Mitigation of source term in suppression pools: Large uncertainties in predictability

Highlights: • A jet scrubbing database has been gathered from the open literature. • The larger the in-pool aerosol retention, the larger the code deviations, regardless experimental conditions. • Modelling jet scrubbing should be properly addressed in the current severe accident codes. - Abstract: The Fukushima accident has revived the interest of suppression pools as a passive way to scrub radioactivity from the gas reaching the aqueous volume in case of a severe accident. However, modeling of pool scrubbing is far from being mature. This paper focuses on the scrubbing occurring at the nearby of the injection point and, by illustrating how far from observations prediction can be, it highlights the importance of developing proper models at this region of the pool. To do so, a specific simple ASTEC model has been set-up and a jet scrubbing database has been gathered from the open pool scrubbing literature by picking suitable tests in which all the key initial and boundary conditions were recorded and reported. In particular, low-submergence experiments with high injection velocity experiments have been chosen to address what is known as jet scrubbing (i.e., scrubbing at the inlet region when particles are carried in the pool by a gas submerged jet).