Geological Disposal of Radioactive Waste and Spent Nuclear Fuel

Performance Assessment (PA) is a main component to show the feasibility and safety of High Level Radioactive Waste (HLW) repositories. PA uses complex models, usually called system models, which integrate several submodels and simulate the behaviour of the system along large time periods. PA involves, among other activities, Uncertainty Analysis (UA) and Sensitivity Analysis (SA). UA consists in identifying relevant uncertainties (model uncertainties, scenario uncertainties and parameter uncertainties) affecting the behaviour of the system and propagating them correctly into the output space, in order to characterise appropriately the uncertainty in the output variables used to determine if the system is either safe enough or not.