Immobilization of Cs and Sr within perovskite-type Ba0.7-ySry(La, Cs)0.3ZrO3 glass/ceramic composite waste forms. Issue 23 (1st December 2022)

• Record Type: Journal Article
• Authors: Liu, Haifeng; Wang, Hua; Zhao, Jian; Li, Jie; Zhang, Xingquan; Yang, Jiacheng; Zhu, Yongchang; Xie, Ruishi; Zheng, Kui; Huang, Heyan; Huo, Jichuan
• Is Part Of: Ceramics international. Volume 48:Issue 23(2022)Part A
• Page Start: 34298
• Page End: 34307
• Publication Date: 2022-12-01
• Subjects: Perovskite -- Immobilization -- Caesium -- Strontium -- Glass/ceramic composite waste forms; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.08.007
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The disposal of radioactive Cs and Sr in high-level radioactive waste is a problem that needs to be considered in the nuclear industry. Currently, it is difficult to immobilize Cs and Sr simultaneously into a durable host phase, especially at low temperatures to avoid volatilization of Cs. Thus, perovskite-type Ba0.7- y Sr y (La, Cs)0.3 ZrO3 (y ≤ 0.6) polycrystalline was synthesized by sol-gel technique at low temperatures and developed as a host to immobilize Cs and Sr. The polycrystalline powders were further fixed in glass matrix to form the glass/ceramic composite waste forms. The results show that Cs and Sr can be immobilized effectively in the lattice positions of Ba0.7- y Sr y (La, Cs)0.3 ZrO3 at a low temperature (900 °C), without volatilization of Cs during the immobilization process. The glass/ceramic composite waste forms with a crystalline-amorphous phase inlaid structure, prepared with glass content of 40 wt% and sintering temperature of 800 °C, have low porosity, good compactness, and high hardness. The leaching rates of Cs and Sr in the waste forms can reach the order of 10 −3 - 10 −4 g m −2 d −1 after 14 days. This result provides an ideal host of Ba0.7- y Sr y (La, Cs)0.3 ZrO3 for simultaneous immobilization of Cs and Sr at low temperatures, and combines the advantages of traditional glass solidification and promising ceramic solidification. Graphical abstract: Image 1