Design experimental facility for SMART Flow Mixing Header Assembly

SMART is an integral type nuclear cogeneration reactor developed in Korea. SMART (System-integrated Modular Advanced Reactor) adopts FMHA (Flow Mixing Header Assembly) to maintain the uniform distribution of the coolant temperature at the core inlet in the case of breakdown in the steam generator or pump. SMART FMHA is important to enhance thermal mixing of the coolant so that it is necessary to understand the thermal-hydraulic characteristics of FMHA. Therefore, the first goal of this study is to perform scaling analysis to design the experimental facility for SMART FMHA through CFD (Computational Fluid Dynamics) analysis on the SMART prototype and experimental model (Scale factor 0.18). After performing the geometrical scaling analysis for the SMART FMHA, the experimental facility could be configured considering the local form and friction losses with comparison of the results from two CFD analyses. Because FMHA has a complex geometry which is composed of lots of flow-holes and there is no available data such as the mixing efficiency and flow distribution of FMHA, the analysis can be performed by the use of CFD code. The experiments will be carried out using the FMHA experimental facility which is established from the scaling analysis. It is expected that not only the thermal-hydraulic characteristics of FMHA will be confirmed but also the optimum flow-hole size to enhance thermal mixing efficiency and the flow distribution capability of FMHA will be obtained through the experiments. (authors)