Conceptual design study of Pb-Bi cooled fast reactor core in the "feasibility study" in Japan
Sanda, Toshio; Yamashita, Takumi; Mizuno, Tomoyasu
A conceptual core design study is performed on Pb-Bi cooled fast reactor with forced circulation (FC) cooling in the Feasibility Study on Commercialized Fast Reactor Cycle System (FS) in Japan. From the viewpoint of Pb-Bi eutectic alloy application as reactor coolant, Pb-Bi/core material compatibility is one of the most significant issues. The previous core design study assumes that the maximum acceptable fuel pin cladding temperature is to be 650 deg-C and applies provisional cladding corrosion correlation based on a little available information of ferritic/martensitic steel-Pb(-Bi) compatibility studies. Recently new cladding corrosion correlation was proposed based on recent material corrosion tests in the Pb-Bi eutectic alloys, which suggests that the acceptable fuel pin cladding temperature is to be 570 deg-C. The core design is performed under the new corrosion conditions for 750MWe Pb-Bi cooled reactor. The designed core without upper axial and radial blanket achieves the target of the FS, such as 1.1 of breeding ratio and core average burnup of 150GWd/t, filling the demand from a plant design. And shielding structures around the core are set, shielding performance is checked.