Quantitative analysis of microstructure evolution, stress partitioning and thermodynamics in the dynamic transformation of Fe-14Ni alloy

Li, L.*; Miyamoto, Goro*; Zhang, Y.*; Li, M.*; Morooka, Satoshi; Oikawa, Katsunari*; Tomota, Yo*; Furuhara, Tadashi*

Journal of Materials Science & Technology, 184, p.221 - 234, 2024/06

https://doi.org/10.1016/j.jmst.2023.10.037

Numerical simulation of distribution of melt component in reactor

Sato, Takumi; Hirata, Naoya*; Oikawa, Katsunari*; Nagae, Yuji; Kurata, Masaki

no journal, , 

Macroscopic segregation of molten core and melt components occurs with slow cooling rate in the accident of Fukushima Daiichi Nuclear Power Plants. In this study, solidification and microscopic segregation are simulated with the Scheil model and thermal properties calculated by Thermo-calc in order to investigate an influence of cooling conditions on macroscopic segregation. A macroscopic segregation behaviour has been calculated for UO-ZrO-FeO system, which are major oxides of molten core materials. According to calculated results, UO and ZrO was concentrated in initial solidification area. On the other hand, FeO were strongly concentrated in later solidification area. In addition, macroscopic segregation tends to be suppressed in the conditions of fast solidification rate and slow velocity of solidification interface.

Development of solidification and segregation model for molten corium

Sato, Takumi; Oikawa, Katsunari*; Ueshima, Nobufumi*; Nagae, Yuji; Kurata, Masaki

no journal, , 

Macroscopic segregation of molten core components occurs with slow cooling rate in the accident of Fukushima Daiichi Nuclear Power Plants. In order to investigate these segregation behavior, the solidification model for numerical simulation has been developed. In this model, solidification and microscopic segregation of molten corium are simulated with the Scheil model and thermal properties calculated by Thermo-calc. In this study, the validation of macrosegregation analysis of this model were performed. As the preliminary analysis, the calculation results were compared with corium solidification experiments. It was proved that this model can estimate the tendencies of macrosegregation.