Publication Details

Technical Paper TP12

Quantitative Risk Assessment in Various Industrial Sectors – Current Position, SAFERELNET

Author: S Medonos, Petrellus Ltd. Proceedings of the ESMG Symposium, 2004, Nurnberg, Germany.


The Paper provides an overview of the application of Quantitative Risk Assessment (QRA) in various industries in Europe. The most widely used method for the quantification of risk is that of Event Trees, which is often supplemented by application of the Risk Matrix approach, Cause-Consequence diagrams, Fault Tree Analysis, Failure Modes, Effects and Criticality Analysis, Bayesian Networks and Petri Nets.

The Paper gives examples of applications of QRA in the offshore oil and gas industry, petrochemical industry onshore and railways.

QRA uses “rule sets” to predict the effects of accidental loads on process facilities onshore and offshore. Rule sets for the survivability and functionality of pressurised systems affected by accidental fire often do not realistically predict the behaviour of the systems. This contributes to the uncertainties in the QRA and may lead to over-conservatism or inadequate design. 

The QRA techniques are summarised and the state-of-the-art methodologies identified as a result of the SAFERELNET initiative. SAFERELNET will also draw upon results of research in the academia that may be applicable in practical QRA.

Figure 1

Example of plot of frequency of exceeding a given explosion overpressure (in case of above Figure of 150mbar) over the site. 150mbar is equivalent to 10% probability of fatality for a metal frame / metal sided building.

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