The interaction between heavy liquid metal (HLM) and water is a safety concern for the preliminary designs of lead fast reactor and of subcritical transmutation system prototypes. Current pool-type configurations have the steam generators inside the reactor vessel. This implies that the primary to secondary leak (e.g. steam generator tube rupture) shall be considered as a safety issue in the design, but also in the preliminary safety analysis, of this reactor types. This requires availability of qualified experiments carried out with initial and boundary conditions representative of the reactor prototype. The objective is to support the development and to demonstrate the reliability of computer codes in simulating the phenomena of interest. LIFUS5/Mod2 is a separate effect test facility, designed for investigating the interaction between heavy liquid metal (HLM) and water, installed at ENEA CR Brasimone. LIFUS5 test facility is refurbished based on the operating experience acquired during the previous experimental campaigns and the support of numerical tools (i.e. SIMMER-III, -IV and, with some extent, RELAP5). The new design involves a new facility configuration, test section, instrumentation and control systems. This paper presents the new LIFUS5/Mod2 facility, the planned experimental campaign and code calculations devoted to support the design modifications, the instrumentation and the final test matrix. The activities are performed in the framework of the EC funded THINS Project and thanks the support of the Italian Ministry for the Economic Development.