Brodie S. Barth , Teagan F.M. Sweet , Avery L. Wood , Peter C. Burns , Andrew Miskowiec , Tyler L. Spano
{"title":"Raman spectroscopic investigation of UCl4","authors":"Brodie S. Barth , Teagan F.M. Sweet , Avery L. Wood , Peter C. Burns , Andrew Miskowiec , Tyler L. Spano","doi":"10.1016/j.jnucmat.2025.156129","DOIUrl":"10.1016/j.jnucmat.2025.156129","url":null,"abstract":"<div><div>Uranium chloride salts are a proposed fuel source for molten salt reactors (MSRs). However, despite their relevance to nuclear energy, they remain understudied, in part because of their air and moisture sensitivity. This work provides the first Raman spectra of UCl<sub>4</sub> from 45 to 3200 cm<sup>−1</sup> collected with 532 and 785 nm excitation sources as well as the assignment of 10 identified peaks to their respective vibrational modes. These Raman bands are compared to those for isostructural ThCl<sub>4</sub>, the compositionally related UCl<sub>3</sub>, and the computed Raman bands for UCl<sub>4</sub> from local vibrational mode analysis. The observed spectrum of UCl<sub>4</sub> is in accord with that of ThCl<sub>4</sub> and the computed spectra of UCl<sub>4</sub>. We posit that the observed differences between the spectra of UCl<sub>4</sub> and UCl<sub>3</sub> are useful in differentiating these species for applications such as in situ monitoring of MSR operations.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156129"},"PeriodicalIF":3.2,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ShuLong Wen , XiangYang Wang , Min Pan , HuiQiu Deng
{"title":"Synergistic trapping and desorption effects of vacancy and heterogeneous interface on helium in W-TiC alloys by first-principles calculations","authors":"ShuLong Wen , XiangYang Wang , Min Pan , HuiQiu Deng","doi":"10.1016/j.jnucmat.2025.156128","DOIUrl":"10.1016/j.jnucmat.2025.156128","url":null,"abstract":"<div><div>The synergistic trapping effect of vacancies and the W/TiC interface on helium, as well as the desorption behaviors of helium at the W/TiC interface with and without vacancies were investigated using first-principles calculations. The stability of interface structures with multiple interfacial orientations was assessed through the work of separation. Building on this, the thermodynamic stability of vacancies near the interface and their trapping effect on helium were examined. The presence of these vacancies significantly hindered the absorption of helium at the interface. Helium initially accumulated at vacancies near the interface, forming small Vac-<em>n</em>He clusters. As the number of captured helium atoms increased, helium became more prone to capture by the interface, thereby inhibiting the growth of Vac-<em>n</em>He clusters. The nearest-neighbor and second-nearest-neighbor vacancies near the interface together with the interface formed community and co-solvent structures, respectively. These structures can effectively promote the interface's ability to trap helium within bulk W, compared to the pure interface. The desorption temperatures of helium at the W/TiC interface with and without vacancy range from 1060 K to 1580 K and from 900 K to 1100 K, respectively. The presence of vacancies significantly elevated the desorption temperature of helium at the interface. These research findings contribute to a deeper understanding of the nucleation and growth mechanisms of helium bubbles, as well as the desorption of helium at the W/TiC interface.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156128"},"PeriodicalIF":3.2,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhonghua Lu , Yanli Shi , Yuchen Liu , Huanhuan Liu , Xiuling Wang , Cong Zhang , Gaoyuan Wang , Jianqi Qi , Tiecheng Lu
{"title":"Lowered tritium diffusivity by decreased site density along Li2TiO3 (001) twin boundary","authors":"Zhonghua Lu , Yanli Shi , Yuchen Liu , Huanhuan Liu , Xiuling Wang , Cong Zhang , Gaoyuan Wang , Jianqi Qi , Tiecheng Lu","doi":"10.1016/j.jnucmat.2025.156127","DOIUrl":"10.1016/j.jnucmat.2025.156127","url":null,"abstract":"<div><div>Li<sub>2</sub>TiO<sub>3</sub> is a prominent tritium breeder material with significant potential in the design of nuclear fusion reactors. Given that tritium recovery is closely related to its behavior at grain boundaries (GBs), understanding the dynamics is critical for optimizing the tritium release performance of the breeder material. In this work, we investigate the diffusion of tritium at the Li<sub>2</sub>TiO<sub>3</sub> (001) twin GB with density functional theory and kinetic Monte Carlo. Tritium segregation sites are identified and local migration paths between these sites are analyzed. The segregation energies are in the range of -0.43 ∼ 0.06 eV. The activation energies for tritium migration along the <strong><em>a</em></strong>-axis and the <strong><em>b</em></strong>-axis of the GB are 0.54 eV and 0.56 eV, respectively. The diffusion coefficient for tritium along the GB is estimated to be 1.97 × 10<sup>–7</sup> exp(-0.45 eV/K<sub>B</sub><em>T</em>) m<sup>2</sup>/s. The GB affects tritium diffusivity mainly by raising the activation energy along the <strong><em>b</em></strong>-axis, which consequently lowers the diffusivity by less than one order of magnitude within the 300∼1200 K temperature range compared to the bulk. The decreased tritium site density at the GB compared to bulk is proposed to be the reason for the modified diffusion behaviors by the GB.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156127"},"PeriodicalIF":3.2,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hybrid machine learning with optimization algorithm and resampling method for predicting the swelling rate of irradiated type 316 stainless steels","authors":"Van-Thanh Pham, Kyoon-Ho Cha, Jong-Sung Kim","doi":"10.1016/j.jnucmat.2025.156126","DOIUrl":"10.1016/j.jnucmat.2025.156126","url":null,"abstract":"<div><div>This study introduces innovative hybrid machine learning (ML) models that integrate seven state-of-the-art ML algorithms with the WEighted Relevance-based Combination Strategy (WERCS) and the Fire Hawks Optimizer (FHO) algorithm to predict the swelling rate of irradiated type 316 stainless steel (316 SS). A database of 333 experimental samples with 19 selected input features is utilized for model development. The WERCS method is used to address dataset limitations related to size and imbalance, while hyperparameter optimization is efficiently performed using cross-validation combined with the FHO algorithm. Performance evaluation across multiple metrics identifies the WERCS-FHO<img>CGB model, which combines WERCS, FHO, and categorical gradient boosting (CGB), as the most accurate for swelling rate prediction. To enhance interpretability, the Shapley Additive Explanations method is applied to analyze the global and local contributions of input variables, highlighting irradiation fluence, pre-irradiation fluence, dislocation density, temperature, and Si (wt.%) as the most influential factors. Additionally, the impact of these key parameters on the swelling rate of irradiated 316 SS is thoroughly investigated. Finally, a user-friendly graphical interface tool and web application are developed based on the WERCS-FHO-CGB model, providing a practical and cost-effective solution for predicting the swelling rate of irradiated 316 SS.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156126"},"PeriodicalIF":3.2,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kyle Williams, Lavanya Upadhyaya, Nathaniel Thomas, Michenna Allen, Lin Shao
{"title":"Corrosion susceptibility and chromium loss in Austenitic steels and Nickel-based alloys in molten FLiNaK at 700 °C","authors":"Kyle Williams, Lavanya Upadhyaya, Nathaniel Thomas, Michenna Allen, Lin Shao","doi":"10.1016/j.jnucmat.2025.156123","DOIUrl":"10.1016/j.jnucmat.2025.156123","url":null,"abstract":"<div><div>A comparative study was conducted to evaluate the corrosion susceptibility of 316L, 316H, Ni 200, Inconel 625, and Hastelloy N in molten FLiNaK at 700 °C for 100 h. Top-view and cross-sectional scanning electron microscopy (SEM) imaging, combined with energy-dispersive X-ray spectroscopy (EDS) mapping, was performed to investigate microstructural and compositional changes. SEM images were further processed by introducing a contrast threshold to map cavity distribution. Using EDS mapping, intergranular and intragranular Cr loss were separately characterized. The ranking of mass loss after corrosion, from highest to lowest, is as follows: 316H > 316L > Inconel 625 > Hastelloy N > Ni 200. Cr loss was found to be correlated with Mo concentration, in agreement with many previous studies, with higher Mo content resulting in reduced Cr loss. On the other hand, there is no evidence that the high carbon content in 316H enhances corrosion resistance. The relatively low solubility of carbon in austenite at the testing temperature limits the amount of dissolved carbon. Therefore, the carbon-retarded vacancy diffusion, and consequently the reduced Cr diffusion, were not observed.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156123"},"PeriodicalIF":3.2,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144988951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiuguo Deng , Wei Zhang , Yudong Li , Hao Liu , Rongshuo Wang , Yining Ren , Yue Liu , Ning Liu , Ziyao Long , Jijun Yang
{"title":"Corrosion resistance of Ta-based TaCrWNbTi refractory high–entropy alloy coating in static lead–bismuth eutectic at 550 and 650℃ after 1000h","authors":"Jiuguo Deng , Wei Zhang , Yudong Li , Hao Liu , Rongshuo Wang , Yining Ren , Yue Liu , Ning Liu , Ziyao Long , Jijun Yang","doi":"10.1016/j.jnucmat.2025.156118","DOIUrl":"10.1016/j.jnucmat.2025.156118","url":null,"abstract":"<div><div>Herein, a Ta-based TaCrWNbTi refractory high-entropy alloy coating (RHEA) coating was designed for retarding lead-bismuth eutectic (LBE) corrosion. The coating was fabricated by magnetron sputtering technology and then exposed to static LBE at 550℃ and 650℃ for 1000 h. The performance was analyzed by SEM, GIXRD, TEM, and scratch test. The as-deposited coating exhibited a double-layer structure with upper BCC phase and lower amorphous structure. After LBE corrosion, an oxide layer (mainly Fe-oxide) was formed at the surface. The coating maintained good structural stability without apparent element consumption, and the interior of the coating had a low oxidization level. Additionally, the bonding strength of the coating was substantially enhanced due to the interdiffusion of elements between the coating and the substrate. These characteristics indicate that the coating possessed good corrosion resistance compared to FeCrAlW, TiNbZrMoV, CrNbZrMoV, TiCrZrMoV, TiNbZrMoCr, AlCrFeMoTi and AlTiCrFe coatings. However, the coating failed to prevent the outward diffusion of Fe. This is the current drawback of the coating, which stems from the insufficient barrier effect of the oxide layer. After solving this problem, it can be considered to be applied to nuclear power systems. This study indicates that structural stability, antioxidant properties and good adhesion are the key factors for corrosion-resistant coatings. For the HEA coating, improving the quality of the formed oxide layer may be one of the most critical measures for enhancing its corrosion resistance in the future.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156118"},"PeriodicalIF":3.2,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144988950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yulin Wei , Xiaoyue Li , Linfeng Ye , Ping Peng , Min Liu
{"title":"Enhanced He irradiation damage resistance at 850 °C of Ni-based alloy via W substitution for Mo: Experiments and DFT calculations","authors":"Yulin Wei , Xiaoyue Li , Linfeng Ye , Ping Peng , Min Liu","doi":"10.1016/j.jnucmat.2025.156122","DOIUrl":"10.1016/j.jnucmat.2025.156122","url":null,"abstract":"<div><div>The Ni-26W-6Cr alloy was subjected to He ion irradiation at 850 °C with gradient-fluence (1, 3, and 5 × 10¹⁶ ions/cm²), and the defect evolution and hardening behavior were characterized. Theoretical analyses were then conducted, including: He bubble pressure estimation via Young-Laplace and equation of state, hardness increment analysis using the dispersion barrier hardening model, and defect property calculations via first-principles DFT. Competitive defect evolution under different fluences was summarized and compared with Ni-Mo-Cr. The results show that under low-to-medium (L-M) fluences, dislocation loops grow accompanied by a decrease in number, while He bubbles preferentially occupy nucleation sites to form dense high-pressure networks, thereby restricting the growth of dislocation loops. Under medium-to-high (M-H) fluences, He bubbles increase in size and decrease in number via the migration and coalescence, forming sparse low-pressure networks that enable dislocation loops to break through restrictions and grow further. This defect evolution difference caused severe hardening in the L-M stage but a negligible hardness increase in the M-H stage. Compared with the Ni-Mo-Cr alloy, the sizes of He bubbles and dislocation loops in the Ni-W-Cr alloy are reduced by 3.24 nm and 9.01 nm, respectively, and the hardness increment decreased by 0.40 GPa, which confirms the inhibitory effect of W substitution for Mo on irradiation damage at 850 °C. Density functional theory (DFT) reveals the advantages of W substitution at the atomic scale. DFT results indicate that the excellent properties of the Ni-26W-6Cr alloy originate from the easy formation of W vacancies capable of dissolving He, as well as the reduced damage to lattice stability caused by He substitution defects.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156122"},"PeriodicalIF":3.2,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Denise Adorno Lopes , Tash Ulrich , Andrew Kercher , Michael Bronikowski , Kyle Samperton , Spencer Scott , Matthew Wellons , Gage Green , Tyler Spano , Jason Harp , Andrew Nelson , Ashley E. Shields
{"title":"Corrigendum to “UO2 microstructural evolutions induced by Ni, Mo, and W dopants for intentional forensics” [Journal of Nuclear Materials, Volume 614 (2025) 155885]","authors":"Denise Adorno Lopes , Tash Ulrich , Andrew Kercher , Michael Bronikowski , Kyle Samperton , Spencer Scott , Matthew Wellons , Gage Green , Tyler Spano , Jason Harp , Andrew Nelson , Ashley E. Shields","doi":"10.1016/j.jnucmat.2025.156111","DOIUrl":"10.1016/j.jnucmat.2025.156111","url":null,"abstract":"","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156111"},"PeriodicalIF":3.2,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gongyuan Liu , Swapnil Morankar , Arvin Cunningham , William Chuirazzi , William Windes , Jing Du , Aman Haque
{"title":"Through-thickness fracture behavior of neutron-irradiated nuclear graphite NBG-17 Using X-ray micro-CT","authors":"Gongyuan Liu , Swapnil Morankar , Arvin Cunningham , William Chuirazzi , William Windes , Jing Du , Aman Haque","doi":"10.1016/j.jnucmat.2025.156119","DOIUrl":"10.1016/j.jnucmat.2025.156119","url":null,"abstract":"<div><div>Achieving precise control over crack propagation in nuclear graphite and conducting quantitative analysis remain challenging. In this study, the through-thickness fracture behavior of pristine and neutron-irradiated (700 °C, ∼7 dpa) NBG-17 nuclear graphite was investigated using split-disc testing coupled with micro-computed tomography (micro-CT). A notably lower number of micropores was observed in the neutron-irradiated specimen. The fracture toughness of neutron-irradiated NBG-17 was measured to be 1.45 MPa√m, compared to 1.17 ± 0.05 MPa√m for the pristine specimen. In both materials, cracks were found to initiate at the filler–binder interface, and often correlated with microstructural features such as pores and thermal cracks. Crack bridging and deflections emerged as the primary toughening mechanisms in both unirradiated and irradiated NBG-17. However, compared with the pristine specimen, the cracks in the neutron-irradiated specimen were more likely to grow trans granularly, resulting in less deflected crack paths. The reduced micro-porosity and strengthened filler–binder boundaries were considered to be the cause of the observed differences in crack morphologies. This study provides a qualitative analysis of the fracture behavior of neutron-irradiated nuclear graphite in the absence of radiolytic oxidation.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156119"},"PeriodicalIF":3.2,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liang Zhang , Shiyi Wen , Yuling Liu , Yong Du , Jiaqing Yin , Pei Zhang
{"title":"Thermodynamic modeling of the U-Nb-C and U-Ti-C systems over the entire composition and temperature ranges","authors":"Liang Zhang , Shiyi Wen , Yuling Liu , Yong Du , Jiaqing Yin , Pei Zhang","doi":"10.1016/j.jnucmat.2025.156121","DOIUrl":"10.1016/j.jnucmat.2025.156121","url":null,"abstract":"<div><div>Knowledge about the phase equilibria of the U-Nb-C and U-Ti-C systems is critical for designing U-based alloys and UC nuclear fuels. The ionic two-sublattice model offers the advantage of describing the liquid phase in a large range of composition: metal, ionic and liquid carbon with a single set of parameters. In order to reasonably extend the current thermodynamic descriptions to oxide systems, the ionic two-sublattice model is used in this work to describe the liquid phase. However, the thermodynamic parameters for the liquid phase in the Nb-C and Ti-C systems have not been previously described using the ionic two-sublattice model, and there is no reliable thermodynamic description for the U-Nb-C system. In this work, the Nb-C and Ti-C binary systems were re-optimized, and the U-Nb-C and U-Ti-C ternary systems were assessed using the CALPHAD (CALculation of PHAse Diagrams) approach, incorporating critically evaluated experimental phase equilibrium data. A set of self-consistent thermodynamic parameters was obtained to describe the phase equilibria in these systems. The calculated phase diagrams show excellent agreements with reliable experimental data. The developed thermodynamic descriptions provide a foundation for constructing multicomponent U-based thermodynamic databases and support the design of advanced nuclear materials, as well as impurity control in uranium alloys.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156121"},"PeriodicalIF":3.2,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}