Automatic refueling simulation of a DUPIC fuel transition core

This paper presents an automatic refueling simulation of a 713 MWe Canada deuterium uranium (CANDU-6) reactor transition to Direct Use of Spent Pressurized Water Reactor Fuel in CANDU Reactors (DUPIC) fuel system. The simulation searches for a set of refueling channels based on the zone controller unit water level, the reactivity insertion tilt in two axial zones and the discharge burnup. Compared to the natural uranium core, the transition core has two distinctive features such as an axial power peaking and an inconsistent reactivity insertion into two axial zones with a fueling direction, which are accommodated by adjusting the reference power of the central zone and complying with the reactivity insertion tilt in the axial direction. Starting from the natural uranium equilibrium core, it took 730 full power days to completely fill the core with the DUPIC fuel, and the characteristics of the transition core represented by the maximum channel and bundle powers were far below the license limits.