| Abstract: | A top-down reflooding model was developed for the French best-estimate thermal hydraulic code cathare. The paper presents the current state of development of this model. Based on a literature survey and on compatibility considerations with respect to the existing cathare bottom reflooding package, a falling film top-down reflooding model was developed and implemented into cathare version 1.3U. Following a brief review of previous work, the paper describes the most important features of the model. The model was validated with the Winfrith single-tube top-down reflooding experiment and with the REWET-II simultaneous bottom and top-down reflooding experiment in a rod bundle geometry. The results demonstrate the ability of the new package to describe the falling film rewetting phenomena and the main parametric trends both in a simple analytical experimental set-up and in a much more complex rod bundle reflooding experiment. |
