Study on scaling analysis methods based on Lead-Bismuth loop with natural circulation

he natural circulation capability of the lead-bismuth eutectic (LBE) is outstanding and its use as the coolant is beneficial for improving the efficiency and passive safety of the advanced nuclear reactors. The scaled-down experimental facilities play an important role in further evaluating the natural circulation of lead-bismuth. Traditional studies of the scaling methods are carried out for water-cooled reactors. To provide the theory for the design of the scaled experimental facilities and further verify the traditional scaling methods for LBE flow, multiple methods such as H2TS and DSS were applied to an LBE loop in this study. A simplified single-phase natural circulation case was established using the Relap5 code and the corresponding criteria were deduced based on the different scaling methods. The study analyzed the steady and transient cases and the characteristics of several methods were compared. The results indicate that the H2TS and DSS methods can accurately simulate the steady cases of natural circulation in the LBE loops. For the transient conditions with power changes, the DSS method can simulate the initial stage of the dynamic process more accurately when the length ratio is small. As the length ratio increases, the transient deviation of all methods is reduced. In addition, when the power changes nonlinearly, the model obtained by the DSS method is more consistent with the prototype case than the H2TS method.