Abstract
In order to achieve increase of power outputs of an ABWR, it is extremely important to evaluate coolant flow in a lower plenum. Numerical simulation is helpful to predict the coolant flow. However the simulation results considerably depends on models, thus verification experiment is needed. Hence, the objective of the present study is the construction of the benchmark of CFD code for clarification the flow structure of a lower plenum. We constructed a 1/10 model of a lower plenum to conduct flow experiment for validation of CFD analysis. In the experiment, it turned out that coolant flow distribution becomes to be uniform at core support beam, and there are complicated flows around side entry orifices. These flow structures are also described by CFD analysis. As good performance of analysis, we investigated flow distribution to the core particularly by using CFD results, and mechanisms of these flows were discussed.
