Abstract
The feasibility of low-enriched uranium (LEU) fuel as a replacement for the current, high enriched uranium (HEU) fuel for the High Flux Isotope Reactor (HFIR) has been under study since 2006. The current design for inner and outer element fuel plates includes a fuel region with spatially varying thickness along two dimensions. The fuel region is �beveled axially�, having reduced thickness regions of the U/Mo foils along the lower edges of the plates but not the upper edges. Reactor performance studies have been completed for conceptual plate designs and show that the reactor performance is unchanged or, for some parameters, slightly enhanced by converting to LEU fuel from HEU fuel and returning the reactor power to 100 MW from 85 MW. Two limiting transients have been analyzed and the response of the reactor with LEU fuel has been shown to be bounded by the current, HEU fuel.
