Effect of sucrose on the oxidation-reduction conditions and retention of rhenium during vitrification of low-activity waste

0567778 - ÚSMH 2024 RIV NL eng J - Článek v odborném periodiku
Khawand, J. - Kloužek, Jaroslav - Vernerová, Miroslava - Cincibusová, Petra - Hrma, P. - Kruger, A.A. - Pokorný, Richard
Effect of sucrose on the oxidation-reduction conditions and retention of rhenium during vitrification of low-activity waste.
Journal of Nuclear Materials. Roč. 573, JAN 2023 (2023), č. článku 154155. ISSN 0022-3115. E-ISSN 1873-4820
Institucionální podpora: RVO:67985891
Klíčová slova: vitrification * nuclear waste * rhenium retention * technetium retention * glass redox
Obor OECD: Ceramics
Impakt faktor: 3.1, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1016/j.jnucmat.2022.154155

Technetium speciation and solubility during nuclear waste vitrification are affected by oxygen partial pressure in the melt. Thus, reducing agents such as sucrose, which are routinely added to nuclear waste feeds to repress foaming, can significantly affect the volatilization of Tc and increase its retention in glass. Using Re as a surrogate for Tc, we measured the effect of sucrose addition to two low-activity waste melter feeds on the Re retention, oxygen partial pressure, and iron redox as functions of temperature. As expected, Re retention in glass increased as the sucrose content increased. This is attributed to sucrose reaction with nitrates and nitrites in the feed. Destruction of nitrates and nitrites reduces the salt phase fraction and thus likely promotes Re diffusion into the glass-forming melt. In agreement with available literature, we discuss that a modest increase in the sucrose content (compared to current practice) can significantly improve the Tc retention without reducing Fe 2 + to metal. (c) 2022 Elsevier B.V. All rights reserved.
Trvalý link: https://hdl.handle.net/11104/0342257