Applications and development of the PORFLO 3D code in nuclear power plant thermal hydraulics

PORFLO is a 3D two-phase flow simulation code which utilizes porous medium approach in the modeling of complex geometries. The code has been developed specifically for investigating various problems encountered in thermal hydraulic safety analysis of nuclear power plants. The code solution is based on the basic two-phase flow conservation equations with application-specific closure models for pressure loss, interfacial friction and heat transfer. The current main applications of the code include the simulations of flows in the horizontal steam generators of the Loviisa VVER-440 reactors and in the EPR reactor pressure vessel (RPV), and the modeling of the dryout behavior of porous core debris beds in the area of severe accident analysis. In the present work, the status of the code development, the main applications and the simulation results are summarized. In the case of the horizontal steam generator, the PORFLO simulation results are compared to the results obtained by the FLUENT CFD software. In the case of the core debris bed, comparisons to experimental data are also mad