二流体モデルに基づく燃料デブリ熱挙動推定技術の開発

抄録

To reduce contaminated water at the Fukushima Daiichi Nuclear Power Plant and consider the fuel debris retrieval method, a numerical simulation method is required to evaluate the effects of water injection. Then, we are developing a multiphase CFD simulation method based on the three-dimensional two-fluid model to evaluate thermal-hydraulic behavior in the primary containment vessel of the Fukushima Daiichi Nuclear Power Plant. The numerical simulation method was developed by introducing the required functions into the ACE-3D, the three-dimensional two-fluid model analysis code developed by JAEA. This paper presents an overview of the porous model introduced to the ACE-3D to evaluate thermal-hydraulic behavior in fuel debris. In addition, we performed the numerical simulation for the Fukushima Daiichi Nuclear Power Plant unit 2 under the condition in which water injection stopped. And we compared the analysis results by the modified ACE-3D with more detailed three-dimensional CFD results by JUPITER.