Maier Annika Carolin, Kegler Philip, Klinkenberg Martina, Baena Angela, Finkeldei Sarah, Brandt Felix, Jonsson Mats
Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10044 Stockholm, Sweden.
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - Nuclear Waste Management and Reactor Safety (IEK-6), 52425 Jülich, Germany.
Dalton Trans. 2020 Jan 28;49(4):1241-1248. doi: 10.1039/c9dt04395k. Epub 2020 Jan 6.
To assess the long-term leaching behaviour of UO, the main constituent of spent nuclear fuel, the oxidative dissolution of UO pellets was studied at high HO exposures ranging from 0.33 mol m to 1.36 mol m. The experiments were performed in aqueous media containing 10 mM HCO where the pellets were exposed to HO three consecutive times. The results indicate that the dissolution yield (amount of dissolved uranium per consumed HO) at high HO exposures is significantly lower compared to previous studies of both pellets and powders and decreases for each HO addition for a given pellet. This implies a change in redox reactivity, which is attributed to irreversible alteration of the pellet surface. Surface characterization after the exposure to HO, by SEM, XRD and Raman spectroscopy shows, that the surface of all pellets is significantly oxidized.
为评估乏核燃料的主要成分二氧化铀（UO₂）的长期浸出行为，研究了UO₂颗粒在0.33摩尔/米³至1.36摩尔/米³的高过氧化氢（H₂O₂）暴露量下的氧化溶解情况。实验在含有10毫摩尔/升碳酸氢根（HCO₃⁻）的水性介质中进行，颗粒连续三次暴露于H₂O₂。结果表明，与之前对颗粒和粉末的研究相比，在高H₂O₂暴露量下的溶解产率（每消耗的H₂O₂溶解的铀量）显著降低，并且对于给定的颗粒，每次添加H₂O₂时溶解产率都会降低。这意味着氧化还原反应性发生了变化，这归因于颗粒表面的不可逆改变。通过扫描电子显微镜（SEM）、X射线衍射（XRD）和拉曼光谱对暴露于H₂O₂后的表面进行表征，结果表明所有颗粒的表面都被显著氧化。
