Development of a Nuclear Reactor Two-Phase Natural Circulation CFD Model

摘要

A circuit of natural convection similar to the passive reactor heat removal systems of the AP600 reactor and of the APEX experiment was constructed in the Nuclear Engineering Institute located in Rio de Janeiro. In an attempt to improve usual numeric methods, it was developed a new Computational Fluid Dynamics (CFD) scheme to solve one-dimensional (1D) two-phase natural circulation transport equations. To compare the new scheme with other numeric methods, it was used the results of the two-phase experiment conducted at the University of Sao Paulo (USP). It was compared the frequency and the amplitude of the temperature oscillations at several positions of the spatial domain during a two-phase heating transient. The results of the new method show a better agreement with the experiment than that obtained from the RELAP and the TRAC series of computer programs.