Thermal-hydraulic numerical simulation of fuel sub-assembly using a dedicated meshing tool

This approach reveals to be of great help for modeling the sodium flow. Indeed, the pressure drop in the rod bundle is firstly evaluated. In addition, the local effects (at the scale of fuel pin) and global effects (at the scale of fuel pin bundle) for sodium velocity and temperature gradients for the alleged homogenization made by the spacer wire on the sodium flow are examined and clarified. Taking into account these results, the optimization of the fuel bundle geometry can be considered in order to homogenize the outlet temperature distribution in nominal condition. Lastly, the definition and the analysis of experiments on sub-assembly to be carried out in future experimental CEA platform, will also take advantage of this approach.