Safely probing the chemistry of Chernobyl nuclear fuel using micro-focus X-ray analysis
Safely probing the chemistry of Chernobyl nuclear fuel using micro-focus X-ray analysis
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使用微焦点 X 射线分析安全探测切尔诺贝利核燃料的化学成分
DOI：
10.1039/d0ta09131f
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发表时间：
2021
影响因子：
11.9
通讯作者：
Ding H
中科院分区：
文献类型：
--
作者：
Ding H
使用低放射性代用品的多模态微焦点X射线分析，推断出仍然存在于受损的切尔诺贝利反应堆4号机组中的固化熔融燃料的详细化学分析。熔化的UO2、核燃料包壳、混凝土、不锈钢和其他核反应堆部件的迷人混合物，这些材料表现得像熔岩，凝固形成复杂的高放射性玻璃陶瓷。使用元素特定的化学探针（微X射线荧光和X射线吸收光谱），结合微衍射分析，建立了这些异质材料的模拟物的晶相组合，其中包括“黑锰矿”和（U1− xZrO2）O2固溶体中的一系列成分。通过建立铀的氧化态和局部配位，不仅在这些结晶相中，而且在材料的无定形部分中也是独一无二的，这取决于核熔岩流过反应堆时的历史，从而获得了对核事故燃料化学的新见解。这项研究表明，微焦点X射线分析非常小的分数的材料可以产生丰富的化学信息，这可以应用于核熔化材料，以帮助退役和核燃料管理在核事故现场。
Detailed chemical analysis of the solidified molten fuel still residing in the stricken Chernobyl reactor unit 4 are inferred using multi-modal micro-focus X-ray analysis of a low-radioactivity proxy. A fascinating mixture of molten UO2, nuclear fuel cladding, concrete, stainless steel and other nuclear reactor components, these materials behaved like lava, solidifying to form a complex, highly radioactive glass-ceramic. Using element-specific chemical probes (micro-X-ray fluorescence and X-ray absorption spectroscopy), coupled with micro-diffraction analysis, the crystalline phase assemblage of simulants of these heterogeneous materials was established, which included “chernobylite” and a range of compositions in the (U1−xZrx)O2 solid solution. Novel insight to nuclear accident fuel chemistry was obtained by establishing the oxidation state and local coordination of uranium not only in these crystalline phases, but uniquely in the amorphous fraction of the material, which varied depending on the history of the nuclear lava as it flowed through the reactor. This study demonstrates that micro-focus X-ray analysis of very small fractions of material can yield rich chemical information, which can be applied to nuclear-melt down materials to aid decommissioning and nuclear fuel management at nuclear accident sites.