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International audience; A benchmark analysis was launched within the Work Package on Core Safety of the EU FP7 cross-cutting project supporting the European Sustainable Industrial Initiative (ESNII), named ESNII+, aimed at providing a quantitative estimation of the uncertainties affecting the calculation of both core static neutronic parameters and safety coefficients of a Sodium-cooled Fast Reactor (SFR) low-void-effect core similar to the one considered for the Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID). Established deterministic and stochastic neutronic codes, as well as different nuclear data libraries, were employed by eight European organizations to perform a complete core characterization, with the ultimate goal to achieve consensus on computational methods and associated databases to be employed for advanced-design SFRs safety analyses. The comparison of the results obtained by the participating institutions provided quantitative information about capabilities and limitations of the different approaches, and about library effects, by highlighting the sensitivity of safety parameters to both computational techniques and nuclear data. Selected results of the first phase of the benchmark are presented and analyzed, along with a discussion of the planned RandD activities needed to improve the present benchmark status.

Modelling an attack tree is basically a matter of associating a logical "and" and a logical "or" but in most of real world applications related to fraud management the "and/or"logic is not adequate to effectively represent the relationship between a parent node and its children, most of all when information about attributes is associated to the nodes and the main problem to solve is how to promulgate attribute values up the tree through recursive aggregation operations occurring at the "and/or"nodes. OWA-based aggregations have been introduced to generalize "and" and "or" operators starting from the observation that in between the extremes "or all"(and) and "or any"(or), terms (quantifiers) like "several" "most" "few" "some" etc. can be introduced to represent the different weights associated to the nodes in the aggregation. The aggregation process taking place at an OWA node depends on the ordered position of the child nodes but it doesn't take care of the possible interactions between the nodes. In this paper, we propose to overcome this drawback introducing the Choquet integral whose distinguished feature is to be able to take into account the interaction between nodes. At first, the attack tree is valuated recursively through a bottom-up algorithm whose complexity is linear versus the number of nodes and exponential for every node. Then, the algorithm is extended assuming that the attribute values in the leaves are unimodal LR fuzzy numbers and the calculation of Choquet integral is carried out using the alpha-cuts.