Challenges to the Acceptance of Probabilistic Risk Analysis. V. M. Bier, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706
In this talk, I will discuss some of the challenges to the acceptance of probabilistic risk analysis (PRA) by the general public, scientists, and the regulatory community. In particular, I will discuss the analysis of human error and organizational factors, the treatment of uncertainties (including the role of conservatism in regulatory decision making), the role of subjective judgment in PRA (especially as it relates to the distinction between public and private decision making), and the issues that need to be addressed in risk-based regulation. Some of these challenges (such as the existence of large uncertainties) are inherent to estimating the risks of severe accidents in complex engineered systems. Hence, these difficulties cannot for the most part be overcome through further PRA research, and may be largely unavoidable in fields with the potential for low-probability, high-consequence accidents. Other challenges represent weaknesses in current PRA methods, and might be overcome or at least reduced through suitable research efforts and/or adaptation of methods that have been developed in other fields. Thus, this talk will conclude with some suggestions for future research directions in engineering risk analysis.