Investigation of Different Sampling and Sensitivity Analysis Methods Applied to a Complex Model for a Final Repository for Radioactive Waste

The performance of different types of sensitivity analysis methods in combination with different sampling methods on the basis of a Performance Assessment model for a repository for Low and Intermediate Level radioactive Waste (LILW) in rock salt has been investigated. This paper provides an insight into the results obtained with the following methods for sensitivity analysis: (i) a graphical method (CSM plot), (ii) a rank regression based method (SRRC) and (iii) a simple first-order SI calculations scheme (EASI). These methods were combined with random and LpTau sampling. The most robust results were obtained using LpTau sampling. The results obtained with CSM and SRRC analysis are fairly comparable. The EASI results, however, assign the dominating role to a parameter that seemed to be of secondary importance according to the results of the two other methods before. In addition, in the early phase below 10 4 years, the EASI results seem to be of low robustness.