Improvement of Two-Fluid Model Based 1D Code with the State-of-the-Art Constitutive Equations for Two-Phase Flow in Rod Bundle.

In view of the importance of one-dimensional thermal-hydraulic analysis for rod bundle geometry, extensive efforts to improve constitutive equations have been made in recent years. In the present review article, state-of-the-art of the rod-bundle constitutive equations for flow regime map, void fraction, covariance, and interfacial area concentration models is reviewed. Among them, the constitutive relations for covariance and interfacial area concentration models may have the potential to improve the robustness of the conventional analysis method. Some sensitivity analysis results using TRAC-BF1 code with the new constitutive equations are summarized and reviewed. [ABSTRACT FROM AUTHOR]