Unstructured grid and unstructured grid porous methods for numerical analysis of TACR moderator calandria

In the design of the Thorium-based Advanced CANDU Reactor (TACR), the moderator system is used to remove the moderator heat in normal operations and to remove the residual heat in accidents. The numerical methods to analyze the heat transfer in the moderator calandria are required. In this paper, the moderator calandria is analyzed by using two types of numerical methods, an unstructured grid method and an unstructured grid porous method. Both methods use collocated unstructured grids and a new average filter method to eliminate the non-physical checkerboard pressure. The unstructured grid porous method introduces the porous method to consider the large tube bundles in the calandria. It is concluded that both methods are effective to analyze the thermal performance in the TACR calandria. Four different designs of the calandria are analyzed and are compared.