A decision supported system based on the combination of fuzzy expert estimates to assess the financial risks in high-level radioactive waste projects

This paper describes the technical aspects of the implementation of a Decision Aid System developed at ONDRAF/NIRAS/NERAS, the Belgian radioactive waste management agency. The proposed system is intended to deal with the economic and financial uncertainties inherent to Radioactive Waste Management (RWM) and especially to High-Level-Waste (HLW) repository projects. The economic calculus of such projects are particularly difficult due to many uncertainties that still exist regarding the final design, the eventual costs and the realization schedule. The general approach mainly relies on fuzzy logic rule-based systems to infer contingency or margin factors in such uncertain contexts. The parameters of the fuzzy models are identified based on preliminary rough estimates of the financial risks. This calibration enables to build a default system that can be further refined by the introduction of experts advices. The implemented software allows to introduce new information when available with the possibility to adjust the experts credibility.