Improving the Value of Risk Assessments for Fusion

This paper reviews the effectiveness of risk assessments performed for fusion reactor designs. Risk assessment methods have been used to improve safety and reliability and to assess the adequacy of designs. Based on our experience in performing and applying risk analysis, we have developed seven criteria for evaluation of usefulness. These criteria address the purpose, failure data base, assumptions, complexity, completeness, results, and presentation. We reviewed 19 fusion studies and rated them against these criteria. The results of the review are presented together with some examples of benefits received from risk studies. Finally, we present recommendations for improving the effectiveness of risk studies.