During an accident causing loss of the coolant of the primary circuit (LOCA) in a pressurized water reactor, partial or complete drying of the fuel assemblies may lead to the fuel temperature increase and significant deformation of the fuel rod claddings. In addition to the restriction of the flow area, the fragmented irradiated fuel relocation within the ballooned zone leads to an increase of the local residual power. The COAL experiments are part of the PERFROI project launched by "Institut de Radioprotection et de Sureté Nucléaire" with the support of the French National Agency of Research (ANR), EDF and the US-NRC. In this framework, IRSN has designed and developed those specific experiments focusing on the coolability issue of a partially deformed fuel assembly during the cooling phase by water injection with the safety systems using a 7x7 bundle of electrically heated rods. The effect of the flow blockage (intact geometry up to long ballooning with different blockage ratios 80 to 90%) will be evaluated for various mass flow rates and different pressures representative to Large (LBLOCA) and Medium break size (MBLOCA) configuration. This paper presents the thermal hydraulics parameters and the preliminary results of the experiments.