| After the Fukushima Daiichi nuclear power plant accident in 2011, significant attention was directed to investigate natural circulation thermal-hydraulics in Prismatic Modular Reactors (PMRs). Natural circulation is employed as a passive safety feature that passively removes the decay heat released after the loss of flow accidents (LOFA). Several computational studies have addressed such phenomena, however, validation of Computational Fluid Dynamics (CFD) is needed by providing high-quality data obtained from separate test facilities designed with reference to the corresponding reference PMRs. To address this need, a separate effects Plenum-to-Plenum Facility (P2PF) was designed and developed with dual channels and plena for experimental investigations of naturally driven gas thermal and velocity fields under different circulation intensities. Thermal and velocity measurements have been characterized by implementation of advanced sophisticated measurement techniques such as: (1) the hot wire anemometry (HWA), (2) flush-mounted micro-foil sensors, and (3) thermocouples that are capable of providing local measurements at different axial and radials positions along both channels. These measurement techniques have been integrated in a novel way so that the thermocouple readings are not disturbed by the HWA sensor, and vice versa. This proposed work has a significant impact on advancing the knowledge and understanding of the plenum-to-plenum (P2P) natural circulation thermal-hydraulic phenomenon and provides high-quality benchmark data that are much needed for verification and validation (V&V;) of computational fluid dynamics (CFD) models and codes. Therefore, computational simulations can be reliably used in designing PMRs passive safety systems and in safety analysis and assessment. |
