Study of the distribution of steam plumes in the PANDA facility using CFD code

• The standard k–ɛ model has been verified for gas plume simulation in the large-scale volume.
• The k–kl–ω model has been improved for gas plume simulations.
• The sensitivity analyses about the computational mesh, time step, Froude numbers have been carried out.

During a postulated severe accident in light water reactor, a large amount of steam is injected into containment through the break. This would lead to the increases of pressure and temperature, and consequently threaten the integrity of the containment. In this study the light gas (saturated steam) distribution in a large-scale multi-compartment volume is simulated by using CFD code. Several turbulence models, including the standard k–ɛ model, the k–kl–ω model, the transitional SST model, and the improved k–kl–ω model with considering buoyancy effect are used for the simulation. The results show that both the standard k–ɛ model and the improved k–kl–ω model with considering the buoyancy effect can get good results comparing to the experimental results. The improved k–kl–ω model can get much better than the original k–kl–ω model without considering the buoyancy effect for predicting the steam distribution in vessels, and some characteristics in concerned region are predicted well. The sensitivity analyses about the computational mesh, time step, Froude numbers are also carried out.