4S is 10-50 MWe and its output will be used to provide electricity or heat to household, industry, seawater desalination for small city or community, and to mining and so on. For example, 4S with 50 MWe can product a fresh water of 200,000 m 3 /day. If the water consumption is 0.2 m 3 /day/capita, 1 million people can use its fresh water. 4S is a small reactor, however, there is a big market for the various utilization as a single or multiple purpose. At the present time, Toshiba and CRIEPI continues the preparation work for the US-NRC Pre-Application review for the future commercialization in the world.