Article
Materials Science, Multidisciplinary
M. W. D. Cooper, K. A. Gamble, L. Capolungo, C. Matthews, D. A. Andersson, B. Beeler, C. R. Stanek, K. Metzger
Summary: U3Si2, an advanced fuel candidate with high fissile density and thermal properties, has data gaps in thermophysical and thermomechanical properties. This study used DFT and MD simulations to predict point defect concentrations under irradiation, informing a creep model based on diffusional creep and dislocation creep, which compares well with experimental data and has been implemented in a fuel performance code. Demonstrations show negligible creep in U3Si2 due to its high thermal conductivity at low reactor temperatures.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Environmental Sciences
Kirk J. Cantrell, Guohui Wang, Alexandre Mitroshkov, Justin D. Lowrey
Summary: A method for measuring the adsorption of trace noble gas elements to the surfaces of geologic materials was developed and tested. It was found that noble gas adsorption increases with increasing atomic mass and decreasing temperature, and also increases non-linearly with increasing gas concentration.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY
(2022)
Article
Chemistry, Physical
Isabel Nitzke, Jadran Vrabec
Summary: Generalized expressions for thermodynamic properties in terms of ensemble averages are discussed for adiabatic and isothermal ensembles. They are implemented in the simulation code ms2 and validated by Monte Carlo simulations for the Lennard-Jones fluid. A comparison of the eight statistical ensembles regarding size scaling behavior, convergence, and stability is provided for state points throughout the homogeneous fluid region. The resulting data are in good agreement but differ in their statistical distributions. In closed systems, the statistical quality of the data is better than in open systems. Overall, the microcanonical ensemble performs best.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Physics, Multidisciplinary
Abbas Gholami, Rupert Klein, Luigi Delle Site
Summary: This article introduces a novel approach that combines the adaptive resolution scheme with a fluctuating hydrodynamics solver to couple the particle domain with its embedding environment. The algorithm allows for a physically consistent exchange of matter and energy and has been validated through numerical tests. Compared to previous algorithms, this approach can efficiently handle complex molecular systems.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Theo Beigbeder, Emeric Bourasseau, Michael Rushton
Summary: In-depth understanding of nuclear fuel behaviour is crucial for preventing severe accidents. Evaluation of existing interatomic potentials and determination of new parameters can improve knowledge on liquid mixtures and achieve good agreement with experimental data at high temperatures.
MOLECULAR SIMULATION
(2021)
Article
Materials Science, Multidisciplinary
J. L. Wormald, A. I. Hawari
Summary: In fission-based nuclear reactors, the interaction between fission fragments and electronic excitations leads to thermalization and the formation of high temperature thermal spikes. This promotes atomic mobility and lattice defects formation. A multigroup model for electron energy transport is developed to simulate fission energy deposition in nuclear fuel. The results show reasonable agreement with experimental trends and provide insights into fission effects.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Shiddartha Paul, Daniel Schwen, Michael P. Short, Kasra Momeni
Summary: In this study, a modified embedded-atom method (MEAM) potential was developed to investigate the atomistic mechanisms of high-temperature application material T91. The potential showed good agreement with experimental and theoretical results in terms of elastic constants, thermal expansion, and self-diffusion coefficients. This potential provides valuable insights for the design of alloys that can withstand harsh environments.
Article
Physics, Fluids & Plasmas
Markus Kulossa, Philipp Marienhagen, Joachim Wagner
Summary: This study provides the second to sixth-order virial coefficients of hard hyperspherocylinders in four dimensions, and compares them with the geometric calculations based on the aspect ratio.
Article
Physics, Nuclear
Yijie Wang, Fenhai Guan, Xinyue Diao, Mengting Wan, Yuhao Qin, Zhi Qin, Qianghua Wu, Dong Guo, Dawei Si, Sheng Xiao, Boyuan Zhang, Yaopeng Zhang, Baiting Tian, Xianglun Wei, Herun Yang, Peng Ma, Rongjiang Hu, Limin Duan, Fangfang Duan, Qiang Hu, Junbing Ma, Shiwei Xu, Zhen Bai, Yanyun Yang, Jiansong Wang, Wenbo Liu, Wanqing Su, Xiaobao Wei, Chun-Wang Ma, Xinxiang Li, Hongwei Wang, Fangyuan Wang, Yingxun Zhang, Michal Warda, Arthur Dobrowolski, Bozena Nerlo-Pomorska, Krzysztof Pomorski, Li Ou, Zhigang Xiao
Summary: Thermodynamic and chemical two-body correlations of isotope-resolved clusters were measured in 86Kr + 208Pb reactions at 25 MeV/u. Analysis of the yield and kinetic variables of A = 3 isobars were done in coincidence with intermediate mass fragments of 6 A 11. The yield ratios of t/3He correlated reversely with the neutron-to-proton ratio N/Z of the intermediate mass fragments, showing the ping-pong modality of the emitted particles' N/Z. The comparison to transport model calculations was discussed.
Article
Multidisciplinary Sciences
T. Doppner, M. Bethkenhagen, D. Kraus, P. Neumayer, D. A. Chapman, B. Bachmann, R. A. Baggott, M. P. Bohme, L. Divol, R. W. Falcone, L. B. Fletcher, O. L. Landen, M. J. MacDonald, A. M. Saunders, M. Schorner, P. A. Sterne, J. Vorberger, B. B. L. Witte, A. Yi, R. Redmer, S. H. Glenzer, D. O. Gericke
Summary: This article reports on an experiment that creates and diagnoses matter at pressures exceeding three gigabars. The experiment shows the presence of quantum-degenerate electrons and strongly reduced elastic scattering under extreme conditions.
Article
Geochemistry & Geophysics
Yacong (Brooke) Zhou, William A. Goddard, Paul D. Asimow
Summary: In this study, the accuracy of the Mie-Gruneisen approximation was investigated for describing the thermal equation of state of a silicate liquid. By tuning an empirical force-field and proposing a new model form with additional free parameters, significant improvements in fitting sparse shock wave experiment data were achieved.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Multidisciplinary Sciences
Rita Parai
Summary: Primordial volatiles were delivered to the Earth's mantle during its formation. This study used isotopic ratios to determine the proportions of volatile elements in the mantle plume and upper mantle, finding that the plume mantle had lower concentrations of volatiles compared to the upper mantle at the end of formation. This finding is crucial for understanding the noble gas signatures in mantle rocks.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Materials Science, Multidisciplinary
Conor O. T. Galvin, Masahiko Machida, Hiroki Nakamura, David A. Andersson, Michael W. D. Cooper
Summary: Molecular dynamics simulations were used to predict the specific heat capacity of Gd-doped PuO2, UO2, and (U, Pu)O2 MOx, taking into account two charge compensation mechanisms - oxygen vacancy formation and the oxidation of U 4+ to U 5+. The results show a reduction in peak height of specific heat capacity for each composition with the addition of Gd3+.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Quantum Science & Technology
Or Katz, Roy Shaham, Ofer Firstenberg
Summary: An ensemble of noble-gas nuclear spins is a unique quantum system that can maintain coherence for long periods of time at room temperature and above. By colliding with alkali-metal atoms, these spins can interface with other quantum systems while preserving their coherence. This allows for efficient, controllable, and deterministic entanglement and exchange of excitations.
Article
Mechanics
Shenghong Huang, Jiawei Zhang, Juchun Ding, Xisheng Luo
Summary: In this study, the Richtmyer-Meshkov instability (RMI) under extreme impacting conditions is investigated using molecular dynamics (MD) simulation. The results show that ionization occurs when the material is strongly loaded, resulting in the formation of a quasi-steady electron/ion separation zone across the shock front. This separation zone propagates at the same velocity as the shock wave and remains approximately constant in width and strength. Based on these findings, a simple charge distribution profile is proposed for microscopic RMI with ionization, and an analytical model for interface acceleration can be derived. When a nondimensional parameter (eta) exceeds a certain value, the charge density distribution is similar to that of macroscopic RMI with ionization, and an acceleration model for macroscopic RMI can be developed. The validity of the model is confirmed through large-scale MD simulations and experimental results.
Article
Materials Science, Multidisciplinary
Liuming Wei, Jingwen Li, Yonggang Li, Qirong Zheng, Fan Cheng, Chuanguo Zhang, Jingyu Li, Gaofeng Zhao, Zhi Zeng
Summary: This study investigates the influence of He-V complexes on H behaviors on different W surfaces using DFT calculations. The results show that H dissolution is most difficult but H trapping is easiest on the W (110) surface, while the opposite is true on the W (111) surface. Moreover, the presence of He-V complexes increases the difficulty of H diffusion from bulk to surface and desorption.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yan Meng, Song Zeng, Chen Chen, Chaowen Zhu, Huahai Shen, Xiaosong Zhou, Xiaochun Han
Summary: The characteristics of magnetron sputtered Cr coatings vary with different temperature, bias voltage, and pressure. Coatings with random orientation, good crystallinity, and small grain size exhibit favorable oxidation behavior, while coatings with strong (200) texture, poor crystallinity, and large grains have many intrinsic defects that are detrimental to the protection property of the Cr coatings.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Xinyuan Xu, Zefeng Yu, Wei-Ying Chen, Aiping Chen, Arthur Motta, Xing Wang
Summary: This study presents an automated approach for characterizing grain morphology in TEM images recorded during ion irradiation. By combining a machine learning model and a computer vision algorithm, comparable results to human analysis can be achieved with significantly reduced analysis time. Researchers can train their own models following the procedures described in this study to automate grain morphology analysis of their own TEM images.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Shihao Wu, Dong Wang, Yapei Zhang, Koji Okamoto, Marco Pellegrini, Wenxi Tian, Suizheng Qiu, G. H. Su
Summary: The oxidation and degradation mechanisms of Cr coating on Zr alloy cladding under high temperature steam atmosphere are summarized, and a mathematical analysis model is established to predict the changes in coating thickness. The model is applied in the analysis of structure evolution under different conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
V. Diaz-Mena, J. de Prado, M. Roldan, I. Izaguirre, M. Sanchez, M. Rieth, A. Urena
Summary: The brazeability of a cupronickel alloy was evaluated as a filler alloy for high-temperature joining of tungsten to steel. The study investigated the brazing conditions and the impact of the selected filler on the joint quality using numerical software. The results showed different metallurgical interactions and diffusion phenomena between the filler alloy and the base materials at different temperatures. The study emphasized the importance of selecting a suitable filler to mitigate residual stresses in the joints.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Pengcheng Zhu, Yajie Zhao, Yan-Ru Lin, Jean Henry, Steven J. Zinkle
Summary: This study investigates the effect of heavy-ion irradiation on radiation hardening in high-purity binary alloy Fe18Cr. Nanoindentation testing and high-quality TEM imaging were conducted to extract hardness and microstructure information. The strength factor was accurately calculated based on the detailed TEM characterization of irradiated microstructures, and a refined hardening superposition method was applied to quantify the mechanical properties of ion-irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Bin Wu, Haixia Ning, Hanzhen Zhu, Jianjun Chen, Kang Wang, Daiyu Zhang, Fu Wang, Qilong Liao
Summary: This study discusses the effects of ZrO2 and B2O3 on the phase composition and properties of SAP-based glass-ceramics. The results show that ZrO2 addition improves the formation of NZP phase while restricting the crystallization of AlPO4 phases. The correct ratios of ZrO2 and B2O3 allow only the formation of NZP phase within the SAP glass.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Hwasung Yeom, Greg Johnson, Benjamin Maier, Tyler Dabney, Kumar Sridharan
Summary: Cr-Nb bilayer coatings were developed using cold spray deposition to improve the limiting operational temperature of Cr-coated Zr-alloy system. The coatings exhibited outstanding oxidation resistance at high temperatures and formed continuous intermetallic compound layers at the interfaces.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Padhraic L. Mulligan, Andrew T. Nelson, Chad M. Parish, Patrick A. Champlin, Xiang Chen, Daniel Morrall, Jason M. Harp
Summary: Environmental barrier coatings are being developed to reduce oxidation and embrittlement in Zr-based materials. Chromium nitride is a candidate for this application, but understanding its impact on irradiation-induced creep and microstructure is critical.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Dexuan Yan, Xinlei Cao, Ke Shen
Summary: This study investigated the purification mechanism of polycrystalline graphite by comparing IG-11 graphite with IG-110 nuclear grade graphite. The analysis revealed that metallic impurities in IG-11 were primarily segregated within graphite porosities, while IG-110 demonstrated a significant reduction in impurities. This research contributes to the development of innovative graphite purification techniques for greater purity and stronger oxidation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Wei Xu, Wei Peng, Lei Shi, Qi Sun
Summary: This paper investigates the oxidation and shape evolution of matrix graphite in high temperature gas-cooled reactors during air-ingress accidents. A reaction kinetics model is established and computational fluid dynamics with a dynamic mesh method is used to simulate the oxidation process. The results show that the geometric shape of graphite changes significantly with increasing flow rate, and the graphite pebbles tend to form a structure with a narrow front and wide tail.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Allison Harward, Casey Elliott, Michael Shaltry, Krista Carlson, Tae-Sic Yoo, Guy Fredrickson, Michael Patterson, Michael F. Simpson
Summary: This paper investigates the hygroscopic properties of eutectic LiCl-KCl absorbed into zeolite-4A. The study finds that water absorption and corrosion worsen with increasing salt loading. It also suggests that the salt can be stored in a non-inert atmosphere for a certain period of time.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Takaaki Koyanagi, Xunxiang Hu, Christian M. Petrie, Gyanender Singh, Caen Ang, Christian P. Deck, Weon-Ju Kim, Daejong Kim, James Braun, Yutai Katoh
Summary: This study provides critical experimental data on the effects of irradiation on the hermeticity of SiC composite cladding, finding that irradiation can cause a decrease in hermeticity and cracking, and coating the outer surface can mitigate the cracking issue.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
S. Krat, A. Prishvitsyn, Yu. Gasparyan
Summary: This study proposes a probabilistic and diffusion-based model to describe the co-deposition of multiple hydrogen isotopes with slowly grown metal layers. The model calculates the relative concentrations of different hydrogen isotopes in the co-deposited metal layers. It is found that if hydrogen isotopes have different detrapping energies, only the isotope with the highest detrapping energy shows a monotonic decrease in concentration with deposition temperature. Furthermore, the study evaluates the uncertainty of tritium concentration in the co-deposited layer based on the uncertainty in detrapping energy of tritium and deuterium, predicting a >10% tritium concentration uncertainty for a 0.01 eV difference.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Tijo Vazhappilly, Arup Kumar Pathak
Summary: This study investigates the effect of Ce atom substitution in UO2 on its thermophysical properties using density functional theory. The results show that the Ce substitution levels and the oxidation state of Ce/U atoms strongly influence the band structure and specific heat capacity of the UO2 lattice. These findings provide important insights into the fuel properties of UO2 under reactor conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)