System design study of a small sodium cooled reactor

Chikazawa, Yoshitaka  ; not registered; not registered; Shiotani, Hiroki; not registered 

Small sized fast breeder reactors have a potential to use a power source applicable to diversified social needs. In the Feasibility Study of JNC, we will make a concept of small sized fast breeder reactor with various requirements of economical competitiveness, reactor safety, very long lived core, etc. The design requirements for a small sodium cooled fast reactor in Fiscal Year 2001 (FY 2001) were defined as follows; (Small sodium cooled reactor) (1)Electric Power : 150MWe (2)Fue1 Type : Metal (3)Coolant Circulation System : Forced Circulation (Tank or Loop Type) (4)Core Life : 10 years Based on a previous study of a small sodium cooled reactor, cost reduction of the plant with an electrical power of 150MWe was pursued. Concepts of its fuel, core and plant were designed and their main specifications were determined. The Reactor vessel was minimized and the diameter of the reactor vessel became 4 m. The reactor system was enhanced a passive safety to avoid a core melt even at ATWS. The construction cost of the whole plant was evaluated 340,000 yen/kWe and the economical goal (350,000 yen/kWe) was achieved. The constitution of a decay heat removal system was chosen which was a system of two PRACS and one RVACS driven by natural circulation in order to satisfy a heat removal condition of Category IV in Japanese Standard. Design Concept of a multipurpose reactor was studied. The purpose of the reactor was to produce hydrogen. It was performed with a membrane steam reformer. A potential to achieve the economical goal (17 yen/Nm) is shown.