Improvement of safety parameters in the CANDU reactor using burnable absorber erbium

Abstract

This work is concerned with the improvement of power coefficient of reactivity (PCR) and minimization of the coolant void reactivity(CVR) of a CANDU6 reactor. For this study, more reactive fuel so-called recovered uranium (RU) is introduced in the advanced CANFLEX fuel bundle. Burnable absorber Er2O3 (erbia) is used to maximize the Doppler effect and minimize the CVR of CANDU6 reactor. The optimal loading of erbia is investigated through lattice-based analysis. A 3-D equilibrium core is determined by using the standard time-average methods with an in-house code system. The core analysis is based on a hybrid two-step method in which the lattice analysis is performed by the Serpent Monte Carlo code and the 3-D core analysis is performed by a diffusion theory code named COREDAX. Also safety parameters are evaluated for the equilibrium core condition. Safety parameters of the 3-D core are compared with those obtained with simple lattice-based analysis.