PAssive Systems: Simulating the Thermal-hydraulics with ExperimentaL Studies

ended

PASTELS aims to significantly increase the knowledge within Europe of innovative passive systems, namely SACOs and CWCs, and the ability of several European system and CFD computational codes to be able to accurately model key phenomena such as natural circulation loops and condensation. This is very challenging due to their very specific properties, i.e. small driving forces working against high resistive forces which are specific to the concept of these technologies. Given the growing use of the SACO and CWC technologies in non-European NPPs, it is essential, especially with the foreseen future use of Small Medium Reactors (SMR) that the European nuclear community is able to adapt its current numerical tools to this promising technology. Extensive experimental testing (SET, CET and integral experiments) with representative operating conditions on semi-industrial full scale test facilities (PKL facility [DE] and PASI facility [FI]) will provide essential data to support the improvement of the numerical activities. Existing data from PERSEO and HERO-2 facilities will also be used. The numerical and experimental activities will be conducted in an integrated step-by-step approach. PASTELS will investigate improvements to models, novel methodologies for the coupling of system and CFD codes working at different scales. Additionally, important knowledge on the behaviour of the SACO and CWC will be captured through the observation of their behaviour during the test campaigns. Different and similar computational codes will be used by the partners in order to be able to benchmark and compare the different results obtained, understand the causes and propose strategies to improve them. All project results will feed into extensive methodology guidelines and a roadmap to achieving licensing and implementation of these innovative passive system technologies in future European NPPs.