Modeling dose rate increase from the addition of Uranium-232 for use as a tracer in uranium fuels

The isotope ²³²U is being considered for additive to uranium fuel for use as a tracer. The ²³²U decay chain has high energy gammas that can be used for tracer purposes. However, the presence and intensity of such gammas may increase effective dose rates to workers around such materials This study examines the dose rate from different uranium materials that varying amounts of ²³²U has been added to. Several materials and their respective storage geometries are modeled for particle transport calculations. For each material and ²³²U concentration, gamma source terms were generated using SCALE 6.2 ORIGEN. These source terms were then used in MCNP for each material and geometry. Upon analysis, it was determined that the baseline dose from enriched uranium dominates until the ²³²U concentration reaches about 10-100 parts per trillion (ppt), after which the dose rate increases linearly.