A method for displaying imprecision in early radiological emergency assessments

This paper presents an approach to estimating and displaying the imprecision associated with predictions from early emergency response calculations based on a limited number of off-site measurements and incomplete information about the nature of the release. The method enables key elements of imprecision to be included in the assessment in a simple and transparent manner, notably those arising from alternative weather evolutions, release durations, and factors influencing the amount of radioactivity deposited to ground. The presentation of assessment results incorporating lack of knowledge in a way that is easily understandable is important in the context of emergency decision making, and options for alternative styles of display are presented and discussed. A new system of early emergency response for radiological releases to atmosphere based on this approach is under development.