Chemical and Mechanical Sustainability of Silver Tellurite Glass Containing Radioactive Iodine-129 (2021)

Cheong Won Lee, Jaehyuk Kang, Yong Kon Kwon, Wooyong Um, and Jong Heo 

Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT), 19(3), 323-330

DOI : https://doi.org/10.7733/jnfcwt.2021.19.3.323

ABSTRACT

Silver tellurite glasses with melting temperature of approximately 700°C were developed to immobilize ¹²⁹I wastes. Longterm dissolution tests in 0.1 M acetic acid and disposability assessment were conducted to evaluate sustainability of the glasses. Leaching rate of Te, Bi and I from the glasses decreased for up to 16 d, then remained stable afterwards. On the contrary, tens to tens of thousands of times more of Ag was leached in comparison to the other elements; additionally, Ag leached continuously for all 128 d of the test owing to the exchange of Ag+ and H+ ions between the glasses and solution. The I leached much lower than those of other elements even though it leached ~10 times more in 0.1 M acetic acid than in deionized water. Some TeO4 units in the glass network were transformed to TeO3 by ion exchange and hydrolysis. These silver tellurite glasses met all waste acceptance criteria for disposal in Korea.