VALIDATION TEST PLAN OF A CANDU-6 MODERATOR TANK SCALED-DOWN TEST FACILITY

摘要

The computational fluid dynamics (CFD) codes play an important role in the accident analysis of CANDU-6 plants. However, a rigorous experimental validation of such codes is not an easy task but essentially required. To this end, the construction of a scaled-down moderator tank of a CANDU-6 reactor has been implemented. The parameters to consider for the validation are flow circulation and local temperature distribution inside the moderator during steady operation and major accident conditions. The key features to consider include the inlet jet development, buoyancy force, and viscous friction against the flow across the calandria tube array. In this paper, a 1/4 scaled-down test facility and instrumentation are described. Details of thermo-fluidic measurements using particle image velocimetry (PIV) are described and infrared (IR) thermography are addressed. Some progresses, including further issues and challenges, on the CFD modeling of the shear jet development at the periphery of the moderator circulation tank, the collision of the shear jets and their interaction with the upward buoyant flumes generated by local calandria tubes are presented. Furthermore, a method to validate the scaling of the CANDU-6 test facilities based on CFD analysis and similarity analysis is proposed.