Heavy liquid metal cooled. Results 2002

Main issues of structural integrity, seismic integrity and operation are studied to confirm feasibilities of the medium size lead-bismuth cooled reactor as a candidate for one of the concepts of fast reactor in the feasibility studies on commercialized FBR cycle system. The results are following. (1) Integrity under loading of earthquake. (a) Reactor system: Seismic integrity of the reactor is confirmed. (b) Upper core structures and fuel exchanging machine: Those structures are necessary for increasing stiffness by bonding. (2) Structural integrity for thermal loading. Characteristics of both the medium size lead-bismuth cooled reactor and the large size sodium cooled reactor in the feasibility studies are arranged and structural integrity for thermal loading is evaluated about particular phenomena of thermal stratification and thermal striping. (3) Operation. Feasibility of the natural circulation operation is confirmed. (a) Water-steam supply system concerned with control system. (b) Control characteristics and transient characteristics of lead-bismuth reactor. (c) Initial start-up operation concerned with preheating and charging of coolant. (4) Safety. Core integrity on SG tube rupture is evaluated to be confirmed its safety, by analyzing thermal hydraulic behavior of transient of power, flow and temperature, by calculating characteristics of core and by evaluating additional reactivity by steam coming into core region. (5) Internal core structures design and system power balance design. (author)