LAUSR

ABSTRACT Cation exchange chromatography has historically been used to concentrate plutonium (Pu) solutions during spent nuclear fuel reprocessing. Over time, availability of well-characterized and well-understood resins for this niche purpose has decreased. Additionally, new resin materials have come to market, necessitating a thorough evaluation of current cation exchange products for their effectiveness at concentrating Pu solutions. This study compares three commercially available 50W-X8 50–100 mesh cation exchange resins: Dowex™, AmberChrom™, and AG®. Herein, these resins are assessed for their loading capacity, uptake kinetics, and ability to concentrate dilute Pu solutions, initially using samarium (Sm) as a non-radiological surrogate. Results show no significant differences in loading capacities or uptake kinetics among the three resins for Sm. However, AmberChrom™ demonstrates slightly preferred properties, effectively concentrating a dilute Sm solution from 2.8 mM to 120 mM in a small column configuration (0.7 cm diameter). In a larger column setup (1.5 cm diameter), the AmberChrom™ 50W-X8 50–100 mesh resin concentrated a second Sm solution from 20.5 mM to 225 mM. Building on these results, the AmberChrom™ resin was then used to successfully concentrate a dilute Pu(III) solution from 20.5 mM to 221 mM with the larger column configuration. These findings highlight AmberChrom™ 50W-X8 50–100 mesh resin as a promising candidate for effective cation exchange chromatography applications in spent nuclear fuel reprocessing, particularly for concentrating dilute plutonium solutions, with the AG® resin being a close competitor.