Optimization and validation of the CFD modules in the NURISP platform (CIRTEN Report RdS/2012/1352-UNIBO, NNFISS-LP2-089)

The NURISP European project is based on a group of codes developed to simulate the thermal-hydraulic behavior of nuclear plants and components. Each code should be a module inside a large application based on the open-source SALOME platform. The platform should be able to load and unload different modules in order to combine the study of multiphysics and multiscale problems. Different modules may be used to investigate physical phenomena at different scales ranging from boiling bubbles detaching from a heated surface to nuclear reactor system evolution. In this work first we discuss the status of the different modules integration inside the SALOME GUI and MPI libraries. Then we focus on TRIO U, NEPTUNE and CATHARE modules and apply those modules for validation purposes on previous studies and experiments. CATHARE is a lumped parameter thermal-hydraulic code used to investigate the time dependent behavior of complex systems. A CATHARE model for the SPES-99 facility has been improved and validated against experimental data. TRIO U, a three dimensional two-phase code, is validated against some experimental data involving release time of bubbles detaching from heating walls. Finally NEPTUNE, a multidimensional solver for multiphase flow equations, is used to reproduce the experimental data collected in the steam suppression pool during Test n.9 on the PERSEO facility. Boundary conditions for the NEPTUNE simulation of the steam suppression pool are taken from a pre-existant CATHARE simulation of the entire system evolution. In the final part of the report we study the integration of modules inside the SALOME platform using the open-source SATURNE as template code.