Corium melt quenching tests at low pressure and subcooled water in FARO

Simulation of Ex-Vessel Steam Explosion

“…Only about 0.3-0.5 mm in case KH-2_02. This is significantly lower than was measured in the FARO experiments, where the typical droplet size was in the range of 3-5 mm (Magallon and Huhtiniemi, 2001). But it should be stressed that in FARO experiments the conditions were different.…”

“…In the global model the jet fragmentation rate is deduced from the comparison to a standard case (i.e. typical conditions in FARO experiments (Magallon and Huhtiniemi, 2001)) and the size of the created droplets is a user parameter. In the local model the jet fragmentation rate and the size of the created droplets are calculated based on local velocities applying the Kelvin Helmholtz instability model.…”

“…Since the local model is very sensitive and in the process of being improved, the reference calculations were performed using the global jet breakup model. The diameter of the created droplets was set to 4 mm, what is the typical size of the melt droplets in the FARO experiments (Magallon and Huhtiniemi, 2001). The explosion module focuses on the fine fragmentation of the melt droplets, generated during premixing, and the heat exchange between the produced fragments and the coolant .…”

“…The global model is, strictly speaking, applicable only for single large very hot jets in a water pool, so that the fragmentation is due to the friction of the vapour film, whose characteristics are governed mainly by buoyant forces. The model was validated on FARO steam explosion tests (Magallon and Huhtiniemi, 2001), so extrapolations to situations far from those of FARO are questionable. In the model, the volumetric jet fragmentation rate to droplets is deduced from the comparison to a standard case as 2.…”

Review on Core Degradation and Material Migration Research in Light-Water Reactors

“…In addition to the facilities already mentioned, there are many other core degradation and melting material migration integral facilities, such as CODEX, which aims at investigating the core degradation within the light-water reactors (Hózer et al, 2000;Hózer, 2002;Hozer et al, 2003); LOFT, which aims at investigating the PWR core behavior during LOCA-type sequences (Jensen et al, 1989;Cronenberg, 1992); SANDIA-XR, which aims to determine the conditions under which steady lower core blockages are formed and those where they cannot be formed; SCARABEE, which aims to solve fast reactor security analysis and the behavior of fuel pool caused by a sub-assembly melting at full power; QUENCH, which is to explicitly investigate the effect of re-flooding on bundle degradation (Sepold et al, 2007(Sepold et al, , 2009Stuckert et al, 2010Stuckert et al, , 2011Stuckert and Steinbrück, 2014); with the tool FARO, researchers are able to conduct large-scale experiments in order to gain better knowledge of things including structure integration, coolant or molten core with less uncertainties considering relocation and melt progression (Hohmann et al, 1987;Magallon and Huhtiniemi, 2001); and KROTOS, aiming at exploring the problem of steam explosion (Magallon et al, 1996;Huhtiniemi et al, 1997;Annunziato et al, 1999;Huhtiniemi and Magallon, 2001). …”