Visualization of Coupled Spectral and Burnup Calculations: an Intuition-building Tool

In this paper, we present a fast, user-friendly computational tool for the calculation and visualization of coupled neutron spectra and fuel burnup calculations. This tool, V:BUDS (visualize: burnup, depletion, spectrum), was designed to derive scenario-dependent material balances for fuel cycle systems studies. While V:BUDS does not replace more high-fidelity models, its simple interface, short computation time, and graphical output format make it a useful tool for classroom demonstration or student experimentation with a wide range of reactor phenomena. V:BUDS is a C-based code bundled with custom cross section libraries and driven by a graphical MATLAB TM front end. It operates at the unit cell level and couples a detailed multigroup treatment of energy dependence with a simplified collision probability model of spatial dependence. This approach gives strong fidelity to benchmarked standards for LWRs and responds correctly to perturbations in relevant parameters such as geometry and composition.