Alteration of fuel debris simulants by Bacillus subtilis
Alteration of fuel debris simulants by Bacillus subtilis
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DOI：
10.1080/00223131.2022.2162995
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发表时间：
2023-01
影响因子：
1.2
通讯作者：
Jiangxue Liu;Yuma Dotsuta;T. Kitagaki;N. Aoyagi;Huiyang Mei;Masahide Takano;N. Kozai
中科院分区：
文献类型：
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作者：
Jiangxue Liu;Yuma Dotsuta;T. Kitagaki;N. Aoyagi;Huiyang Mei;Masahide Takano;N. Kozai
摘要本研究旨在揭示核燃料碎片中潜在的细菌变化。制备了由U0.5Zr0.5O2和Fe（0）组成的熔体模拟物和三种粉末模拟物（UO2、Fe（0）及其混合粉末），并在有氧条件下将其暴露于缺铁培养基中的枯草芽孢杆菌中。B。枯草芽孢杆菌不能从熔体模拟物中溶解Zr，但增强了U和Fe的溶解，尽管熔体模拟物的变化太小而无法评估。使用粉末模拟物的实验进行了详细调查细菌的影响。B。枯草芽孢杆菌促进了U从UO2粉末中的溶解和Fe从Fe（0）粉末中的溶解，尽管U的溶解很低。大部分的水相铀物种可能是U（VI），而作为固体相保留的U主要是U（IV）。该菌能氧化Fe（0）粉末，使其转化为水相和固体Fe物种。固体物质由无定形纳米尺寸的颗粒组成。溶解的Fe的一部分被吸附或沉淀到未溶解的UO2颗粒上。这些结果有力地表明，细菌可以降解核燃料碎片，虽然这项研究没有阐明氧化溶解的机制。
ABSTRACT This study aims to reveal the potential bacterial alteration of nuclear fuel debris. A melt simulant composed of U0.5Zr0.5O2 and Fe(0), and three powder simulants (UO2, Fe(0), and their mixed powder) were prepared and exposed to Bacillus subtilis in a Fe-deficient medium under aerobic conditions. B. subtilis could not dissolve Zr from the melt simulant but enhanced the dissolution of U and Fe, although the change of the melt simulant was too small to evaluate. Experiments using powder simulants were performed to investigate the bacterial influence in detail. B. subtilis enhanced the dissolution of U from the UO2 powder and Fe from the Fe(0) powder, although the dissolution of U was low. Most of the aqueous U species were probably U(VI), while the U that remained as a solid phase was mostly U(IV). The Fe(0) powder was oxidized by this bacterium, which transformed it into aqueous and solid Fe species. The solid species consisted of amorphous nano-sized particles. A fraction of the dissolved Fe was adsorbed or precipitated onto the undissolved UO2 particles. These results strongly suggest that bacteria can degrade nuclear fuel debris, although this study did not elucidate the mechanism of oxidative dissolution.