Exploration of producing Uranium-232 for use as a tracer in uranium fuels.

This study examines the production of 232U via neutron irradiation. Uranium-232 is considered for use as a tracer in nuclear fuel. However, a source of 232U is needed. This study examines the production of 232U via neutron irradiation of targets constructed out of either 231Pa or 230Th in the High Flux Isotope Reactor. HFIR targets were modeled in MCNP to determine 232U yield in protactinium and thorium targets. Flux tallies were used inside the targets to determine the neutron flux inside each target. This flux was then used in SCALE 6.2 ORIGEN to determine the 232U yield, as well as the buildup of the byproduct 233U. Several 230Th enrichments were examined to determine how 232U yield is affected by 230Th enrichment, as well as the effects of the presence of 232Th. The buildup of 228Th and 229Th in thorium targets was also examined, as these isotopes may impact the feasibility of recycling of thorium target materials. • Uranium-232 is considered for use as a tracer in uranium fuels. • Reactor irradiation of protactinium-231 and thorium-230 are considered to be the most viable means of production. • Protactinium-231 is considered the preferred target material, requiring only one neutron capture. • The High Flux Isotope Reactor was considered for production, with the flux trap being the preferred irradiation facility. • Target modeling determines that uranium-232 yield from thorium-230 targets is significantly impacted by resonance absorption. [ABSTRACT FROM AUTHOR]