Overview of the FZD and of the Institute of Safety Research / Counter-current flow limitation experiments in a model of the hot leg of a PWR

First, an overview of the FZD and of the Institute of Safety Research was presented. This includes in particular the departments of the institute, the main tests facilities and some examples of current research topics.
The second part of the presentation was focused on counter-current flow limitation experiments performed in a model of the hot leg of a pressurised water reactor. The background of this issue in the nuclear safety was introduced. Furthermore, the hot leg model of the TOPFLOW test facility and its particular operation in the pressure chamber were presented. The main results of the counter-current flow limitation experiments were shown in details, including the experimental procedure, a typical experiment performed with steam and saturated water at 50 bar, the method used to determine the flooding characteristics, the length characteristics in the Wallis parameter for channels with rectangular cross-sections and a comparison between air and steam experiments.