Characterisation of residual stress and investigation of environmental effects on atmospheric-induced stress corrosion cracking of austenitic stainless steel nuclear waste containers

This research has investigated the conditions necessary for atmospheric-induced stress corrosion cracking to occur in material taken from an intermediate level nuclear waste storage container by means of experiments in a humidity chamber. It has also characterised the residual stresses associated with the container welds by modelling and measurement. Based on the work conducted in this research, the major findings can be summarised as follows:• Deliquescence of salt particles is dependent on relative humidity but independent of the quantity of salt present.• The time to initiate cracking may be sensitive to temperature, getting longer as the temperature decreases, but the timeframe of work as not long enough to establish this conclusively.• AISCC can occur at a stress (residual or applied) of 400MPa (0.2% strain) or more if the other necessary conditions are present. While AISCC was not observed when no stress was present, the threshold of stress below which AISCC will definitely not occur has not been determined in this work.