The Use of Default Values in Risk-Based Regulation. V. M. Bier, University of Wisconsin, Madison, Wisconsin
Regulators often lack the time to undertake their own risk assessments, and therefore must use analyses performed by licensees. Even validating a risk analysis can be extremely costly, often requiring nearly as much time and effort as performing the analysis. Therefore, regulators often choose to specify default values that are considered acceptable for use in risk analyses as input to regulatory decisions. While this can result in more uniform standards for risk assessments, it also departs from the intent of risk-based regulation; namely, to make regulatory decisions based as closely as possible on the actual risk level at each facility. This paper discusses the implications of varying degrees of conservatism in default parameter values and assumptions, and how the level of conservatism interacts with other aspects of the regulatory system. For example, we show that defaults at or near the population average can result in non-conservatism overall, with the greatest non-conservatism occurring at the sites with the highest risk. In this situation, regulators need to pay special attention to encouraging licensees to generate risk insights based on site-specific rather than default data, and to reveal those insights to the regulatory body. Conversely, if defaults are set very conservatively, regulators may have little incentive to approve deviations from the approved defaults, resulting in a highly inefficient regulatory system.
Supported by the Korea Atomic Energy Research Institute and Mr. Seung-Cheol Jang.
Go to . . .