Keywords: ZED–2 critical experiments, modelling, validation, WIMS–AECL, RFSP models, flux distribution, reactor design, safety analysis, transport calculation, cross–section condensation, CANDU lattices, reactor physics codes, Canada, pressurized heavy water reactors, PHWR, nuclear reactors, nuclear energy, nuclear power, nuclear safety, nuclear accidents, diffusion theory
Improvement in modelling ZED–2 critical experiments using WIMS–AECL/RFSP
The ZED–2 experiments were used for the validation of the WIMS–AECL/RFSP code suite. Two RFSP models (using the cross–sections provided by the WIMS–AECL lattice code) were constructed; one model used for calculations of regions just up to the critical heights, while the other model simulated explicitly the unmoderated region (called Improved Model herein). Results of the comparison between these two models, in terms of the biases in keff and reaction rates distribution, are presented. The Improved Model is more accurate in calculating both keff and flux distribution. Further studies are suggested to assess the validity of the diffusion theory at the interface between the moderated and unmoderated regions in the core.