Quantifying aqueous plutonium using hybrid extractive scintillating resins

Hybrid extractive scintillating resins (HESR) were developed for uptake and detection of aqueous plutonium (Pu) in groundwater and surface water. These resins consist of titanium dioxide (TiO₂), which is responsible for Pu uptake, embedded within a scintillating polymer. The scintillating resin emits light when excited by alpha radiation from plutonium, which can be detected with a liquid scintillation counter without a scintillation cocktail. The physical characteristics of HESR were evaluated using thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Batch uptake measurements for aqueous plutonium-238 (+5 oxidation state) were performed using resin beads with diameters of 106-212 μm. For the HESR resin containing 57 wt% TiO₂, HESR (57), with a contact time of 1440 min, the Pu uptake was 88.9 ± 4.9 Bq/g with a conditional K_D of 860 mL/g. The corresponding plutonium detection efficiency was 96 %. HESR (57) displayed a linear Pu detection response, and a minimum detectable concentration of 0.38 Bq/L Pu(V) was calculated for a batch uptake experiment.