Study on a Numerical Simulation for Thermal-Hydraulic Phenomena of Multiphase, Multicomponent Flows; Transient vaporization/Condensation Phenomena in Multicomponent System,2

Morita, Koji*; Matsumoto, Tatsuya*; Fukuda, Kenji*; Tobita, Yoshiharu; Yamano, Hidemasa   ; Sato, Ikkenn 

It is one of important problems for more reliable reactor safety evaluation to improve numerical simulation techniques for involved therma-hydraulic phenomena of multiphase, multicomponent flows in core disruptive accidents. In the present cooperative research, physical model development and experimental investigation were conducted for transient condensation phenomena of a vapor bubble with noncondensable gases to improve applicability of a fast-reactor safety analysis code for the phase-transition phenomena in multicomponent systems. This fiscal year experiments using steam mixed with nitrogen gas were performed for the transient bubble condensation phenomena, and then experimental data were obtained for relatively large-scale bubble behavior. In addition, experimental analyses was performed by the fast-reactor safety analysis code and its validity was discussed.