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Tsukimori, Kazuyuki; Iwata, Koji; Kawasaki, Nobuchika; Yada, Hiroki; Kasahara, Naoto
Transactions of the 20th International Conference on Structural Mechanics in Reactor Technology (SMiRT-20) (CD-ROM), 10 Pages, 2009/08
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.
Fujiwara, Kazushige*; Ito, Masanobu*; Sasanuma, Miwa*; Tanaka, Hideo*; Hirotani, Kiyoshi*; Onizawa, Kunio; Suzuki, Masahide; Amezawa, Hiroo*
Transactions of the 20th International Conference on Structural Mechanics in Reactor Technology (SMiRT-20) (CD-ROM), 8 Pages, 2009/08
Concerns over aged nuclear power stations are mounting in Japan today. However, there exists only a small number of experimental studies regarding the effect of radiation exposure to concrete. We have consequently conducted an irradiation test at JMTR on concrete specimens to confirm the effect of radiation exposure on the basic material properties of concrete. Irradiation temperature was kept lower than 65C. The maximum fast neutron fluence reached 1210 n/cm (E 0.1 MeV), which is sufficiently exceeding total fast neutron fluence to be exposed to the concrete located at the exterior of a reactor pressure vessel in a typical BWR for 60-year operation. Compressive strength of the irradiated concrete specimens was roughly equivalent to that of concrete specimens cured for the same duration under the standard environment. By measuring chemically bound water content of irradiated specimens, no changes after irradiation were observed. It was confirmed that radiation exposure did not significantly affect the basic material properties of concrete within the range of radiation doses adopted in this study.