Glass fibre is commonly used as therm,al insulation for the equipment in nuclear power plants. In case of LOCA (Loss Of Coolant Accident), the insulation could be damaged by the jet impact and carried to the screen of the emergency systems needed to cool the reactor. In this case, the fibres can be strongly corroded by particular cooler solutions and their behaviour under this environment can modify the head loss of screens. The pH value of coolant solution can be stabilised respectively by borate or phosphate buffering systems depending of the plants. A new type of small scale laboratory equipment allowing simultaneous study of the chemical durability of glass fibres and hydrodynamic conditions on the glass fibre bed placed on the screen was developed and tested.
