Plutonium Processing with Reillex ^TM HPQ Anion Exchange Resin – A Review

ReillexTM HPQ anion exchange resin is a critical tool in the processing and purification of plutonium. While many anion exchange resins have been used for this application, Reillex HPQ was designed specifically for this purpose and has remained the gold-standard since its development due to its resistance to harsh chemical and radiological conditions as well as superior plutonium sorption and elution kinetics. The literature is rich with experimental data regarding the use of Reillex HPQ resin for specific flowsheets and facilities including details on column operations, such as resin conditioning, plutonium loading, washing of impurities, and plutonium elution. Additionally, there are many important process steps and ancillary considerations including conversion of the as-received chloride form resin to nitrate form prior to processing, preparation of the resin for safe disposal, process analyses including in-line and asynchronous monitoring, and modeling and simulation. This review explores the relevant literature pertaining to plutonium separations by Reillex HPQ and is intended to be a resource thereof. Gaps in the literature have been identified, and recommendations for future research and development are made. Most importantly, further experimental work is recommended to characterize the performance of Reillex HPQ resin as a function of a broader range of important process variables including plutonium feed concentration, flow rate, and resin bed height. Additionally, improvements to the fidelity of Reillex HPQ process models are recommended. Finally, we note that much of the knowledge related to Reillex HPQ processing is institutional in nature and not always well documented. We endeavored to capture much of this from the Savannah River Site and Savannah River National Laboratory here, including providing a glossary of terms and recommendations to standardize future research.