Journal of Nuclear Materials最新文献

{"title":"Investigating the synergistic evolution of H and He with irradiation defects in Fe by a new Fe-H-He ternary potential","authors":"Hao-Xuan Huang ,&nbsp;Yu-Hao Li ,&nbsp;Tian-Ren Yang ,&nbsp;Hong-Bo Zhou ,&nbsp;Jin-Liang Li ,&nbsp;Hui-Zhi Ma ,&nbsp;Yu-Ze Niu ,&nbsp;Xiao-Chun Li ,&nbsp;Huiqiu Deng ,&nbsp;Guang-Hong Lu","doi":"10.1016/j.jnucmat.2025.155687","DOIUrl":"10.1016/j.jnucmat.2025.155687","url":null,"abstract":"<div><div>It has been demonstrated that the synergistic effect of hydrogen (H) and helium (He) has a significant promoting effect on the nucleation antungstend growth of irradiation defects, leading to severe deterioration of material performance. In order to explore the synergistic evolution behaviors of H and He with irradiation defects in iron (Fe), we have developed a new Fe-H-He ternary potential through systematic fitting and optimization. During the processes, the interaction between H and He with vacancies and interstitial defects is given prominent consideration. Based on the present potential, we further explored the cooperative evolution behaviors of H-He-void complexes. On the one hand, it is clearly observed that both H and He perfectly form a typical core-shell structure in nanovoids with He inside and H outside, which is consistent with experimental observation. The number of H atoms trapped by He-void complexes will decrease with the increasing of He/V ratios, which is due to the repulsion between H and He. On the other hand, the presence of He-void complexes has a significant promoting effect on the formation of H platelets in Fe. The stress field generated by He-void complexes facilitates the aggregation and initial formation of H platelets, and its range expands as H aggregates, ultimately resulting in the formation of H platelets. The high H concentrations are required to form H platelets at high temperature. More importantly, the formation of H platelets can induce a transition in the local Fe lattice from body-centered cubic to face-centered cubic, indicating a substantial impact on the microstructure and properties of Fe. Consequently, the new Fe-H-He potential provides a powerful tool for exploring the synergistic evolution of H-He-defects and evaluating the performance of Fe in fusion devices.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155687"},"PeriodicalIF":2.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377875","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":"Investigation on the SCC susceptibility of a heat-optimized l-PBF 304L stainless steel in simulated primary water","authors":"Kai Chen ,&nbsp;Yuhao Zhou ,&nbsp;Fawen Zhu ,&nbsp;Shixin Gao ,&nbsp;Quanyao Ren ,&nbsp;Kun Zhang ,&nbsp;Xiaoqing Shang ,&nbsp;Lefu Zhang","doi":"10.1016/j.jnucmat.2025.155685","DOIUrl":"10.1016/j.jnucmat.2025.155685","url":null,"abstract":"<div><div>This study examines the stress corrosion cracking (SCC) behavior of laser powder bed fusion (L-PBF) 304 L stainless steel after solution annealing (SA) in high-temperature water environments. SCC susceptibility was evaluated under both hydrogenated and oxygenated water environments at 325 °C and 15.5 MPa. The results showed that heat-treated l-PBF 304 L exhibited fully recrystallized equiaxed grains, characterized with high-density annealing twins and a uniform microstructure. Stress-strain tests revealed a marked reduction in elongation and mixed intergranular (IG) and transgranular (TG) cracking, indicating significant SCC susceptibility in both environments. Notably, hydrogenated water conditions led to a higher proportion of TG cracking, suggesting enhanced hydrogen embrittlement (HE), while oxygenated conditions favored IG cracking. Cross-sectional analysis highlighted localized strain concentration at crack tips, and precipitates were found to play a critical role in the initiation and propagation of cracks. These findings provide crucial insights into the relationship between microstructure, environmental factors, and SCC behavior in l-PBF 304 L stainless steel.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155685"},"PeriodicalIF":2.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377874","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":"Study of thermal diffusivity degradation on Cu-OFE copper due to proton and self-ion irradiation using in situ transient grating spectroscopy","authors":"Emmanouil Trachanas ,&nbsp;Angus Wylie ,&nbsp;Andrea Bignami ,&nbsp;Nikolaos Gazis ,&nbsp;Michael P. Short ,&nbsp;Katrin Michel ,&nbsp;Carl Alwmark ,&nbsp;Evangelos Gazis ,&nbsp;Georgios Fikioris ,&nbsp;Håkan Danared","doi":"10.1016/j.jnucmat.2025.155674","DOIUrl":"10.1016/j.jnucmat.2025.155674","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The operation of next-generation particle accelerator facilities with increased beam power parameters and emphasis on performance and reliability signifies the need for experimental studies on material property degradation. Literature is particularly scarce regarding the effects of ionizing radiation damage on cavity components at applicable radiation conditions, with even less extant work studying the effect of simultaneous irradiation on primary materials and their physical properties such as thermal transport. This study presents the impact on thermal diffusivity in oxygen-free electronic Cu-OFE specimens due to proton and self-ion (&lt;span&gt;&lt;math&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;) irradiation. Copper samples with the exactly same processing route as the bulk material for European Spallation Source (ESS) Radio-Frequency Quadrupole (RFQ) were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and electron backscatter diffraction (EBSD), followed by irradiation at room temperature with protons and self-ions (&lt;span&gt;&lt;math&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;) with fluences up to 4.25 × 10&lt;sup&gt;17&lt;/sup&gt; &lt;span&gt;&lt;math&gt;&lt;mtext&gt;p&lt;/mtext&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mtext&gt;cm&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mn&gt;1.10&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;15&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mtext&gt;ions&lt;/mtext&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mtext&gt;cm&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mn&gt;1.69&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;15&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mtext&gt;ions&lt;/mtext&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mtext&gt;cm&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; respectively. &lt;em&gt;In situ&lt;/em&gt; ion irradiation transient grating spectroscopy (I&lt;sup&gt;3&lt;/sup&gt;TGS) was used in order to monitor radiation-induced changes in thermal diffusivity in real time. The results indicate a significant thermal diffusivity drop only after the proton irradiation (10.86%) in contrast to the results obtained for self-ions (&lt;span&gt;&lt;math&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;) where no significant changes (&lt;span&gt;&lt;math&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/math&gt;&lt;/span&gt;) are reported. The results are compared with existing literature and correlated with the nature of post-irradiation defect structures based on the particle type. In the case of protons the contribution of hydrogen implantation in stabilization of defects and on the reduction of thermal diffusivity is discussed. &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;G&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; in combination with concurrent ion irradiation offers a powerful online diagnostic tool for the evaluation of the impact of operational parameters in particle accelerat","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155674"},"PeriodicalIF":2.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143237316","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":"Buffering the oxygen activity of uranium dioxide fuels using niobium and molybdenum as redox additives","authors":"Philippe Garcia ,&nbsp;Erwin Douguet-Bronnec ,&nbsp;Franck Fournet-Fayard ,&nbsp;Florian Le Hello ,&nbsp;Xavière Iltis ,&nbsp;Nicolas Tarisien ,&nbsp;Jacques Fouletier ,&nbsp;Marlu Cesar Steil","doi":"10.1016/j.jnucmat.2025.155647","DOIUrl":"10.1016/j.jnucmat.2025.155647","url":null,"abstract":"<div><div>We demonstrate that it is possible to control the oxygen activity of a uranium oxide fuel by incorporating additives during the manufacturing process that have a strong redox activity. To this end, we have studied the macroscopic electrochemical properties of three polycrystalline uranium dioxide samples, the first containing both molybdenum and molybdenum dioxide, the second containing niobium dioxide and the last containing no additives other than impurities. During experiments, samples were subjected to reducing and subsequently oxidizing atmospheres with respect to the oxygen partial pressure at which the oxidized and reduced forms of the additives are in equilibrium. <em>In situ</em> monitoring of the electrochemical response of the samples reveals that the presence of redox couples involving either niobium or molybdenum significantly modifies the oxygen activity of a uranium dioxide solid. Scanning Electron Microscopy (SEM), Electron Back-Scatter Diffraction (EBSD) and Energy Dispersive X-ray analysis (EDX) prior to and following the high temperature measurements, confirm the <em>in situ</em> data: the final microstructure purports to show that the electrochemical activity is controlled by the Mo/MoO₂ and the NbO₂/Nb₂O₅ couples for the molybdenum and niobium containing samples respectively.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155647"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428248","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":"Characterization of plasma in the HiPIMS facility for simulation of fusion-oriented W co-deposition in He/H2 and He/D2 environments","authors":"Maksim M. Kharkov ,&nbsp;Gleb S. Lomonosov ,&nbsp;Mikhail S. Novikov ,&nbsp;Dobrynya V. Kolodko ,&nbsp;Alexander V. Tumarkin ,&nbsp;Vitaly S. Efimov ,&nbsp;Olga V. Ogorodnikova ,&nbsp;Andrey V. Kaziev","doi":"10.1016/j.jnucmat.2025.155675","DOIUrl":"10.1016/j.jnucmat.2025.155675","url":null,"abstract":"<div><div>A new facility based on a HiPIMS (high-power impulse magnetron sputtering) discharge plasma with a hot tungsten (W) target for the investigation of co-deposition of W with helium (He) and hydrogen (H₂, D₂) isotopes on W substrate was developed. To find the ion fluxes from He/H₂ and He/D₂ plasma together with W ions from W target incident on installed samples, the ion mass spectrometric study of a HiPIMS plasma was performed. The results reveal a mixed composition of ion fluxes consisting mainly of monoatomic H⁺(D⁺) and He⁺, diatomic H₂⁺(D₂⁺) and HeH⁺, and triatomic H₃⁺ ions. The content of tungsten ions does not exceed 2 % in any of the explored discharge regimes. The contributions of different species to the total flux are strongly affected by the discharge pulsing parameters, especially pulsed power density. For pulsed power densities below 200 W/cm², H₃⁺ ions in the He/H₂ or D₃⁺ in He/D₂ gas mixtures dominate in the ion flux. The opposite situation of monoatomic ion fraction (H⁺ and D⁺) prevailing over molecular ions is observed in the case of the pulse power density above the values: 400 W/cm² for prevailing of H⁺ in He/H₂ gas mixture discharge, and 900 W/cm² for prevailing of D⁺ in He/D₂ gas mixture discharge. The most suitable discharge modes are selected for future simulation of W co-deposition processes with He/H₂ and He/D₂ gas mixtures. Preliminary data on the thickness of co-deposits in various regimes have been obtained. The He retention in W irradiated at the HiPIMS facility in hydrogen plasma with ∼ 10 % He ion seeding was validated by comparison with the experimental data after irradiation of W under the same conditions in a linear plasma device.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155675"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143237315","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":"Effect of irradiation parameters on defect evolution in neutron irradiated tungsten","authors":"M. Klimenkov ,&nbsp;U. Jäntsch ,&nbsp;M. Rieth ,&nbsp;H.C. Schneider ,&nbsp;D. Terentyev ,&nbsp;W. Van Renterghem","doi":"10.1016/j.jnucmat.2025.155673","DOIUrl":"10.1016/j.jnucmat.2025.155673","url":null,"abstract":"<div><div>The article presents a microstructural examination of neutron-irradiated tungsten (W), that was irradiated to four damage doses of 0.1 dpa, 0.2 dpa, 0.5 dpa and 0.8 dpa and at four temperatures of 600°C, 800°C, 900°C and 1200°C in the BR2 material test reactor (Mol, Belgium). The irradiation parameters cover a wide range that enables a comprehensive study of defect formation and evolution. The experimental work includes imaging and quantitative analysis of radiation induced voids and dislocation loops as well as the visualization of the distribution of the transmutation induced Re and Os. It demonstrates the dose- and temperature-dependent evolution of defect's size and number density as well as the segregation behavior of Re and Os at these defects. It was proven that the size of the defects increases, while their number density decreases with increasing damage dose. The formation of nanometer-sized Re–Os precipitates with elongated shape was detected in samples irradiated at 0.8 dpa. The large-scale EDX analysis showed the influence of grain and sub-grain boundaries as well as line dislocations on defect formation and thus on Re and Os-segregation behavior.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155673"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmission Electron Microscopy Characterization of Fuel Cladding Chemical Interaction between Minor Actinides bearing U-Pu-Zr Fuel and AIM1 Cladding","authors":"Di Chen,&nbsp;Jatuporn Burns,&nbsp;Karen E. Wright,&nbsp;Daniele Salvato,&nbsp;Tiankai Yao,&nbsp;Luca Capriotti","doi":"10.1016/j.jnucmat.2025.155667","DOIUrl":"10.1016/j.jnucmat.2025.155667","url":null,"abstract":"<div><div>Minor actinides (MA) significantly contribute to the long-term radiotoxicity of spent nuclear fuel (SNF). Separating MA from SNF and incorporating it into metallic fuels for fast reactor transmutation is a potential method to reduce this radiotoxicity. This study focuses on transmission electron microscopy characterization of two samples from the fuel cladding chemical interaction (FCCI) region of an americium (Am) and neptunium (Np)-bearing (MA-bearing) uranium-plutonium-zirconium (U-Pu-Zr) fuel irradiated in the Phenix fast reactor to 9.5 % FIMA burnup at approximately 550 °C cladding temperature. The results show that despite the complex chemical interactions between MA and AIM1 cladding elements, excessive FCCI was not induced, and Am penetration depth in the cladding limited to less than 4 μm. Np remained mostly inside fuel. The Zr-rich compounds layer effectively limited the accumulation of lanthanide on the inner cladding surface. Overall, the FCCI behavior between investigated MA-bearing U-Pu-Zr fuel and AIM1 cladding is benign.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155667"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454719","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":"A vacancy dynamic evolution model based on rate theory and its influence on hydrogen isotope retention behavior","authors":"Fei Sun ,&nbsp;Xiangming Lin ,&nbsp;Yijin Huang ,&nbsp;Jipeng Zhu ,&nbsp;Long Cheng ,&nbsp;Yifan Zhang ,&nbsp;Hai-Shan Zhou ,&nbsp;Lai-Ma Luo ,&nbsp;Yasuhisa Oya ,&nbsp;Yucheng Wu","doi":"10.1016/j.jnucmat.2025.155676","DOIUrl":"10.1016/j.jnucmat.2025.155676","url":null,"abstract":"<div><div>In fusion environments, plasma-facing materials are subjected to the bombardment by high-energy neutrons and large fluxes plasmas, resulting in the formation of numerous irradiation defects. These defects act as trapping sites for fuel hydrogen isotopes, increasing the tritium retention. Under thermal loads at high temperatures, these defects undergo dynamic changes, leading to complex effects on hydrogen isotope transport behaviors. Understanding the evolution of defects at different temperatures and elucidating their impact on hydrogen isotope retention is essential. In this work, a dynamic evolution model of typical vacancy defects and their clusters was constructed based on rate theory and integrated into the hydrogen isotope transport model. The simulation results were compared with experimental data, showing a good agreement between the two. Further results indicated that increasing the annealing temperature reduces defect concentrations. At high temperatures, large vacancy clusters dissociate into smaller ones, with some smaller clusters annihilating and others associating to form larger clusters. In addition, the processes of vacancy clusters association and dissociation dominate this evolution. Regarding hydrogen isotope retention, defect evolution affects the concentration of deuterium (D) atoms within the material. After D is introduced into tungsten, the concentration of D corresponds to the concentration of vacancy clusters. It is found that during thermal desorption, the desorption peak corresponding to the largest vacancy clusters is more pronounced, while other clusters show less significant peaks. This is because some of the D atoms de-trapped from the vacancy clusters are released to the material surface, while others are re-trapped by larger vacancy clusters. The findings of this work will contribute to a more accurate assessment of hydrogen isotope retention under defect dynamic evolution in future fusion reactors.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155676"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143360821","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":"Atomic-scale mechanisms of He-induced dislocation loop growth in α-Fe from molecular dynamics simulations","authors":"Ziqiang Wang,&nbsp;Xiangyan Li,&nbsp;Yange Zhang,&nbsp;Yichun Xu,&nbsp;Changsong Liu,&nbsp;Xuebang Wu","doi":"10.1016/j.jnucmat.2025.155672","DOIUrl":"10.1016/j.jnucmat.2025.155672","url":null,"abstract":"<div><div>The interaction between helium (He) and irradiation damage is crucial for understanding the degradation mechanisms and performance of structural materials for fusion applications. However, the atomic-scale mechanisms underlying the helium influence on dislocation loop growth remain poorly understood. In this work, we investigated the interactions between He and interstitial dislocation loops in bcc iron using molecular dynamics simulations. It was found that the formation of He bubbles around dislocation loops enhances loop growth through the dislocation climb mechanism. An increased He implantation rate results in a higher growth rate of dislocation loops, with more He bubble nucleation on the loops leading to greater loop extension. Furthermore, the interactions between dislocation loops and immobile He bubbles contribute to loop enlargement through the dislocation loop absorption mechanism. Larger He bubbles induce a more substantial rise in loop length. These findings provide valuable insights into the atomic-scale processes by which He promotes dislocation loop growth in α-Fe, advancing our understanding of He-induced irradiation damage in fusion materials.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155672"},"PeriodicalIF":2.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143237314","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":"Assessment of structural stability and leaching characteristics of phosphate-based geopolymer waste form containing radioactive spent ion exchange resins","authors":"Byoungkwan Kim ,&nbsp;Younglim Shin ,&nbsp;Solmoi Park ,&nbsp;Brant Walkley ,&nbsp;Seokyoung Oh ,&nbsp;Jaehyuk Kang ,&nbsp;Wooyong Um","doi":"10.1016/j.jnucmat.2025.155671","DOIUrl":"10.1016/j.jnucmat.2025.155671","url":null,"abstract":"<div><div>The use of hydrated waste forms, such as cement, for immobilizing radioactive spent ion-exchange resins (IERs) is unsuitable due to low waste loading, high leaching of radionuclides, and poor durability. Here, simulant spent IERs were immobilized by a phosphate-based geopolymer (P-GP) for the first time. The 7-day compressive strength of the P-GP waste form was inversely proportional to waste loading because the pore size of the P-GP waste form increased with increasing waste loading. The P-GP waste forms with 40 wt% spent IERs satisfied all of South Korea's waste acceptance criteria for compressive strength, thermal cycling, water immersion, and gamma irradiation tests. The leaching behaviors of Co, Cs, and Sr differed from those of alkali-activated materials, but the leaching index exceeded the criterion value of 6.0. The leaching mechanism was governed by the combination of surface wash-off and diffusion or solely diffusion. The P-GP waste form could play as a primary physical barrier against releasing radionuclides. In addition, the geopolymer waste form did not undergo significant structural changes after waste acceptance criteria tests, indicating that it can efficiently immobilize spent IERs. Our findings can contribute new insights into efficient waste form materials for immobilizing radioactive spent IERs.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"607 ","pages":"Article 155671"},"PeriodicalIF":2.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143237313","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}