含铀微粒分析技术研究进展

Reaserch Progress of Uranium-Bearing Particle Analysis Technology

含铀微粒分析是核保障领域环境取样分析中的一项重要技术。在涉铀核活动尤其是铀浓缩过程中,会向环境中释放含铀气溶胶,其干燥后形成的含铀微粒与自然界形成的含铀微粒在同位素组成、元素组成、杂质组成等方面均存在明显差异。因此,可以通过分析所采集样品中微米或亚微米级尺寸含铀微粒的特征信息,为相应核设施、核活动的监测提供判断依据。经过近30年发展,目前已形成了较为成熟的含铀微粒分析方法体系。本文简单介绍了包括样品采集、初步筛选、微粒回收、识别及定位和测量在内的微粒分析流程,对比了各个环节常用技术手段的优缺点。同时,分别讨论了含铀微粒同位素分析、形貌及元素化合物组成分析、年龄分析三个研究方向的研究进展。最后,根据研究现状,结合国际原子能机构(IAEA)核查发展和实施支持计划(Development and Implementation Support Programme for Nuclear Verification),展望了未来含铀微粒分析技术的研究发展方向。

Uranium-bearing particle analysis is an important technology in the field of nuclear safeguards.In uranium-related nuclear activities,especially in the processes of uranium enrichment,uranium-bearing aerosols are unavoidable released into the environment.There are significant differences between the uranium particles formed by uranium-bearing aerosols after drying and that from nature in terms of isotopic ratio,elemental composition,and impurity composition.Therefore,we can provide a judgment basis for the monitoring of nuclear facilities and activities by analyzing the characteristic information of micrometer or submicron sized uranium-bearing particle.After nearly 30 years of development,some relatively mature methods for the analysis of uranium-bearing particles have been developed.In this review,the process of particle analysis including sample collection,preliminary screen,particle recovery,identification and localization,and measurement is briefly introduced.The advantages and disadvantages of the commonly used technical in each process are compared.At the same time,according to the different purposes of analysis,uranium-bearing particle analysis is divided into three research directions:uranium isotope analysis,morphology and elemental composition analysis,and age-dating.Recent progress of each direction is discussed. Finally, based on the progress of the research, combined with the Development and Implementation Support Program for Nuclear Verification of the IAEA, the future research direction of uranium-bearing particle analysis technology is prospected.