Low Void Reactivity Fuel Effects on CANDU6 Core Integral Parameters

The paper continues earlier studies started to find out the influence of Low Void Reactivity Fuel (LVRF) using on core integral parameters. Some configurations of SEU-43 fuel bundle design with Dysprosium as burnable absorbers (BA) in the central element (CE) and 0.96% enrichment were taken into account in order to find out their suitability to be used in core burnup calculations. The voiding effect simulated by uniform reducing of the coolant density revealed that the Coolant Void Reactivity (CVR) decreases by 23-34% when 2% Dysprosium trioxide (Dy₂O₃) is added in the CE. Despite of penalties in Average Discharge Burnup (ADB) evaluated through DIREN time-average calculations, the presence of BA also lead to a slightly better uranium utilization revealed by DIREN refuelling calculations. Others safety benefits accompanying the BA using are also revealed. (author).