STEAM. A novel experimental infrastructure for the development of the DEMO BOP water coolant technology

Within the roadmap of the technological development of the DEMO fusion power plant, a research activity has been undertaken at ENEA Brasimone Research Centre to design and realize a new multipurpose experimental infrastructure, conceived to investigate on the water and lithium-lead technologies applied to the DEMO breeding blanket and balance of plant systems. As part of the infrastructure, STEAM is a water facility designed to experimentally investigate the DEMO balance of plant, focusing the study on the steam generator of the breeding blanket primary heat transfer system. The STEAM facility is mainly composed by a water primary loop, working at the thermodynamic conditions of the breeding blanket primary heat transfer system (15.5 MPa, 328-295°C) and a secondary two-phase (liquid/steam) water loop reproducing the conditions of the DEMO power conversion system (6.4 MPa, 238-299°C). The two loops exchange thermal power by means of a test section (i.e. the steam generator) and the entire facility is designed to operate at a maximum power of 3 MW. The tests foreseen aim at investigating the DEMO balance of plant water coolant systems in steady-state and transient conditions, as well as at demonstrating the capability of the steam generator to perform as intended during the power phases of DEMO. The present paper aims at presenting the preliminary layout of the STEAM facility, describing the main components, the instrumentation and the operating conditions. Furthermore, a preliminary design of the once through steam generator mock-up envisaged for STEAM performed using the system thermal-hydraulic code RELAP5/Mod3.3 is presented.