Development of a transient model for hydrogen generation in fuel-coolant interactions

A transient model for hydrogen generation by Fuel-Coolant Interaction(FCI) is developed with separate models for each FCI stage, coarse mixing and stratification. The model includes the physical concept of each FCI stage, heat and mass transfer correlation and the concentration diffusion equation with non-zero boundary condition. Using this model, we have simulated the Argonne National Laboratory(ANL-6548) tests that are single droplet experiments, and Fully Instrumented Test Site(FITS) tests that contain dynamic fragmentation and stratification. The model developed in this study predicted the amount of hydrogen generation more accurately than that of previous works. It is shown from the results of ANL tests that the larger metal particle is, the larger reaction rate is. And the metal particle size is a important factor to hydrogen generation. The calculated results of FITS tests are shown that the reaction rate of coarse mixing stage is higher than the stratification