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An iodine immobilization matrix, the AgI–Ag2O–TeO2 glass system, was developed. The effects of different additives, i.e., Bi2O3, Al2O3, and PbO, on performance were investigated. In an ambient atmosphere and at 800 °C, the melting of the glass precursor mixture was completed after 1.0 h, without significant loss of the constituent elements of the glass except for aluminum. The loading of iodine in the matrix was approximately 11–15% by weigh, excluding oxygen. The normalized releases of all the elements from the matrix were below the order of 10−1 g/m2, which satisfies US regulation (2 g/m2). Additionally, each additive had a different effect on the glass system, and their effects on element release from the matrix were clarified. [ABSTRACT FROM AUTHOR]

In this study, iodine immobilization matrices were developed using PbO or TeO 2 as additives in AgI–Ag 2 O–V 2 O 5 glass systems. Excluding oxygen, iodine loading in the matrix was observed to be 32–36% by weight. The waste form was fabricated by melting at 800 °C for 1 h. The normalized release of elements in the waste form was below the order of 10−1 g/m2, thereby confirming the immobilization of iodine and satisfying the USA regulation (<2 g/m2). Iodine release was suppressed by the addition of PbO and TeO 2 ; however, silver release was not as suppressed as effectively as iodine. This paper also discusses the structural factors affecting the chemical durability of the glass matrix. [ABSTRACT FROM AUTHOR]

• Copper tellurite glass is developed for radioactive iodine immobilization. • The maximum iodine retention is approximately 13.79 wt% for the CuI waste form. • The CuI in the glass matrix causes an increase of Cu2+ and bridging oxygen. • All samples satisfy the US regulation of 2 g/m2 for the normalized release. Radioactive iodine-129 can easily diffuse into the environment and possesses a half-life of 1.57 × 107 years. Therefore, durable and stable waste forms are required for the treatment I-129. In this study, CuI·Cu 2 O·TeO 2 glasses were fabricated by incorporating CuI into a copper tellurite glass (0.3Cu 2 O·0.7TeO 2) matrix at different concentrations ranging from 0 to 30 mol%. The X-ray diffraction analysis confirmed the amorphous phase of all prepared samples, and X-ray fluorescence analysis verified iodine volatilization during the melting process. With the addition of 30 mol% CuI, the maximum iodine loading was approximately 13.79 wt%. X-ray photoelectron spectroscopy and Raman spectroscopy were used to understand the structure of the CuI·Cu 2 O·TeO 2 glass waste forms. As the CuI content increased in the glass matrix, there was an increase of +2-valent Cu and O BO. It was further confirmed that there were no significant changes in the structure of Te, which serves as the glass network former. Furthermore, all samples satisfied the US regulation of 2 g/m2 for the normalized release of all elements, as confirmed through the product consistency test. The proposed glass waste forms have cost advantages over previously developed silver-based glasses, making them a promising avenue for further research. [ABSTRACT FROM AUTHOR]

• Al, Bi, Pb, V, Mo, W were added to silver tellurite glass for I immobilization. • The thermal properties of matrix for radioactive I immobilization were evaluated. • The glass stability decreased by adding Bi 2 O 3 or PbO in silver tellurite glass. • The addition of MoO 3 or WO 3 raised T g and T c while keeping the glass stability. 129I is notable for its long half-life of 1.57 × 107 y and high mobility in the environment. It should be immobilized in a geological disposal environment through a stable waste form. In this study, additives including Al, Bi, Pb, V, Mo, and W were added to silver tellurite glass, and the thermal properties of this matrix for radioactive iodine immobilization were evaluated. The glasses were prepared by the melt-quenching method, including the melting of the glass precursor mixtures at 800 °C for 1 h. The loading of iodine in the matrix was approximately 11–15% by weight, excluding the oxygen element. Differential scanning calorimetry was performed to evaluate the thermal properties of the glass samples. The glass transition temperature (T g), crystallization temperature (T c), and glass stability were investigated. The addition of MoO 3 or WO 3 in the glass system increases T g and T c while maintaining the glass stability. [ABSTRACT FROM AUTHOR]

• Silver vanadate glass system was investigated to vitrify radioactive iodine waste. • The loading of iodine in the matrix was approximately 30–36% by weight. • The effects of Bi 2 O 3 and Al 2 O 3 on the matrix and iodine waste were investigated. • The addition of M 2 O 3 (M = Bi, Al) suppressed iodine release effectively. This study investigated the effects of Bi 2 O 3 and Al 2 O 3 on silver vanadate glasses for iodine immobilization. An iodine immobilization matrix was developed and examined with M 2 O 3 (M = Bi, Al) as additives for a AgI-Ag 2 O-V 2 O 5 glass system. Immobilization was confirmed at 800 °C after 1 h of melting without significant loss of the elements that constituted the glass, excluding aluminum. The loading of iodine in the matrix was approximately 30–36% by weight, excluding oxygen. Normalized releases of all elements obtained were below the order of 10−1 g/m2, which satisfies the USA regulation (2 g/m2). The structural factors that influenced the chemical durability of the glass and suppressed iodine release were discussed. The addition of M 2 O 3 (M = Bi, Al) suppressed iodine release by the formation of a VO 4 tetrahedron from the V 2 O 5 glass matrix. The release of silver was not as suppressed as that of iodine. [ABSTRACT FROM AUTHOR]

The long-lived radioactive forms of iodine pose significant environmental threats. Therefore, it is important to capture and immobilize radioactive iodine. In this study, an iodine immobilization matrix was developed and investigated by adding transition metal oxides such as WO 3 , MoO 3 , and V 2 O 5 to the AgI-Ag 2 O-TeO 2 glass system. The immobilization was confirmed by melting the glass precursor mixtures at 800°C for 1 h without a significant loss of the elements that comprising the glass. The loading of iodine in the matrix was approximately 13-15% by weight, excluding elemental oxygen. The normalized releases of all the elements obtained by PCT-A were below 10−1 g/m2, thereby satisfying the USA regulations (2 g/m2). The structural factors related to the chemical durability of the glass were discussed. The addition of WO 3 , MoO 3 , and V 2 O 5 suppressed the release of iodine by densifying the TeO 4 polyhedra. The silver release was not significantly affected by increasing the concentrations of the transition metal oxides. The additives stabilized tellurium, which is a glass network former, to prevent its release from the glass matrix. All the transition metals considered in this study remained stable in the silver tellurite glass in comparison to the release of tellurium. [ABSTRACT FROM AUTHOR]

The use of 235U as a fuel in nuclear power plants results in the formation of various fission products. Among them, 129I exhibits a long half-life (t 1/ 2 = 15.7 million years) and tends to easily volatilize, making its capture and treatment necessary. In this study, silver tungstate–tellurite glass (Ag 2 O·WO 3 ·TeO 2 with different mol% of AgI loading) was developed for radioactive iodine immobilization. The glass matrix was investigated by varying the fraction of Ag 2 O and/or WO 3. AgI was added to each matrix, ranging from 0 to 40 mol% in increments of 10 mol%. The glass samples were prepared by the melt-quenching process at 850 °C for 90 min. X-ray fluorescence analysis indicated no significant loss of elements in the samples, whose amorphous phase was confirmed by X-ray diffraction analysis. The effects of increasing the amount of AgI on the glass matrix are discussed considering the results of X-ray photoelectron spectroscopy. The leaching properties of all samples were evaluated via the product consistency test-A. Finally, the normalized release of all elements satisfied the US regulation of 2 g/m2. [ABSTRACT FROM AUTHOR]