Uncertainty characterization in risk analysis for decision-making practice

This document provides an overview of sources of uncertainty in probabilistic risk analysis. For each phase of the risk analysis process (system modeling, hazard identification, estimation of the probability and consequences of accident sequences, risk evaluation), the authors describe and classify the types of uncertainty that can arise.

The document provides:

• a description of the risk assessment process, as used in hazardous industries such as nuclear power and offshore oil and gas extraction;
• a classification of sources of uncertainty (both epistemic and aleatory) and a description of techniques for uncertainty representation;
• a description of the different steps involved in a Probabilistic Risk Assessement (PRA) or Quantitative RiskAssessment (QRA), and an analysis of the types of uncertainty that can affect each of these steps.
• annexes giving an overview of a number of tools used during probabilistic risk assessment, including the HAZID technique, fault trees and event tree analysis.