FLICA-OVAP: A new platform for core thermal-hydraulic studies. FLICA-OVAP is a new platform dedicated to core thermal–hydraulic studies, funded by the Thermal–hydraulics Simulation project of CEA. It includes both subchannel scale and CFD scale capabilities. To provide a relevant response to different core concepts and multiple industrial applications, several models coexist in FLICA-OVAP platform: the homogeneous equilibrium model, the drift-flux model which is directly derived from the previous CEA core code FLICA-4 (Royer, Aniel, Bergeron, Fillion, Gallo, Gaudier, Grégoire, Martin, Richebois, Salvadore, Zimmer, Chataing, Clément, François, 2005. FLICA4: status of numerical and physical models and overview of applications. In: Proceedings of NURETH-11, Avignon, France), the two-fluid model, and finally, a general multifield model, with a variable number of fields for both vapor and liquid phases. For each model, an adapted set of closure laws is proposed concerning mass and heat transfer, interfacial and wall forces, and turbulence. The solving of equations is based on finite volume methods for multidimensional unstructured meshes. For instance, Riemann-type solvers, adapted to low Mach number, can be used for the numerical discretization of the convective part of the problem, while the diffusion part is discretized using a diamond-type solver, adequate for non-conforming meshes. An object-oriented architecture allows a flexible and efficient coexistence of several systems of equations, numerical solvers, and the manifold closure laws, which makes FLICA-OVAP a efficient tool for research purpose. The architecture also enables distributed parallel calculations, multidisciplinary couplings (with the neutronics codes CRONOS/APOLLO and with an integrated thermal solver for fuels rods and plates) or multiscale couplings (between different models in our platform or with the system code CATHARE). Some preliminary computations related to industrial needs will be presented in this paper.