Stability of peroxide-containing uranyl minerals
Stability of peroxide-containing uranyl minerals
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DOI：
10.1126/science.1090259
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发表时间：
2003-11-14
期刊：
影响因子：
56.9
通讯作者：
Burns, PC
中科院分区：
文献类型：
--
作者：
Kubatko, KAH;Helean, KB;Burns, PC
含有过氧化物的矿物仅限于studtite，（UO 2）O-2（H2O）（4）和偏studtite，（UO 2）O-2（H2O）（2）。高温氧化物熔体溶液量热法和studtite的溶解度测量（298开尔文下的标准生成焓为-2344.7 +/- 4.0千焦/摩尔）确定这些相在含过氧化物的环境中是稳定的，即使在低H2 O2浓度下。铀存款中的天然放射性，或核废料的放射性，可以通过水的α辐解产生足够的H2 O2，以形成studtite。对于地质处置库中的核废物和长期储存的乏燃料，Studtite和metstudtite可能是重要的蚀变相，可能会以通常预期的氧化铀酰水合物和硅酸铀酰为代价。
Minerals containing peroxide are limited to studtite, (UO2)O-2(H2O)(4), and meta-studtite, (UO2)O-2(H2O)(2). High-temperature oxide-melt solution calorimetry and solubility measurements for studtite (standard enthalpy of formation at 298 kelvin is -2344.7 +/- 4.0 kilojoules per mole from the elements) establishes that these phases are stable in peroxide-bearing environments, even at low H2O2 concentrations. Natural radioactivity in a uranium deposit, or the radioactivity of nuclear waste, can create sufficient H2O2 by alpha radiolysis of water for studtite formation. Studtite and metastudtite may be important alteration phases of nuclear waste in a geological repository and of spent fuel under any long-term storage, possibly at the expense of the commonly expected uranyl oxide hydrates and uranyl silicates.