Passive Containment Cooling System (PCCS) removes residual heat from upper drywell of the containment to the liquid pool surrounding the PCCS heat exchanger. It also has an important role in mitigating the offsite dose by retention of a fission product release in the containment. The operation of the PCCS is based on density differences between the containment and water pool
To study the behavior of the PCCS configuration planned to be used in the ABWR II concept and to gain experimental data for the validation work of MELCOR severe accident code, a scaled down PCCS model was designed and constructed at Lappeenranta University of Technology in Finland in 2012–2013. The PCCS model is connected to the drywell and wetwell compartments of PPOOLEX, which is acting as a host facility. Steam needed in the experiments is produced with the nearby PACTEL facility. The PCCS model consists of five horizontal U-tube shaped heat exchange tubes installed inside a secondary side liquid pool. The pool is in atmospheric pressure and covered by a lid with an exit pipe out of the laboratory and with viewing windows for video cameras.