Journal of Nuclear Materials最新文献

{"title":"Metallic fuel transient fuel-cladding interface liquefaction model assessment platform enabled by integrating BISON with databases","authors":"Yinbin Miao ,&nbsp;Shipeng Shu ,&nbsp;Aaron Oaks ,&nbsp;Carolyn Tomchik ,&nbsp;Kun Mo ,&nbsp;Christopher Matthews ,&nbsp;Adam Zabriskie ,&nbsp;Stephen Novascone ,&nbsp;Abdellatif M. Yacout","doi":"10.1016/j.jnucmat.2025.156168","DOIUrl":"10.1016/j.jnucmat.2025.156168","url":null,"abstract":"<div><div>A novel platform has been developed within the BISON fuel performance code to assess models of fuel-cladding interface liquefaction for sodium-cooled fast reactor (SFR) metallic fuels. This platform is crucial because liquefaction at the fuel-cladding interface significantly impacts fuel performance and may compromise fuel pin integrity during transient events. To ensure accurate predictions, the platform integrates data collected during the Integral Fast Reactor (IFR) program, now archived in metallic fuel databases. This integration supports verification and validation (V&amp;V) of the models in BISON. Leveraging the extensive US experience with metallic fuel liquefaction and the collections of preserved legacy data, the platform serves as a powerful tool for evaluating existing models and advancing the development of new ones.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"618 ","pages":"Article 156168"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120675","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":"The evolution of NiMnSi clusters in RPV steels under proton irradiation: The effect of Cu","authors":"Wenqiang Wang ,&nbsp;Bin Li ,&nbsp;Miao Fu ,&nbsp;Wenqing Jia ,&nbsp;Qiwei Quan ,&nbsp;Xiangbing Liu ,&nbsp;Wenqing Liu","doi":"10.1016/j.jnucmat.2025.156174","DOIUrl":"10.1016/j.jnucmat.2025.156174","url":null,"abstract":"<div><div>Cu is an impurity element in nuclear reactor pressure vessel (RPV) steel, and even trace amounts can induce irradiation hardening and embrittlement. Proton irradiation experiments with a range of fluences were carried out on Chinese RPV steel (0.027 wt.% Cu) and the simulated steel with a high Cu fraction (referred to as RCA, 0.62 wt.% Cu) in this study. The samples' hardness was assessed by means of nano-indentation both before irradiation and after irradiation, and the evolution of NiMnSi clusters in the two types of irradiated steels was analyzed via atom probe tomography (APT) technology. Research results indicate that Cu element can promote the nucleation of NiMnSi clusters, which leads to a greater volume fraction of NiMnSi clusters in irradiated RCA steels compared to RPV steels, resulting in a more significant irradiation hardening effect in RCA steels. At the same time, Cu appears to suppress the growth of NiMnSi clusters. As irradiation damage accumulates, the composition of NiMnSi clusters in RPV steels approached that of the G phase (Ni₁₆Mn₆Si₇), while in RCA steels, a gradual separation trend of NiMnSi clusters and Cu clusters was observed, and the composition of NiMnSi clusters changed to be closer to the τ₂ phase (Ni₃Mn₂Si).</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"618 ","pages":"Article 156174"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156792","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":"3D pore structure reconstruction of fluff region in top of EBR-II irradiated fuel by X-ray micro-computed tomography","authors":"Jake Fay ,&nbsp;William Chuirazzi ,&nbsp;Luca Capriotti ,&nbsp;Fidelma Di Lemma ,&nbsp;Cameron Howard ,&nbsp;Mario Matos ,&nbsp;Jie Lian","doi":"10.1016/j.jnucmat.2025.156167","DOIUrl":"10.1016/j.jnucmat.2025.156167","url":null,"abstract":"<div><div>Metallic fuels comprised of U-Zr binary and U-Pu-Zr ternary alloys are a promising fuel candidate for sodium-cooled fast reactors and possess many advantages over ceramic fuels such as higher uranium density and improved thermal conductivity. Fluff is a highly porous structure forming at the top of metallic fuel slugs during irradiation and was extensively observed in past sodium-cooled fast reactor (SFR) experiments such as Idaho National Laboratory’s Experimental Breeder Reactor II (EBR-II). Previous investigations have shown that fluff is rich in fissile atoms and hence could have neutronics implications, but its formation mechanisms are not understood. In this work, two cube-shaped lift outs were taken from the fluff and bulk fuel regions of a high burnup U-19Pu-10Zr composition EBR-II fuel slug and characterized by micro computed tomography (Micro-CT) and energy dispersive x-ray spectroscopy (EDS). This was used to characterize differences in microscale porosity and composition between fluff and bulk fuel, and to support or oppose postulated fluff formation mechanisms. Surface EDS showed minimal differences between the elemental compositions of the fluff and fuel cubes. However, three-dimensional (3D) pore analysis from the tomography scans showed significant differences between the fluff and fuel cube pore size distributions at the microscale level. The high porosity and irregular pore distribution seen in macroscale fluff was also present within the micro-scale fluff cube, having a much higher porosity than the fuel cube which was concentrated in a few large pore networks. These results indicate support for a creep driven mechanism of fluff formation.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"618 ","pages":"Article 156167"},"PeriodicalIF":3.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156793","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":"Unraveling Be behavior near the Mo(110) surface: A DFT study of Adsorption, diffusion, and aggregation mechanisms","authors":"Haijun Li ,&nbsp;Aoyu Mo ,&nbsp;Wenjie Li ,&nbsp;Xiaowei Ma ,&nbsp;Yunshan Xiong ,&nbsp;Peng Shao ,&nbsp;Bo Li ,&nbsp;Kun Jie Yang ,&nbsp;Yue-Lin Liu ,&nbsp;Quan-Fu Han","doi":"10.1016/j.jnucmat.2025.156170","DOIUrl":"10.1016/j.jnucmat.2025.156170","url":null,"abstract":"<div><div>Understanding beryllium (Be) impurity deposition on molybdenum (Mo) surfaces is crucial for advancing Mo's use as first mirrors in tokamak fusion devices. Using first-principles density functional theory (DFT), We systematically investigate the adsorption, diffusion, and aggregation behaviors of Be atoms near the Mo(110) surface. Be atoms preferentially adsorb at Hollow sites on Mo(110) surfaces, with adsorption energies decreasing as Be coverage increases. This trend is driven by enhanced Be–Be binding, which dominates at higher coverages. Be aggregation leads to stable quadrilateral Be clusters, reflecting strong structural orientation. Diffusion studies reveal a preferred Hollow→Bridge→Hollow pathway with a 0.57 eV barrier, while surface-to-subsurface penetration requires overcoming a significantly higher energy barrier of 3.69 eV. Be atoms in the subsurface region preferentially occupy octahedral interstitial sites between atomic layers (OIS2), which results in a higher Be concentration between the Mo atomic layers. The positive binding energy between Be atoms facilitates interlayer nucleation. Subsequently, Beₙ clusters can readily displace Mo atoms, resulting in the formation of vacancy–interstitial pairs. This process may lead to the formation of Be-rich precipitates in this region, potentially causing cracking or exfoliation of the Mo surface atomic layers.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"618 ","pages":"Article 156170"},"PeriodicalIF":3.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156803","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":"Immobilisation of simulant nuclear-grade spent ion-exchange resins in alkali-activated cement: Fresh state properties of the cement matrix","authors":"M. Jimena de Hita ,&nbsp;Elena Torres ,&nbsp;Daniel A. Geddes ,&nbsp;John L. Provis ,&nbsp;María Criado","doi":"10.1016/j.jnucmat.2025.156169","DOIUrl":"10.1016/j.jnucmat.2025.156169","url":null,"abstract":"<div><div>This study evaluates the fresh-state properties of alkali-activated cements (AACs) for the solidification of nuclear-grade spent ion-exchange resins (SIERs), a challenging waste stream in the nuclear industry. The formulations assessed use blast furnace slag and fly ash as precursors and Na₂SiO₃ and Na₂CO₃ as alkaline activators, for the immobilisation of SIERs. Setting time, workability, rheology, and reaction kinetics are assessed to optimise the cementitious matrix for effective waste encapsulation.</div><div>The incorporation of higher ash content slows reaction kinetics of the cement, delays setting, and reduces viscosity and yield stress, while slag accelerates polymerisation, increasing viscosity. Na₂CO₃ activation promotes early calcium carbonate precipitation, leading to faster setting and higher viscosity, whereas Na₂SiO₃ maintains fluidity over time. Resin incorporation is the dominant factor affecting fresh-state properties, significantly delaying reaction kinetics and reducing viscosity and yield stress, attributed to chemical interactions between Ca²⁺ from the pore solution and boron compounds released from the resin. Maintaining a setting time below 24 h, AACs with &gt;85% slag allow more resin content than Portland cement. Slower kinetics may improve the stability of the resin encapsulation by allowing it to adapt to deformations.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156169"},"PeriodicalIF":3.2,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118266","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 the impact of Zr-Cr eutectic reaction on the structural integrity of Cr-coated ATF cladding","authors":"Boyeon Kweon ,&nbsp;Hyunwoo Yook ,&nbsp;Dongju Kim ,&nbsp;Youho Lee","doi":"10.1016/j.jnucmat.2025.156166","DOIUrl":"10.1016/j.jnucmat.2025.156166","url":null,"abstract":"<div><div>The potential impact of the Zr-Cr eutectic reaction on the structural integrity of Cr-coated ATF cladding under prolonged high-temperature steam exposure was comprehensively and systematically assessed. Cr-coated Zr-Nb alloys with various coating thicknesses (5, 8, 10, 12, 16, 18 µm) were subjected to steam oxidation at temperatures above the Zr-Cr eutectic onset for up to 2 h. No evidence of melting flow or structural collapse attributable to the eutectic mixture (β-Zr+ZrCr₂) was observed, even after extended exposure under steam-oxidizing conditions. As the oxygen concentration in the Zr matrix increased, the corresponding rise in eutectic onset temperature led to solidification of the eutectic mixture, which remained as ZrCr₂ within the matrix. Furthermore, even in an oxygen-free inert environment, the amount of Cr—within the tested coating thickness range—was insufficient to drive eutectic mixture through the entire cladding thickness (570 µm). To assess safety margins related to potential structural failure, a straightforward yet accurate model was developed to predict the Cr-limited eutectic thickness as a function of initial coating thickness, and was experimentally validated. According to the model, a Cr coating thickness of ∼72 µm would be required to form the eutectic mixture across the entire cladding wall. Even when accounting for the partially thickened eutectic reaction region (‘Thick zone’), the coating would need to exceed ∼49 µm reach full thickness. These findings suggest that, at coating thicknesses currently considered for commercial application (∼15–20 µm), safety concerns at the eutectic onset temperature should focus on oxidation-induced embrittlement rather than eutectic melting-induced collapse.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156166"},"PeriodicalIF":3.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154832","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":"Thermal and diffusional properties of uranium-americium and plutonium-americium mixed oxides","authors":"A. Chakraborty ,&nbsp;P.S. Ghosh ,&nbsp;N. Choudhury ,&nbsp;A. Arya","doi":"10.1016/j.jnucmat.2025.156152","DOIUrl":"10.1016/j.jnucmat.2025.156152","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The knowledge of thermo-physical and transport properties of mixed oxide fuels containing minor actinides such as Americium (Am) and Neptunium (Np) is of paramount importance in the front end of the nuclear fuel cycle. Because of the radiotoxic nature of these materials, a priory evaluation of these properties using theoretical and computational means is immensely useful. In the present work, various thermal and diffusional properties, like, thermal expansion, specific heats, thermal conductivity, and oxygen vacancy migration barriers of U&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; and Pu&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; mixed oxides (MOX) are determined by extensive molecular dynamics (MD) simulations. Unlike most of the previous MD simulation studies, the present work explicitly considers the effect of different oxidation states, such as U&lt;sup&gt;+4&lt;/sup&gt;, U&lt;sup&gt;+5&lt;/sup&gt; and Am&lt;sup&gt;+3&lt;/sup&gt;, by using a new interatomic potential to evaluate the thermal properties of U&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; MOX. For linear thermal expansion, the results obtained by using new interatomic potential in U&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; with 0 ≤ y ≤ 0.3125 and Pu&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; are in excellent agreement with those obtained from the experimental studies. The peaks in the thermal expansion coefficient (&lt;em&gt;α&lt;/em&gt;) and specific heat (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) versus temperature plots originated due to the Bredig transition in U&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; MOX shifts towards lower temperature as y increases up to 0.3125. This is qualitatively consistent with an almost linear decrease of the melting points with the increase in y as observed in experiments. The MD calculated &lt;em&gt;α&lt;/em&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; values of U&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Am&lt;sub&gt;&lt;em&gt;y&lt;/em&gt;&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; MOX (for &lt;span&gt;&lt;math&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mn&gt;0.3125&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;) are fitted to the Bathellier equation which can be used to determine high temperature behavior of the MOX fuel where no experimental data is available. The impact on the thermal conductivity (TC) for the introduction of AmO&lt;sub&gt;2&lt;/sub&gt; into UO&lt;sub&gt;2&lt;/sub&gt; is much stronger than that of the introduct","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156152"},"PeriodicalIF":3.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109525","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":"Evidence of a phase transition from UO2-x to UO2+x","authors":"L. Desgranges ,&nbsp;A. Canizares","doi":"10.1016/j.jnucmat.2025.156161","DOIUrl":"10.1016/j.jnucmat.2025.156161","url":null,"abstract":"<div><div>Uranium dioxide has been extensively studied for &gt;70 years with regards to its importance as main nuclear fuel used worldwide. From a thermodynamic point of view, UO₂ was considered up to now as a single phase, in which point defects would explain its sharp change of oxygen potential when going from hypo to hyper-stoichiometry. Here, we demonstrate using Raman spectroscopy, that the change from hypo to hyper-stoichiometry should be considered as a phase transition. This leads us to a change of paradigm about UO₂ that is now a border between UO_2-x and UO₂₊<em>_x</em>.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156161"},"PeriodicalIF":3.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105194","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 temperature on dislocation loop evolution in RPV model steel: In-situ Fe+ irradiation","authors":"Hucheng Yu ,&nbsp;Yuanyuan Dong ,&nbsp;Ziqi Cao ,&nbsp;Yifan Ding ,&nbsp;Xiaotong Wang ,&nbsp;Jiyong Huang ,&nbsp;Guang Ran","doi":"10.1016/j.jnucmat.2025.156164","DOIUrl":"10.1016/j.jnucmat.2025.156164","url":null,"abstract":"<div><div>To better understand the evolution of dislocation loops in RPV steel at different temperatures, in-situ irradiation experiments of 400 keV Fe⁺were conducted using a RPV model alloy Fe–1.0Mn–0.7Ni–0.2Si (wt.%) at 240 °C, 350 °C, 450 °C, and 550 °C. The nucleation rate of dislocation loops increases first and then decreases with the increase of irradiation dose when <em>T</em> &lt; 550 °C. The lower the temperature, the higher the nucleation rate of dislocation loop. The relationships between the average size &amp; number density of dislocation loops and damage dose, as well as irradiation temperatures, is analyzed. The data indicate that higher irradiation temperatures result in larger loops with lower density. This is most evident at 550 °C, where both the average size and number density of dislocation loops vary significantly. Furthermore, quantitative analysis of the proportion of ½&lt;111&gt; and 〈100〉 dislocation loops at different temperatures reveals that when the temperature increases from 450 °C to 550 °C, the proportion of 〈100〉 loops decreases, for example, from 42 % to 25 % at 3.0 dpa. Moreover, the irradiation hardening induced by dislocation loops generally decreases with increasing temperature. These findings offer novel insights into the irradiation damage mechanisms in RPV steel.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156164"},"PeriodicalIF":3.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105195","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 noncollinear density functional theory ansatz for the phononic and thermodynamic properties of α-Pu","authors":"Alexander R. Muñoz ,&nbsp;W. Adam Phelan ,&nbsp;Matthew S. Cook ,&nbsp;Greta L. Chappell ,&nbsp;Paul H. Tobash ,&nbsp;David C. Arellano ,&nbsp;Derek V. Prada ,&nbsp;Travis E. Jones ,&nbsp;Sven P. Rudin","doi":"10.1016/j.jnucmat.2025.156151","DOIUrl":"10.1016/j.jnucmat.2025.156151","url":null,"abstract":"<div><div>Plutonium's phase diagram is host to complex structures and interactions that make the description of its ground state properties elusive. Using all-electron density functional theory calculations, we study the thermodynamic properties of <em>α</em>-Pu. To do this, we build on recent work in the literature by introducing a novel noncollinear magnetic ansatz for <em>α</em>-Pu's ground state. We show that the noncollinear ansatz improves the description of the experimental phonon density of states, heat capacity, and thermal expansion over previous results obtained with a collinear ansatz. Despite lacking a bond-equivalent picture of the bonding, these new results for <em>α</em>-Pu, along with recent results on <em>δ</em>-Pu, demonstrate the efficacy of noncollinear ansatzes for the description of plutonium.</div></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":"617 ","pages":"Article 156151"},"PeriodicalIF":3.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118265","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}