BOURRE™ glass fibres are commonly used as thermal insulation in nuclear power plants. In the event of a loss of coolant accident (LOCA) these fibres can be strongly corroded by the coolant. The pH value of the coolant is stabilised by H3BO3/NaOH buffering systems. Therefore, the chemical durability of BOURRE fibres was tested in this work. Isothermal single pass flow-through leaching tests were conducted. In addition, recirculating tests were performed with the temperature profile of the leaching medium similar to that in post-LOCA thermal conditions. Glass dissolution was followed by inductively coupled plasma optical emission spectroscopy and the corroded surface of the glass fibre was studied by scanning electron microscopy and energy dispersive spectroscopy.
