Development of constitutive models for fast reactor design; Strategy of the study and results in the first half stage

Tsukimori, Kazuyuki; Iwata, Koji; Kawasaki, Nobuchika ; Yada, Hiroki ; Kasahara, Naoto

R&D to enable a practical fast breeder reactor plant is proceeding in Japan, which is called "FaCT (Fast reactor Cycle Technology development)". One of the key issues of R&D is to realize a reasonably small reactor vessel by eliminating the thermal liner which is installed inside the vessel in order to reduce thermal loading in the conventional design. Most important concern is the amount of the inelastic strain of the vessel accumulated around the liquid sodium surface which moves up and downward cyclically with start-up and shut-down. The aim of this study is to develop rational constitutive models that enable prediction of this kind of complex inelastic behaviors precisely and to prepare the design guide based on inelastic analysis. In this paper, the framework and strategy of the R&D and the results in the first half stage are introduced.