Using expert elicitation to characterise long-term tectonic risks to radioactive waste repositories in Japan

Siting and designing technological facilities that need to be located in regions susceptible to major tectonic events require evaluation of the full range of knowledge and appraisal of plausible alternative models and interpretations, all within a probabilistic framework. This challenge has been clearly demonstrated by the extreme effects of the March 2011 Tohoku earthquake and is nowhere more problematic than in siting facilities with hazard potentials that last for thousands of years, such as geological repositories for radioactive waste. The use of formalised expert elicitation to help derive credible impact scenarios and their likelihoods of occurrence is being trialled for the first time in the Japanese geological disposal programme. This paper looks at the methodology for eliciting expert judgement under uncertainty, and explores the broader possibilities of this approach for tectonic hazard forecasting.