Permanent disposal of Cs ions in the form of dense pollucite ceramics having low thermal expansion coefficient

• Published in: Nuclear engineering and technology Vol. 52; no. 1; pp. 115 - 122
• Main Authors: Omerašević, Mia, Lukić, Miodrag, Savić-Biserčić, Marjetka, Savić, Andrija, Matović, Ljiljana, Baščarević, Zvezdana, Bučevac, Dušan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2020; Elsevier; 한국원자력학회
• Subjects: Cs disposal; Hot pressing; Ion exchange; Thermal expansion; Zeolite; 원자력공학; Hot pressing; Thermal expansion; Zeolite; Ion exchange; Cs disposal
• ISSN: 1738-5733; 2234-358X
• DOI: 10.1016/j.net.2019.07.001

A promising method for removal of Cs ions from water and their incorporation into stable crystal structure ready for safe and permanent disposal was described. Cs-exchanged X zeolite was hot-pressed at temperature ranging from 800 to 950 °C to fabricate dense pollucite ceramics. It was found that the application of external pressure reduced the pollucite formation temperature. The effect of sintering temperature on density, phase composition and mechanical properties was investigated. The highest density of 92.5 %TD and the highest compressive strength of 79 MPa were measured in pollucite hot-pressed at 950 °C for 3 h. Heterogeneity of samples obtained at 950 °C was determined using scanning electron microscopy. The pollucite hot-pressed at 950 °C had low linear thermal expansion coefficient of ∼4.67 × 10−6 K−1 in the temperature range from 100 to 1000 °C.