摘要：
The development and application of new and efficient adsorption materials are key issues in the treatment of nuclear wastewater. This paper introduces a novel hierarchical porous amidoxime cellulose monolith synthesized through thermally induced phase separation (TIPS). The inherent hydrophilicity of cellulose, combined with the graded porous structure achieved through TIPS (with a specific surface area of 10.36 m2/g), endows the material with strong mass transfer ability. The adsorption properties of this amidoxime cellulose monolith for uranyl ions were evaluated in both batch and flow -through column adsorption scenarios. Remarkably, the adsorption saturation was achieved within a concise period of 13 h in batch adsorption. The hierarchical porous structure of the amidoxime cellulose monolith exhibited exceptional adsorption performance for uranyl ion, achieving a removal rate of 99.99 %. Moreover, this removal rate was sustained for 200 min, and the monolith proved recyclable for at least 5 cycles in flow -through column adsorption tests involving nuclear wastewater. When used for adsorption in real wastewater environments, the material achieved the removal of over 99.96 % of total alpha and beta radioactivity. These findings underscore the high efficiency of the newly developed hierarchical porous amidoxime cellulose monolith in uranyl ion adsorption. They emphasize its substantial potential for the efficient adsorption and removal of uranyl ion from nuclear wastewater.
作者：
Song Luo;Dong-Meng Zhang;Lin-Jing Qi;Xun Chen;Peng-Cheng Chu;...
期刊：
中国物理C,2024年48(4):044105 ISSN：1674-1137
作者机构：
[Song Luo; Dong-Meng Zhang; Lin-Jing Qi; Xun Chen] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;[Peng-Cheng Chu] School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266033, China;National Exemplary Base for International Sci & Tech. Collaboration of Energy and Nuclear Safety, University of South China, Hengyang 421001, China;Cooperative Innovation Center for Nuclear Fuel Cycle Technology & Equipment, University of South China, Hengyang 421001, China;Key Laboratory of Low Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410081, China
摘要：
In this study, α-particle preformation factors in heavy and superheavy nuclei from 220Th to 294Og are investigated. By combing experimental α decay energies and half-lives, the α-particle preformation factors are extracted from the ratios between theoretical α decay half-lives calculated using the Two-Potential Approach (TPA) and experimental data. We find that the α-particle preformation factors exhibit a noticeable odd-even staggering behavior, and unpaired nucleons inhibit α-particle preformation. Moreover, we find that both the α decay energy and mass number of parent nucleus exhibit considerable regularity with the extracted experimental α-particle preformation factors. After considering the major physical factors, we propose a local phenomenological formula with only five valid parameters for α-particle preformation factors . This analytic expression has a clear physical meaning as well as good precision. As an application, this analytic formula is extended to estimate the α-particle preformation factors and further predict the α decay half-lives for unknown even-even nuclei with Z = 118 and 120.
作者机构：
[Dong-Meng Zhang; Xiao-Yuan Hu; Lin-Jing Qi; Ming Li] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;[Hong-Ming Liu] Institute of Modern Physics, Fudan University, Shanghai 200433, China;National Exemplary Base for International Sci & Tech. Collaboration of Nuclear Energy and Nuclear Safety, University of South China, Hengyang 421001, China;Cooperative Innovation Center for Nuclear Fuel Cycle Technology & Equipment, University of South China, Hengyang 421001, China;Key Laboratory of Low Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410081, China
摘要：
In this study, proton emission half-lives were investigated for deformed proton emitters with based on the presented deformed Gamow-like model, where the deformation effect was included in the Coulomb potential. The experimental half-lives of proton emitters can be reproduced within a factor of 3.45. For comparison, the results from the universal decay law and the new Geiger-Nuttall law are also presented. Furthermore, the relevance of the half-lives to the angular momentum l for 117La, 121Pr, 135Tb, and 141Ho were analyzed, and the corresponding possible values of l were proposed: l = 3, 3, 4, 4.
作者机构：
[Yizhuohang Liu] School of Nuclear Science and Technology, University of South China, Hengyang,China, Hengyang, Hunan, 421001, CHINA;[Pingwei ZHENG] School of Nuclear Science and Technology, University of South China, University of South China, University of south China, 28 Changsheng west road, Zhengxiang district, Hengyang city, Hunan province, China, Hengyang, Hunan, 421001, CHINA;[Xueyu Gong] , University of South China, School of Nuclear Science and Technology, Hengyang, 421001, CHINA;[Lan Yin] School of Electrical Engineering, University of South China, Hengyang,China, Hengyang, Hunan, 421001, CHINA;[Xiaochang Chen] , Department of Physics and Materials, Nanchang University, Jiangxi, Nanchang 330031, China, Nanchang, 330031, CHINA
摘要：
According to the physics of tokamak start-up, this paper constructs a zero-dimensional (0D) model applicable to electron cyclotron (EC) wave assisted start-up in NCST spherical torus (spherical tokamak) and CN-H1 stellarators. Using the constructed zero-dimensional model, the results obtained in this paper under the same conditions are compared and validated against references results for pure hydrogen plasma start-up in tokamak. The results are in good agreement, especially regarding electron temperature, ion temperature and plasma current. In the presence of finite Ohmic electric field in the spherical tokamak, a study on the EC wave assisted start-up of the NCST plasma at frequency of 28 GHz is conducted. The impact of the vertical magnetic field Bv on EC wave assisted start-up, the relationship between EC wave injection power Pinj, Ohmic electric field E, and initial hydrogen atom density nH0 is explored separately. It is found that under conditions of Ohmic electric field lower than ITER (~ 0.3 V m-1), EC wave can expand the operational space to achieve better plasma parameters. Simulating the process of 28 GHz EC wave start-up in the CN-H1 stellarator plasma, the plasma current in the zero-dimensional model is replaced with the current in the poloidal coil of the stellarator. Plasma start-up can be successfully achieved at injection powers in the hundreds of kilowatts range, resulting in electron densities on the order of 1017 to 1018 m-3.
期刊：
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS,2024年:1-19 ISSN：1951-6355
通讯作者：
Dimiter L. Balabanski<&wdkj&>Wen Luo
作者机构：
[Dimiter L. Balabanski] Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), Bucharest-Magurele, Romania;[Wen Luo] School of Nuclear Science and Technology, University of South China, Hengyang, China
通讯机构：
[Dimiter L. Balabanski] E;[Wen Luo] S;Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), Bucharest-Magurele, Romania<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang, China
摘要：
Nuclear photonics is a emerging field of science which combines research with new generation
$$\gamma $$
-ray sources based on traditional and laser-based electron accelerators. Here, we discuss isomeric studies carried out with
$$\gamma $$
-ray beams having either continuous, or quasi-monochromatic photon spectra. In experiments with high-power lasers, intense secondary radiation sources are generated. Such experiments explore isomer population or de-excitation in plasma environments. Laser-accelerated particle beams with high charge also facilitate high-energy nuclear excitations, leading to efficient production of nuclear isomers with higher lying isomeric state (reaching MeV energy level) within very-short time scales. The population of isomeric states is a sensitive diagnostic method for characterization of the laser-driven secondary radiation sources.
期刊：
Monthly Notices of the Royal Astronomical Society,2024年529(2):1440-1449 ISSN：0035-8711
通讯作者：
Ye-Fei Yuan<&wdkj&>Wenbin Lin
作者机构：
School of Mathematics and Physics, University of South China , Hengyang 421001 , China;School of Physical Science and Technology, Southwest Jiaotong University , Chengdu 610031 , China;School of Nuclear Science and Technology, University of South China , Hengyang 421001 , China;School of Astronomy and Space Science, University of Science and Technology of China , Hefei 230026 , China;CAS Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China , Hefei 230026 , China
通讯机构：
[Ye-Fei Yuan; Wenbin Lin] S;School of Mathematics and Physics, University of South China , Hengyang 421001 , China<&wdkj&>School of Physical Science and Technology, Southwest Jiaotong University , Chengdu 610031 , China<&wdkj&>School of Astronomy and Space Science, University of Science and Technology of China , Hefei 230026 , China<&wdkj&>CAS Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China , Hefei 230026 , China
关键词：
methods: numerical;stars: kinematics and dynamics;Galaxy: centre;Galaxy: kinematics and dynamics;transients: tidal disruption events
摘要：
In the centres of galaxies, stars that orbit supermassive black hole binaries (SMBHBs) can undergo tidal disruptions due to the Lidov–Kozai mechanism. Nevertheless, most previous researches have predominantly focused on full tidal disruption events (FTDEs). In this study, we employ N-body simulations to investigate partial tidal disruption events (PTDEs) induced by intermediate-mass black holes (IMBHs) in SMBH–IMBH binaries, taking into account consideration the IMBH’s mass, semimajor axis, and eccentricity of the outer orbit. Our findings indicate that, in comparison to FTDEs, the majority of tidal disruption events are actually PTDEs. Furthermore, we find that a significant number of stars experiencing partial disruption ultimately get captured by the IMBH, potentially leading to repeating flares. By comparing the period of the periodic eruptions observed in ASASSN-14ko, we find that PTDEs in a specific SMBH–IMBH binary system can align with the observed period if the SMBH has a mass of |$10^7\rm {\ M_\odot }$|, the IMBH has a mass smaller than approximately |$10^5\rm {\ M_\odot }$|, the eccentricity of the SMBH–IMBH binary exceeds approximately 0.5, and the semimajor axis of the SMBH–IMBH binary is larger than approximately 0.001 pc. Moreover, our model effectively accounts for the observed period derivative for ASASSN-14ko (|$\dot{P}=-0.0026\pm 0.0006$|), and our results also imply that some quasi-periodic eruptions may be attributed to PTDEs occurring around SMBH–IMBH binaries.
摘要：
The GECAM series of satellites utilizes LaBr
$$_3$$
(Ce), LaBr
$$_3$$
(Ce,Sr), and NaI(Tl) crystals as sensitive materials for gamma-ray detectors (GRDs). To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E–C relationship, comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons, radioactive sources, and mono-energetic X-rays. The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences, with all three crystals presenting a higher nonlinearity for X/
$$\gamma$$
-rays than for Compton electrons. Despite the LaBr
$$_3$$
(Ce) and LaBr
$$_3$$
(Ce,Sr) crystals having higher absolute light yields, they exhibited a noticeable nonlinear decrease in the light yield, especially at energies below 400 keV. The NaI(Tl) crystal demonstrated an "excess" light output in the 6–200 keV range, reaching a maximum "excess" of 9.2% at 30 keV in the X-ray testing and up to 15.5% at 14 keV during Compton electron testing, indicating a significant advantage in the detection of low-energy gamma rays. Furthermore, we explored the underlying causes of the observed nonlinearity in these crystals. This study not only elucidates the detector responses of GECAM, but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.
期刊：
Chemical Communications,2024年60(21):2906-2909 ISSN：1359-7345
通讯作者：
Xie, ZY;Wu, XW;Liao, JJ;Wu, Xiongwei;Ling, W
作者机构：
[Wu, Xuewen; Xie, Zhiyong] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Wu, Xuewen; Xie, Zhiyong] Cent South Univ, Sci & Technol High Strength Struct Mat Lab, Changsha 410083, Peoples R China.;[Wu, Xiongwei; Wu, Xuewen; Wu, Saixiang; Wu, XW; Yin, Xingrong; Liu, Jun] Hunan Prov YinFeng New Energy Co Ltd, Changsha 410000, Peoples R China.;[Liao, Jingjing] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Wu, Xiongwei; Ling, Wei; Wu, XW; Ling, W; Liu, Jun] Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.
通讯机构：
[Xie, ZY ] C;[Wu, XW; Wu, XW ; Ling, W ] H;[Liao, JJ ] U;Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;Cent South Univ, Sci & Technol High Strength Struct Mat Lab, Changsha 410083, Peoples R China.
摘要：
A phosphoric acid additive with an optimal concentration of 0.1 M can vastly promote the diffusion kinetics of the redox reaction between V(iv) and V(v) without a significant decline in energy efficiency for 300 cycles, and maintain the high-temperature stability (55 degrees C) of an electrolyte at a high state of charge (SOC) of 70% over the course of 30 days. A phosphoric acid additive with an optimal concentration of 0.1 M can maintain the high-temperature stability (55 degrees C) of an electrolyte at a high state of charge (SOC) of 70% over the course of 30 days.
期刊：
Chemical Engineering Journal,2024年485:150022 ISSN：1385-8947
通讯作者：
Shunyan Ning<&wdkj&>Lifeng Chen
作者机构：
[Linyuan Liao; Xuexiang He; Lidan Lv; Wenlong Li] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China;Key Laboratory of Advanced Nuclear Energy Design and Safety, Ministry of Education, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China;School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China;[Jing Tang; Xiangbiao Yin; Shunyan Ning; Lifeng Chen] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China<&wdkj&>Key Laboratory of Advanced Nuclear Energy Design and Safety, Ministry of Education, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China;[Yuezhou Wei] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China<&wdkj&>School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China
通讯机构：
[Shunyan Ning; Lifeng Chen] S;School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China<&wdkj&>Key Laboratory of Advanced Nuclear Energy Design and Safety, Ministry of Education, University of South China, 28 Changsheng West Road, Hengyang 421001, PR China
摘要：
212Pb serves as one of the most important nuclides for targeted alpha therapy (TAT), with good potential in the treatment of malignant tumors. However, medical and clinical applications are seriously limited by its extremely short supply, which strongly depends on the acquisition of its parent nuclides such as 228Ra or 224Ra. To address this issue, we conducted a systematic investigation on the separation of trace radium from natural thorium using the ion exchange chromatography method, and a novel porous silica-based composite resin functionalized with sulfonic acid groups was prepared, characterized, and employed. Experimental results showed that the silica-supported resin was successfully prepared with the sulfonic acid groups, and possessed small particle size, mesoporous pore structure and large specific surface area. The resin exhibited high selectivity toward thorium compared with barium, and the separation factor reached 123 at low acidity and at low temperature. The resin demonstrated a fast adsorption speed and an excellent separation performance, and the adsorption mechanism was confirmed based on the ion exchange between the sodium carried and the target cations. On the basis, column experiments were further conducted and finally the separation of trace radium from thorium was realized using a small column filled with about 1.0 g resin. The chemical recovery of radium reached 97 %, and the decontamination factor for thorium exceeded 40,000. This work verifies the feasibility of directly extracting 228Ra and 224Ra from natural thorium using the sulfonic acid group functionalized materials in the dilute nitric acid solution, and presents an excellent material and systematic experimental data on the separation activities, rendering this study particularly significant.
关键词：
W-Y 2 O 3 matrix;Hydrogen diffusion;Nuclear thermal propulsion;Fuel loss
摘要：
The fissile fuel loss in tungsten (W) based ceramic-metal (Cermet) element used in nuclear thermal propulsion is of great importance. In this study, the W-Y2O3 composite matrix was manufactured tentatively by Spark Plasma Sintering (SPS) to relieve the fuel loss. Performance evaluation of hydrogen (H2) permeation and diffusion behaviors in the matrix was carried out by a gas permeation device. The results indicate that the diffusion coefficient of H2 in the pure W matrix is nearly 10 times larger than that in the W-Y2O3 matrix at a test temperature of 823 K. Based on the results, a careful investigation of the fuel loss mechanism of the Y2O3 dispersed W matrix was performed. SEM and TEM showed that the fine Y2O3 particles are distributed along grain boundaries of the W ternary-phase and present a distinct transition region of about 10 nm between the Y2O3 and W phases. In particular, the crystallographic orientation relationship suggests that a semi-coherent structure is formed at the W/Y2O3 phase interface: (0 1 −1) W || (1 0 −1) Y2O3 and [0 1 1] W || [1 1 1] Y2O3. This semi-coherent structure is favorable for binding the two phases together tightly, thus hindering the inward diffusion of H2 greatly. Moreover, the improved density and refined size of the W grains are achieved. Therefore, there is no doubt that the dispersion of Y2O3 is beneficial for lowering the H2 diffusion rate in the W matrix and thus reducing the fuel loss effectively. This work furthers our understanding of the key role of Y2O3 in the W matrix used in nuclear thermal propulsion.
作者：
Zi Chen;Xianggang Li;Haihua Liu;Weichuan Xu;Jiaye Yu;...
期刊：
Microporous and Mesoporous Materials,2024年370:113069 ISSN：1387-1811
通讯作者：
Jinlong Jiang<&wdkj&>Ping Mao
作者机构：
[Xianggang Li; Haihua Liu; Weichuan Xu; Jiaye Yu; Yuxin Zang; Guang Hu; Tao Hu; Jinlong Jiang; Ping Mao] Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian, 223003, China;[Yichang Pan] State Key Laboratory of Materials Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China;Jiangsu Hemings New Material Technology Co., LTD, Suqian, 223900, China;[Yuezhou Wei] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China;[Zi Chen] Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian, 223003, China<&wdkj&>State Key Laboratory of Materials Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China<&wdkj&>Jiangsu Hemings New Material Technology Co., LTD, Suqian, 223900, China
通讯机构：
[Jinlong Jiang; Ping Mao] K;Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian, 223003, China
摘要：
A novel and cost-effective approach was successfully developed for synthesizing high-performance zeolite 4A encapsulating magnetic particles (magnetic zeolite 4A) using kaolinite and red mud as raw materials via one-step combined activation-reduction and subsequent hydrothermal synthesis. The concurrent reduction of iron compounds in red mud to magnetic particles mainly composed of Fe3O4 during the thermal activation of kaolinite eliminated the need for a distinct red mud reduction process, thereby streamlining the synthesis and maximizing efficiency. The resulting product comprised highly crystalline zeolite 4A encapsulating magnetic particles derived from the red mud, avoiding oxidation and corrosion of the magnetic material in acidic solutions. A series of magnetic zeolite 4A (MZ) were obtained by introducing varying percentages of red mud and kaolinite, and their morphological, structural, magnetic and adsorption properties were investigated. The BET specific surface area of the obtained MZ-20 is 13.6 m2/g. MZ-20 (red mud: kaolinite mass percentage is 20%) displayed the maximum adsorption capacity of 172 mg/g for Sr(II). Within 1 h, 96.4% of the Sr(II) was removed. The adsorption kinetics and isotherms followed the pseudo-second-order and Langmuir models, respectively. Using a mixed 0.1 M NaCl and 0.1 M HCl solution as eluent, the magnetic adsorbent maintained high desorption and regeneration ratios along with stable magnetic properties after four adsorption-desorption cycles. In summary, the MZ-20 adsorbent exhibited high adsorption capacity, recyclability and excellent magnetic properties, making it a decontamination candidate for removing Sr(II) from radioactive wastewater.
期刊：
Journal of Environmental Management,2024年353:120283 ISSN：0301-4797
通讯作者：
Shunyan Ning<&wdkj&>Ji Wang
作者机构：
[Wang, Xinpeng; He, Chunlin; Fujita, Toyohisa; Wu, Kun; Zhong, Yilai; Li, Zengyuan] State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, and School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China;[Ning, Shunyan] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: ningshunyan@usc.edu.cn;[Wang, Ji] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: wangji_jenny@163.com;[Wei, Yuezhou; Hamza, Mohammed F; Yin, Xiangbiao; Chen, Lifeng] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China;[Wei, Yuezhou] School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, China
通讯机构：
[Shunyan Ning; Ji Wang] S;School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China
关键词：
Adsorption and separation;Co-Nd-Dy;DFT calculations;DPPA/CaALG;NdFeB
摘要：
The recovery of rare earth elements (REEs) including neodymium (Nd) and dysprosium (Dy) from NdFeB permanent magnets has become one of the main ways to solve the increased demand for rare earth. Herein, n-dodecyl phosphate (DPPA) was used for the first time as the adsorption functional group donor, sodium alginate as the substrate, and calcium chloride solution as the reactive solvent, a hybrid hydrogel adsorbent DPPA/CaALG was synthesized by sol-gel method for application in the adsorption and separation of Nd and Dy from the Co-Nd-Dy ternary system. SEM-EDS, and N(2) adsorption-desorption analysis showed the successful preparation of DDPA/CaALG with mesoporous structure. Batch experiments showed the superiority of the hybrid hydrogel for the good selective adsorption of Nd and Dy, such as large adsorption capacity (Nd: 162.5mg/g, Dy: 183.5mg/g), and no adsorption for Co. FT-IR, XPS showed that PO and P-O groups are involved in the adsorption process of Nd and Dy as electron acceptors, where the ion exchange of P-OH is dominant. Furthermore, the chemical properties of ligands and complexes were analyzed by Density Functional Theory (DFT) calculations and revealed their adsorption behaviors as well as the competition between different metal ions.
摘要：
The long-lived fission products (LLFPs) are one of the major impediments to the development of nuclear energy due to their longevity and toxicity. The fast neutron reactor, with its high neutron flux and excessed neutron, is a strong candidate for transmuting LLFPs. In this investigation, 79Se, 99Tc and 129I were selected as the representative nuclide of LLFPs, and then neutron moderators were loaded into the LLFPs assembly with LLFPs to evaluate the effect of different loading approaches on transmutation efficiency by the transmutation performance of LLFPs. The results show that the optimal loading strategy of moderator could increase the TR and SR with 2.35 (1.01) and 284.80 (151.11), 0.36 (0.28) and 8.06 (7.88), 1.69 (0.69) and 11.45 (7.80), respectively. It is suggested that it can transmute an additional 4500 g, 1000 g and 6600 g of these three LLFPs per year.
摘要：
A simple approach for preparing high-efficiency and cost-effective adsorbent to extract uranium in nuclear wastewater is essential for safeguarding the environment. This study introduces an easy procedure to synthesize phosphate-rich biochar (PS) from sawdust by treating it with phosphoric acid before carbonization (700 degrees C). The sample was characterized by SEM, FT-IR, BET and XPS, indicating that the PS700 exhibited a high concentration of phosphorous groups, high specific surface area and developed mesoporous structure. Subsequently, the effects of pH (optimal at pH 7), adsorption kinetics (fitted by quasi-second-order), and sorption isotherms (modeled by Langmuir) were investigated. The best uranium (VI) adsorption performance of PS700 is 808 mg g-1 at 40 degrees C and pH 7. In addition, PS700 shows remarkable selectivity and recyclability for uranium (VI). The sorption mechanism can be attributed to the uranium (VI) binding with phosphate groups on the surface of sorbent, which significantly improve its ability for uranium (VI) adsorption. This study displays a great application prospect of PS700 as innovative adsorbent for the efficient extraction of uranium (VI) from nuclear wastewater.
作者：
Long Gui;Yingming Song*;Xiaomeng Li;Weiwei Yuan
期刊：
Annals of Nuclear Energy,2024年201:110415 ISSN：0306-4549
通讯作者：
Yingming Song
作者机构：
[Long Gui; Xiaomeng Li] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;Nuclear Industry College, CNNC, Beijing 102618, China;[Weiwei Yuan] Radon Provincial Key Laboratory, University of South China, Hengyang 421001, China;[Yingming Song] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China<&wdkj&>Nuclear Industry College, CNNC, Beijing 102618, China
通讯机构：
[Yingming Song] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, China<&wdkj&>Nuclear Industry College, CNNC, Beijing 102618, China
摘要：
Researchers have utilized neural networks as agent models to predict shielded data sets for reactor shielding designs. However, previous models faced challenges related to unbalanced multi-scale characteristics in input and output data sets, resulting in significant generalization errors. Additionally, these models did not consider source term parameters like energy spectrum probability density distribution parameters and angle sine and cosine distribution parameters. To address these challenges, this study proposes an improved neural network model with the Swish-NNTA learning scheme. This learning scheme incorporates the high-performance Swish activation function and the enhanced Nadam-Nadamax Transition Algorithm (NNTA) learning algorithm. Experimental results demonstrate that the mean absolute percentage error (MAPE) for the upper Savannah shielding model is 0.748%, while the MAPE for the H.B.ROBINSON-2 PWR shielding model is 1.428%. The proposed shielding calculating agent model achieves higher accuracy and efficiency, presenting a promising solution for enhancing reactor shielding design and analysis.
摘要：
The phosphoric acid activated biochar adsorbent is recognized as a good candidate for application in efficient disposal of uranium-containing nuclear wastewaters. However, the production of high-efficiency biochars with typical characteristics of large specific surface area, hierarchically porous structure and abundant adsorption group remains a challenge. In this work, we report a new hydrogelation-carbonization technique to facilely produce phosphorus-doped biochar from pomelo peel and meantime provide new sights into the interaction mechanism of phosphoric acid groups with uranium ion. An interesting hydrogelation phenomenon is found when simply mixing the phosphoric acid solution and pomelo peel powder. The resulted hydrogel readily undergo carbonization to produce desired biochar. The biochar exhibits good uranium removal efficiency (up to 99 %) with a maximum adsorption capacity of 603 mg/g at 313 K. The distribution coefficient of uranium (VI) attains 10.8 L/g. The biochar undergoes five desorption-adsorption cycles with desorption and adsorption efficiencies above 95 %. It can be applied in fix-bed column for dynamic adsorption of uranium from uranium-containing solutions and real nuclear wastewater with an adsorption capacity over 422 mg/g. Rather than direct interaction with uranium ion, our experimental and computational results reveal that the surface phosphoric acid groups initially undergo in-situ ionization to produce phosphonates and the complexation of phosphonate with uranium ion results in effective uranium adsorption. This work demonstrates the high efficiency of pomelo peel biochar for disposal of uranium-containing nuclear wastewater, and offers new insights into the mechanism of uranium adsorption on the adsorbents containing phosphoric acid and phosphonate groups.
作者机构：
[Toyohisa Fujita; kun wu; Sizhi Xu; Yilai Zhong; Zhengyuan Li] State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, and School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China;[Ning shunyan; Yuezhou Wei; Mohammed F. Hamza; Xiangbiao Yin; Lifeng Chen] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, P.R. China. ningshunyan@usc.edu.cn;[Yuezhou Wei] School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
通讯机构：
[Ning, Shunyan] S;School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, P.R. China.
摘要：
Accurate separation and efficient recovery of platinum group metals (PGMs, mainly Ru, Rh and Pd) from high level liquid waste (HLLW) is a good choice for clean production and sustainable development of nuclear energy. Herein a novel SDB polymer modified silica-based amine-functionalized composite (dNbpy/SiO(2)-P) was synthesized for the separation and recovery of PGMs. Laser particle size analysis and BET results clarified the regular spherical and highly interconnected mesoporous structure of dNbpy/SiO(2)-P which is critical for the separation of PGMs. The removal percent of PGMs were over 99% on the optimized conditions. In addition, dNbpy/SiO(2)-P showed excellent selectivity (SFPd/M > 3805, SFRu/M > 1705, SFRh/M > 336) and repeatability (≥5). Interestingly, based on the different adsorption and desorption kinetics of PGMs, a double-column strategy is designed to solve the challenge of separating and recovering PGMs from HLLW. The enrichment factors of Pd(II), Ru(III) and Rh(III) reached 36.7, 8.2, and 1.2. The adsorption of PGMs was coordination mechanism and required the involvement of NO(3)(-) to maintain charge balance. The specific distribution of elements within the adsorbents and the changes in valence state were analyzed using depth-profiling XPS. Both depth-profiling XPS results and slope analysis revealed that the complex of dNbpy and PGMs is a 1 : 1 coordination structure. Overall, this work fills the gap that PGMs cannot be effectively separated and enriched from HLLW.
期刊：
Nuclear Engineering and Technology,2024年56(1):160-166 ISSN：1738-5733
通讯作者：
Cao, JJ
作者机构：
[Zhang, Biao; Zhang, Yulong; Chen, Wei; Li, Xiaomeng; Zheng, Xiaochang; Cao, Jinjia; Song, Yingming] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Lin, Shuang] China Nucl Power Engn Co Ltd, Instrument Control Design Inst Beijing, Nucl Engn Res & Design Inst, Beijing 100142, Peoples R China.
通讯机构：
[Cao, JJ ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
Radiation fields of multiple gamma source;Optimized IDW;MAPE;Geant4;Decommissioning of nuclear facilities
摘要：
The inversion of radiation field distribution is of great significance in the decommissioning sites of nuclear facilities. However, the radiation fields often contain multiple mixtures of radionuclides, making the inversion extremely difficult and posing a huge challenge. Many radiation field reconstruction methods, such as Kriging algorithm and neural network, can not solve this problem perfectly. To address this issue, this paper proposes an optimized inverse distance weighted (IDW) interpolation algorithm for reconstructing the gamma radiation field. The algorithm corrects the difference between the experimental and simulated scenarios, and the data is preprocessed with normalization to improve accuracy. The experiment involves setting up gamma radiation fields of three Co-60 radioactive sources and verifying them by using the optimized IDW algorithm. The results show that the mean absolute percentage error (MAPE) of the reconstruction result obtained by using the optimized IDW algorithm is 16.0%, which is significantly better than the results obtained by using the Kriging method. Importantly, the optimized IDW algorithm is suitable for radiation scenarios with multiple radioactive sources, providing an effective method for obtaining radiation field distribution in nuclear facility decommissioning engineering.
作者机构：
[Xu-Dong Zhao] School of Physics and Electronics, Hunan University, Changsha 410082, China;[Fei Mao] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;College of Materials Science and Engineering, Hunan University, Changsha 410082, China;[Huiqiu Deng] School of Physics and Electronics, Hunan University, Changsha 410082, China<&wdkj&>College of Materials Science and Engineering, Hunan University, Changsha 410082, China
通讯机构：
[Fei Mao; Huiqiu Deng] S;School of Physics and Electronics, Hunan University, Changsha 410082, China<&wdkj&>College of Materials Science and Engineering, Hunan University, Changsha 410082, China<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang 421001, China
摘要：
The electronic stopping power and charge state of protons and helium ions irradiating iron under both channeling and off-channeling geometries are studied by first-principles molecular dynamics. Using real-time time-dependent density functional theory, the inner-electron excitation of iron under ion irradiation is explored. The calculated electronic stopping powers, which take into account the effects of inner-electron excitation, were found to be in good agreement with experimental data. To further investigate the charges attracted by the projectiles moving in iron, we introduced a modified method to decompose the charges into the occupations of the respective projectile orbitals. When the projectile ion moves along off-channeling trajectories, the orbital distribution of the charges attracted by protons is found to be unstable, while that of helium ions remains relatively stable. However, it is worth noting that the orbital distribution differs between the channeling and off-channeling cases for both protons and helium ions. Overall, our research provides insight into the electron capture behavior of protons and helium ions as they traverse through iron.
