Study on plant concept for gas cooled fast reactor

Moribe, Takeshi; Kubo, Shigenobu ; Saigusa, Toshiie; Konomura, Mamoru

In (Feasibility Study on Commercialized Fast Reactor Cycle System), technological options including various coolant (sodium,heavy metal, gas, water,etc.), fuel type (MOX, metal, nitride) and output power are considered and classified, and commercialized FBR that have economical cost equal to LWR are pursued. In conceptual study on gas cooled FBR in FY2002, to identify the prospect of the technical materialization of the helium cooled FBR using coated particle fuel which is an attractive concept extracted in the year of FY2001, the preliminary conceptual design of the core and entire plant was performed. This report summarizes the results of the plant design study in FY2002. The result of study is as follows. (1)For the passive core shutdown equipment, the curie point magnet type self-actuated device was selected and the device concept was set up. (2)For the reactor block, the concept of the core supporting structure, insulators and liners was set up. For the material of the heat resistant structure, SiC was selected as a candidate. (3)For the seismic design of the plant, it was identified that a design concept with three-dimensional base isolation could be feasible taking the severe seismic condition into account. (4)For the core catcher, an estimation of possible event sequences under severe core damage condition was made. A core catcher concept which may suit the estimation was proposed. (5)The construction cost was roughly estimated based on the amount of materials and its dependency on the plant output power was evaluated. The value for a small sized plant exceeds the target construction cost about 20%.