Increasing transcurium production efficiency through directed resonance shielding

•Modeled the flux trap of the High Flux Isotope Reactor for transcurium production.•Identified sources of feedstock losses, primarily due to fission.•Identified energies where ratios of fission to (n,γ) absorption are highest.•Incorporated resonance absorbers at these energies to reduce fission losses in feedstock.•Shielding certain energy bands results in an increase in the efficiency of transcurium production.