Fuzzy multi-criteria analysis of cutting techniques in a nuclear reactor dismantling project

Three different cutting techniques employed for dismantling the thermal shield of the Belgian BR3 nuclear reactor are analyzed within the framework of classical multi-criteria utility theory. This utilitarian approach allows to incorporate into the decision analysis factors which are difficult to quantify in monetary terms, such as the environmental impact of the cutting technique. A well-known drawback of this approach is that it imposes a linear ordering on the alternatives. In real-world situations, it is common practice to deal with alternatives towards which the decision maker is indifferent or which are incomparable to the decision maker. In order to allow for indifference and incomparability in the decision process, the problem is redefined in terms of a newly developed fuzzy methodology. This methodology leads to a fuzzy quasi-order relation in the set of alternatives that can be analyzed at different α-cuts, producing classical quasi-order relations. A remarkable asset is that this technique is equally applicable for the analysis of the criteria involved in the decision process. In conclusion, this approach results in a better understanding of the role of both alternatives and criteria in this MCDM problem.