CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Kui Liu,Kuibao Zhang,Ting Deng,Jianjun Zeng,Baozhu Luo,Haibin Zhang
Gd 2 Zr 2 O 7 ceramic is considered as one of the most promising host minerals for the immobilization of high-level radioactive wastes . Here, the effects of grain size on the aqueous durability of Gd 2 Zr 2 O 7 ceramics were studied. Two kinds of leaching experiments were used to research Gd 2 Zr 2 O 7 ceramic powders and bulks with different grain sizes (5 nm, 78 nm, 1 μm and 18 μm). The results demonstrate that the normalized leaching rates decrease with the increase of grain size. Through characterization and analysis, it is concluded that the hydrolysis reactions of Gd 2 Zr 2 O 7 occur in the leaching experiment and the hydrolysates are Gd(OH) 3 and Zr(OH) 4 . Besides, all the samples after leaching exhibit slight lattice contraction, which decreases with the increase of crystal grain size. The influence of leaching on the elemental distribution is most significant for the sample with grain size of 5 nm. This study has theoretical guiding significance for the application of Gd 2 Zr 2 O 7 immobilization.
研究领域:
材料科学
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核废料管理
·
环境化学
✓ 已验证
DOI
高影响因子
Science China-Chemistry
·
2025
·
IF 9.7
Li Jie,Zhao Yuting,Li Baoyu,Chen Lixi,Guo Qi,Song Wanrong,He Linwei,Chen Long,Zhang Mingxing,Chai Zhifang,Wang Shuao
Efficient segregation of TcO 4 − from high-level radioactive wastes (HLW) is critical for robust nuclear waste management and environmental protection. However, achieving deep decontamination is especially challenging in complex conditions of strong basicity, high radiation, and excessively competitive anions. Herein, we addressed the long-term challenge by modifying the imidazolium core with phenyl, trimethylphenyl, and benzyl groups in a flexible polymer chain, which constructs a precisely targeted microenvironment for selective TcO 4 − capture. This custom-engineered material (SCU-CPN-7) exhibits fast kinetics, high adsorption capacity (314.7 mg/g), excellent distribution coefficient (1.3 × 10 7 mL/g), and remarkable efficiency in TcO 4 − uptake under the combining extreme conditions of strong alkalinity (1 M NaOH) and high radioactivity. More importantly, owing to the synergistic effects of the hydrophobic effect, electrostatic affinity, and p- π interactions, SCU-CPN-7 demonstrates exceptional selectivity, capable of almost quantificationally removing TcO 4 − in the coexistence of a large excess of NO 3 − and SO 4 2− , leading to an unparalleled uptake performance of TcO 4 − from simulated HLW in both batch and dynamic column separation tests.
研究领域:
环境科学
·
核化学与放射化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·
IF 0
Cai Fangfei,Zhang Xiaoying,Ma Funing,Qi Linlin,Lu Di,Dai Zhenxue
The distribution coefficient ( K d ) of radionuclides is a crucial parameter in assessing the safety of high-level radioactive waste (HLW) geological repository. It is determined in the laboratory through batch and column experiments. However, differences in obtained K d values from distinct experiments have not been thoroughly assessed and compared. This study evaluated strontium (Sr) sorption on different granite materials using static batch and dynamic experiments (column and core-flooding experiments). The results from batch sorption experiments showed higher Sr sorption on granite under acidic and strongly alkaline conditions, low solid–liquid ratios, and low ionic strength. In column experiments, a two-site sorption model was used to simulate Sr transport in crushed granite and mixed pure minerals. The sorption of Sr on crushed granite exhibited a higher affinity than that of mixed pure minerals. The dual-porosity transport model was employed to investigate Sr transport behavior in fractured granite in the core-flooding experiment. K d obtained from batch sorption experiments are four to twenty times higher than those from column experiments, and two to three orders of magnitude higher than that from a core-flooding experiment. The results of this study provide valuable insights into safety assessment for the HLW geological repository.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
PubMed
RADIOCHIMICA ACTA
·
2021
·Vol. 110
·期 2
·107-119
·
IF 1.44
Yuzhen Sun,Hui Zhang,Rong Hua,Mingbiao Luo,Chuan-Pin Lee,Zhifen Wang,Weigang Liu,Jie Kong,Yunfeng Shi
Tamusu area is the primary pre-selection site of clayrock disposal repository for high-level radioactive waste (HLW) in China. However, the research on the migration behavior of nuclides in Tamusu clayrock is still in its infancy. For the first time in laboratory, the diffusion behavior of Re(VII) in Tamusu clayrock core was studied by means of through-diffusion method. The effects of pH, ionic strength and humic acid on the diffusion behavior of Re(VII) in clayrock were studied. The effective diffusion coefficient, apparent diffusion coefficient and rock capacity factor value were obtained. All the experimental conditions of Re(VII) diffusion in Tamusu clayrock are compared with other geological samples under the same conditions in literature data. The diffusion mechanism of radionuclide in Tamusu clay is discussed, which can provide experimental data for site selection and safety assessment of high-level radioactive waste repository in China. The experimental results showed an effective application and reference for the countries disposed HLW in mudrocks or clayrocks, such as France, Belgium etc. in Europe. Moreover, this research can provide the original data support for the metallogenic regularity and prospecting prognosis of rare element rhenium in different geological environments.
研究领域:
环境科学
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核废料管理
·
地质学
·
放射化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Cheng Meng,Wenqi Li,Chunrong Ren,Junchuan Zhao
Powellite ceramic represent one candidate to immobilize minor actinides and Mo from reprocessed UMo nuclear fuel. In this work, the Ca 1-x Li x/2 Ce x/2 MoO 4 (0 ≤ x ≤ 1) series is prepared via a solid-state reaction using Ce 3+ as trivalent minor actinide (Am 3+ ) surrogate, with structure/microstructure characterized by XRD , XPS, HRTEM , and SEM as well. The Ca 1-x Li x/2 Ce x/2 MoO 4 (0 ≤ x ≤ 1) compositions crystallize in tetragonal and are isostructural with scheelite. Rietveld refinements show that Ce 3+ and Li + simultaneously enter into the eight-fold coordinated Ca site of powellite crystal. The chemical durability of powellite phases is evaluated by the ASTM C1285-14 product consistency test method B. The leaching behaviours of Ce and Mo are accordance with the interfacial dissolution-reprecipitation mechanism. For all the Ca 1-x Li x/2 Ce x/2 MoO 4 (0 ≤ x ≤ 1) ceramics, 7-days NL Ce and NL Mo are found to be in the order of 10 −3 -10 −5 g·m −2 and 10 −2 -10 −4 g·m −2 respectively, which exhibit the great retention of Ce and Mo. Interestingly, the values of 7-days NL Ce and NL Mo are predominantly controlled by the distortion of MoO 4 tetrahedra and disordered arrangements of Ce 3+ and Li + . Thus, our initial understanding on the structure and chemical durability relation will provide insight to design new waste forms for the Mo-rich HLW condition.
研究领域:
材料科学
·
核废料管理
·
陶瓷工程
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）