【摘要】 核废料地质处置库UO2的氧化及氧化过程中放射性核素的迁移直接关系到处置库的安全性,为此,许多研究者在实验室研究了UO2氧化行为。然而,短期的实验结果无法直接外推地质处置库中长期氧化行为,天然类比研究为这种外推提供了可能,因此,UO2氧化的天然类比研究已经引起了广泛的关注。系统地总结了天然类比研究的现状,包括沥青铀矿与UO2的可比性、沥青铀矿风化产物的共生组合和共生次序、沥青铀矿及其风化产物的化学成分特征、沥青铀矿风化过程中类比元素的迁移性等;并初步指出了进一步研究的方向,如铀酰矿物的微结构研究、类比元素在沥青铀矿和铀酰矿物中分布的激光探针研究、地下水成分分析、模拟实验等。更多还原

【Abstract】 The behavior of UO₂ corrosion and the fate of radionuclids released during the corrosion of UO₂ are of critical signification for performance assessment of a spent fuel repository. In laboratory, therefore, corrosion of UO2 and mobility of radionuclids during the corrosion are detailedly researched by many researchers. However, the short-term experiment results may not be extrapolated to the long-term corrosion behaviors of the spent fuel in repository, and natural analogy provides a possibility for this extrapolation. Consequently, many studies on natural analogy were conducted. In this paper, the progresses acquired in the studies of natural analogy are summarized, including a comparison of structural properties, radiation damage and chemical composition between uraninite and UO₂, combination and paragenesis of alteration products of uraninite, chemical composition of uraninite and its secondary phases, mobility of analogy elements in the process of uraninite alteration. In addition, the problems in next studies are pointed out, e.g., characterization of micro-structure of secondary uranium minerals, high-resolution analyses of trance elements distributed in original and secondary uranium minerals using laser microprobe analyzer, composition of underground water, simulation experiments.更多还原