Immobilization of contaminated sodium: an optimization study

•Safe disposal of contaminated sodium•Hydrogen evolution is avoided by using metal oxide mitigation process•Pristine glass with Ca and Zn maintaining Na/Si ratio as 1.34•The glass characteristics of U3O8 loaded BSG containing Na/Si ratio of 1.34 is reported for the first time to the best of our know...

Full description

Saved in:
Bibliographic Details
Published in:Journal of nuclear materials 2021-06, Vol.549, p.152899, Article 152899
Main Authors: Manivannan, A., Ravisankar, P., Saravanan, G., Senapati, Abhiram, Madhavan, R. Raja, Joseph, Kitheri, Muralidaran, P., Anthonysamy, S., Jayaraman, V.
Format: Article
Language:English
Subjects:
Argon
Boron oxides
Borosilicate glass
Cold crystallization
Composition
Contaminated sodium
Contamination
Crystallization
Crystallization,volatilization
Dilatometry
Heat treatment
Heat treatments
Immobilization
Minimum weight
Optimization
Scanning electron microscopy
Silicon dioxide
Sodium
Thermal expansion
Uranium oxide
Vaporization
Vitrification
Volatilization
Weight loss
X-ray diffraction
Zinc oxide
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Safe disposal of contaminated sodium•Hydrogen evolution is avoided by using metal oxide mitigation process•Pristine glass with Ca and Zn maintaining Na/Si ratio as 1.34•The glass characteristics of U3O8 loaded BSG containing Na/Si ratio of 1.34 is reported for the first time to the best of our knowledge. Borosilicate glasses (BSG) are promising vitrification matrix for immobilization of contaminated sodium. Nine compositions of BSG were synthesized with O/Si ratio ranging from 3.7 to 4.8 by melt quench method. X-ray diffraction technique and scanning electron microscopy were used to ascertain the amorphous nature of glass and crystalline nature of heat treated glass. Linear thermal expansion of borosilicate glasses was determined by dilatometry. Based on maximum loading of Na2O, high density, minimum weight loss during synthesis, and volatilization studies, BSG with 45.1 SiO2 – 30.4 Na2O – 11.1 B2O3 -7.3 CaO - 6.2 ZnO (mol %) was chosen as the recommended composition and also demonstrated the immobilization of contamination of sodium with the addition of U3O8. Cold crystallization of pristine and contaminated sodium revealed the formation of Na4Ca4(Si6O18) phase during heat treatment at 1013 K in air atmosphere. Volatilization studies of above chosen composition under dynamic argon flow showed a maximum of 0.2 % weight loss, an advantage during the homogenization of the melt.
ISSN:0022-3115
1873-4820
DOI:10.1016/j.jnucmat.2021.152899