Study on sodium-water reaction phenomena in steam generator of sodium-cooled fast reactor, 15; Numerical investigation of the wastage distribution close to crack

Onishi, Yuki*; Takata, Takashi*; Yamaguchi, Akira*; Ohshima, Hiroyuki; Kurihara, Akikazu ; Kikuchi, Shin  ; Uchibori, Akihiro 

A numerical method for self-wastage on a heat transfer tube has been developed to enable evaluation of the tube failure accident in a steam generator of sodium-cooled fast reactors. In this study, numerical analysis on discharging of water vapor from a crack was performed by using the SERAPHIM code calculating multicomponent multiphase flows with sodium-water chemical reaction. The numerical result showed that the high-temperature region appeared near the exit of the crack and the NaOH exists in the high-temperature region. We constructed a new Arrhenius-type evaluation model of a wastage rate and applied it to the numerical result. It was demonstrated that our model could reproduce expansion of the crack. The analysis mesh was reconstructed for the analysis region after expansion of the crack and the numerical analysis was performed again. The distribution of the gas-phase varied from the case of the initial crack.