Natural Gas distribution networks: how failures’ databases can improve existing safety performances

The highest possible safety levels must be ensured in Natural Gas (NG) distribution. In fact, very severe consequences to surrounding people, buildings and environment can verify in the case of Loss of Containment (LoC) from the system. To reduce the probability of occurrence inspection, renovation and monitoring activities are required to local Distribution System Operators (DSOs) that, however, have limited resources to be allocated for the purpose. Consequently, because of the size of the existing networks, priorities have to be clearly identified based on risk. Although the importance of the topic, no databases are currently present regarding accidents, emergencies and near missing occurred in NG distribution networks resulting very difficult to apply a risk based approach and representing an important lack to be answered. The paper is therefore divided as follow. In the first part a review of the existing risk based models is reported highlighting potentials and criticalities for their application in NG distribution market. In the second part the proposed risk based approach is described showing the potentialities but also the lacks currently present that obstacle its implementation. To conclude, qualitative suggestions and considerations concerning the design and the management of a dedicated failure database for NG distribution networks are reported.