Simulation of reactivity control devices in a CANDU-6 reactor using DRAGON

A full core calculation for a CANDU reactor generally requires the knowledge of the few group cross sections associated with a fuel cell (2-D geometry) along with incremental cross sections representing the effect of inserting reactivity control devices in a supercell (3-D geometry). However, one generally observes that the supercell calculation with the reactivity device absent leads to a multiplication constant which may differ considerably from that obtained using the cell calculation. Here we propose to use DRAGON to perform both the cell and supercell calculation in a coherent fashion. First a cell calculation will be considered using DRAGON to generate multigroup fuel cross sections. This will be followed by an homogenization of the 2-D fuel properties to a 3-D supercell containing only the fuel using the SPH equivalence technique. One then expects that the few groups incremental cross section obtained using these multigroup fuel properties will represent more closely the effect of a given reactivity device in the reactor. (author). 6 refs., 4 tabs., 2 figs