The development of release scenarios for geologic nuclear waste repositories

Geologic nuclear waste repositories have been analyzed for almost a decade in order to determine the conditions or situations which could lead to the initiation of radionuclide release from the waste. This problem has been approached from both the generic and system-specific perspectives, and the assessments have applied expert opinion, fault/event tree, and simulation methods. The results from these studies suggest an emerging consensus that certain scenarios are potentially important and others are unimportant. Past approaches to scenario analysis may have been limited by lack of emphasis on internally-caused releases, the use of 'bounding' assessment strategies, and the concept of scenario analysis itself. Future work in the scenario analysis area should focus on strengthening the scientific basis of the analysis and the quantitative evaluation of the uncertainties in the predictions