Wijnia, Y.C., J. Flonk, and R. J. M. Hermkens: Reliability in the gas distribution infrastructure. Presented at Seminar Reliability, June 22 (2006). At: Delft, The Netherlands.
In the distribution of natural gas in the Netherlands, reliability is a special concept. It is not the availability of the service that is the key driver of investment and maintenance, but safety. In the event at the Julianaplein in 2003 it could be witnessed that a large emission of gas disrupted the traffic system for several hours, whereas the availability of gas for the neighbouring customers was not an issue. In the aftermath of this event (and others like Leiden 2001 and Amsterdam 2001), the Dutch Safety Board (Onderzoeksraad voor Veiligheid OVV) stated the self-regulation of the industry had failed. It suggested a substantial investment program to guarantee system integrity. This challenged the industry to prove that despite the incidents, the gas distribution system was very safe, and that such drastic measures would not be needed. However, the data to support such a claim was not available. First of all, no publicly accessible database existed that contained records of all relevant incidents. Secondly, there was no agreed upon method to combine all those incidents into a simple, easy to understand indicator of safety. In this paper we first explore the theoretical framework for such an indicator. Combining this framework with actual incident data will result in a quantitative model. Finally, we present the results of the quantitative model. The paper ends with an outlook for the application of the indicator in the quality regulation of the Dutch gas distribution companies.