Design and Execution of the Test Campaign on the Bayonet Tube HERO-2 Component

Innovative nuclear systems, such as the SMR and Gen-IV reactors, in order to achieve the goal of safety and economics, require relatively new approaches to accomplish at the fundamental function of heat removal, both in operative and accidental conditions. The heat exchanger compactness and operability in natural circulation are of great importance for such systems. ENEA in collaboration with POLIMI and SIET is leading some studies on innovative heat exchangers within the framework of a National Research Program funded by the Italian Minister of Economic Development. At the SIET laboratories in Piacenza, an important experimental campaign has been carried out to support the characterization of heat exchangers with bayonet tubes. The first thermalhydraulic tests conducted have allowed the creation of a valuable database for the characterization of the heat exchange, and for the detection and quantification of thermalhydraulic instabilities of the tubes under specific operating conditions, useful for the qualification of computer codes supporting the design and safety analysis of innovative nuclear reactors. It will also allow the performance comparison against alternative solutions, e.g. helical tubes steam generators, in different conditions of interest for SMR reactors.