Application of advanced self-shielding models to criticality-safety studies

Recent improvements made in resonance self-shielding algorithms for reactor physics calculations can certainly be applied to criticality-safety studies. In this paper we investigate the possibility of using resonance self-shielding models based on the subgroup approach, conjointly with innovative energy meshes such as SHEM extended to 295 and 361 energy groups, to generate sets of homogenized, self-shielded, macroscopic cross sections. These group constants are then used in a multigroup Monte Carlo calculation. To do so, the lattice code DRAGON has been combined with the Monte Carlo code MORET, using experimental benchmarks from ICSBEP as a framework for validation. Numerical results show great concordance with experimental values and those of others, well validated, criticality codes. (authors)