Multi-Cycle Core Design Optimization with Multiple Input and Output Constraints

This paper presents a novel multicycle optimization framework designed to address the complexities of high burnup fuel (HBu) fuel deployment in light-water reactors (LWRs). HBu offers substantial economic benefits by enabling either longer operational cycles or reduced fuel requirements, thus lowering operational costs. However, the deployment of HBu introduces significant design challenges, including increased core reactivity constraints, heightened power peaking, and thermal design margin requirements, particularly for scenarios involving elevated enrichments and multicycle fuel management. To tackle these challenges, this study uses OPTIX, an advanced optimization tool that integrates uses parallel simulated annealing and APEX for reactor physics calculations. This paper presents initial results for multi-cycle optimizations with OPTIX. Results are presented for a single-cycle optimization and a two-cycle optimization. The core layout and possible assemblies are specified via user input, along with input and output constraints that must be satisfied. Both problems were able to be solved by OPTIX to generate a minimized total fuel cost. All input and output constraints were also satisfied by the optimized solutions. Several areas of improvement are identified as a result of these initial optimization calculations that can be implemented in OPTIX moving forward.