Separation and purification of Sr-90 nuclide from a waste mixture

• Published in: Journal of radioanalytical and nuclear chemistry 2022, Vol.331 (1), p.275-281
• Main Authors: Lee, Byeonggwan, Choi, Jung-Hoon, Lee, Ki Rak, Kang, Hyun Woo, Eom, Hyeon Jin, Shin, Kyuchul, Park, Hwan-Seo
• Format: Article
• Language: English
• Subjects: Aqueous solution reactions; Barium; Batteries; Beta particles; Beta rays; Chemical fingerprinting; Chemical precipitation; Chemistry; Chemistry and Materials Science; Chromates; Coprecipitation; Diagnostic Radiology; Distillation; Hadrons; Heavy Ions; Industrial applications; Inorganic Chemistry; Nuclear Chemistry; Nuclear energy; Nuclear industry; Nuclear Physics; Nuclides; pH control; Physical Chemistry; Purification; Purity; Raw materials; Separation; Side effects; Spent nuclear fuels; Spent reactor fuels; Strontium; Thermodynamic efficiency; Zirconium
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-021-08082-3

Sr-90 is utilized as a raw material in various fields such as nuclear batteries, medical applications, and industrial use as a beta particle source. Therefore, high-purity Sr-90 is required to increase the thermal efficiency of nuclear battery operation or to prevent side effects on the human body during its use in medical therapy. Sr-90 is present in spent nuclear fuel and can be separated via reactive distillation through a pyrochemical process developed at the Korea Atomic Energy Research Institute, where Ba is obtained simultaneously via co-precipitation owing to its chemical similarity. In addition, Sr-90 decays into Zr-90 during the storage period after separation. Therefore, Ba and Zr-90 should be separated to obtain high-purity Sr-90 nuclides. In the present study, a separation and purification process is developed for the recovery of Sr-90 from a waste mixture containing Sr-90, Ba, and Zr-90. To separate Ba and Zr-90, the chromate precipitation reaction is modified via pH control, which can enhance the precipitation efficiency of Ba and prevent the co-precipitation of Sr owing to the excess amount of precipitants. A systematic study is conducted to optimize Sr-90 separation and purification processes, where a high yield of 84.3% is obtained, and a high purity exceeding 99.9% is maintained.