Bowing effects on isotopic concentrations for simplified PWR assemblies and full cores

Fuel assembly bowing effects on isotopic concentrations during depletion are investigated for a range of full-scale fuel assembly bow models for Simplified Pressurized Water Reactor (PWR) assemblies and full cores. First, two-dimensional (2D) 3 × 3 assembly arrays with a central fuel assembly displaced are simulated using both CASMO-5 and SERPENT-2. Investigations are carried out on burn-up evolutions and horizontal re-distributions of nuclide concentrations resulting from assembly bowing effects. Longitudinal distributions of the fuel content changes are also illustrated by simulating a three-dimensional (3D) assembly bowed in C-shape with SERPENT-2. Progressive deformations, varied bowing magnitudes and orientations are considered as influential factors for studying the impact of bowing. Finally, by implementing a measured bowing map from an operating reactor, simulations for 2D PWR full cores are performed with CASMO-5 to reveal the bowing impacts in terms of assembly locations.