Consideration of decontamination model for severe accident consequence assessment

Cost per severe accident, which can cover various kinds of consequences, namely health effects, economic, social and environmental impacts, has been used as an index for severe accident consequence assessment in the authors' previous studies. Decontamination of the contaminated area was concluded influential to the cost per severe accident, though it employed simple and conservative assumptions, which made further discussion difficult. A new decontamination model is formed to address this issue. A sensitivity analysis using the elementary effects method is performed to identify parameters which have large influence on the cost per severe accident. We identify 25 important parameters, and fix most negligible parameters to their medians to form a simplified decontamination model. Calculations of the cost per severe accident with the simplified model and the full model are performed and compared. The differences of the results of the two model are not significant, which ensure the validity of the simplified model. The cost per severe accident calculated by the simplified model is compared with the previous study. The decontamination cost increases its importance significantly. It is therefore necessary to pay attention to decontamination-related issues, e.g., determination of decontamination target area and decontamination waste management scheme.