New Developments in Representativity Approach to study Advanced Assembly Concepts in the EOLE Critical Facility

A new representativity approach based on sensitivity analysis of integral parameters to nuclear data, in the field of Advanced Assemblies Concepts (AAC) design is developped. The adopted scheme proposes an original approach to the problem, going from the initial « microscopic » pin-cells integral parameters to the whole « macroscopic » assembly integral parameters.. The originality of the present work is to develop an enhanced representativity theory based on pin-by-pin power distribution sensitivity to the nuclear data by using a particular application of the Generalized Perturbations Theory. This new development is shown to bring the complementary informations necessary to optimize the initial design and to meet target accuracy on the integral parameters to be measured.