France, Japan, US Collaborate on Reactor Design

Japan, France, and the US are expanding cooperation on the Sodium Cooled Fast Reactor Prototype (SFR). The SCFR is among the projects in the Gen IV Reactor Forum.

The sodium-cooled fast reactor uses liquid sodium to transfer heat to a working fluid for power generation. The SFR is designed for management of high-level wastes and, in particular, management of plutonium and other actinides (the radioactive elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103).

Important safety features of the system include a long thermal response time, a large margin to coolant boiling, a primary system that operates near atmospheric pressure, and intermediate sodium system between the radioactive sodium in the primary system and the power conversion system. Water/steam and carbon-dioxide are being considered as the working fluids for the power conversion system in order to achieve high-level performances in thermal efficiency, safety and reliability.

...The SFR’s fast spectrum makes it possible to use available fissile and fertile materials (including depleted uranium) considerably more efficiently than thermal spectrum reactors with once-through fuel cycles.

The envisaged SFR capability to efficiently and nearly completely consume trans-uranium as fuel would reduce the actinide loadings in the high-level radioactive waste it produces, according to a summary of the technology by the GIF. Such reductions would bring benefits in the radioactive waste disposal requirements associated with the system and enhance its non-proliferation attributes. Reducing the capital cost and improving passive safety, especially under transient conditions, are the major challenges for the SFR system.___Green Car Congress

Gen-IV reactors will be safer and more reliable--and produce less dangerous waste products--than conventional nuclear fission generators currently used. The SFR appears to have important advantages over other Gen-IV designs.

The three nation collaboration aims to standardise reactor and power plant design, and to facilitate conversion of older facilities to newer SFR plants.