Leaching behaviors and mechanisms of vitrified forms for the low-level radioactive solid wastes

• Published in: Journal of hazardous materials 2020-02, Vol.384, p.121296-121296, Article 121296
• Main Authors: Kim, Miae, Kim, Hyun Gyu, Kim, Shin, Yoon, Jang-Hee, Sung, Ji Yeong, Jin, Jong Sung, Lee, Mi-Hyun, Kim, Cheon-Woo, Heo, Jong, Hong, Kyong-Soo
• Format: Article
• Language: English
• Subjects: Corrosion behavior; Glass wasteform; Leaching test; Low-level radioactive waste
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121296

•Leaching experiments to two commercialized glass wasteforms were performed.•Leachabilities of nuclides satisfied the requirements of the Nuclear Regulations.•Glass compositions have made different results on the leaching behaviors.•Surface morphology of the glasses strongly affects its leaching mechanism. Leaching behaviors and mechanisms of commercialized glass wasteforms to sequester low-level solid-wastes were investigated: SG glass for resin waste and DG-2 glass for dry active waste. After ANS 16.1 leaching test, leachabilities of the nuclides, Co, Cs, and Sr, were all lager than 14, which met the requirement of the US-Nuclear Regulatory Commission. Holes of diameters 5–10 μm remained on the surface of the SG and crevices of lengths 10–50 μm were observed on the surface of the DG-2. We analyzed elemental compositions of the SG and the DG-2 with depths. For the SG, Si, Al, Ca, and Mg were accumulated and Na was depleted up to nearly 1.5 μm compared to an internal glass. For the DG-2, concentrations of B, Na, Al, Ca and Sr started to decrease from 2.5 μm even though other minor elements are still remained their concentrations. We suggested leaching mechanisms: alkali elements including H would diffuse through the holes on the SG, while most of the elements including Si and Al would diffuse through the crevices on the DG-2.