Development and validation of FEM-LCORE code for the thermal hydraulics of open cores

In this report we discuss the development of the FEM-LCORE code for the study of three-dimensional thermal hydraulics of Iiquid metal reactors. The code solves the standard Navier-Stokes equations with turbulence models in the reactor upper and lower plena and a special model in the core where all the sub-channel assembly details are summarized in parametric coefficients. Advances in turbulence modeling are reported. In particular, the kω model and a new four-parameter turbulence model are discussed. Moreover, the implementation of parallel computing features in the code with the use of PETSc libraries is illustrated. With this new version of the code we investigate some assembly blockage events that can occur in the core in incidental situations and compare different behaviors for closed and open core models.