Nuclear Engineering and Technology最新文献

{"title":"Correlation between boron content and thermal neutron attenuation coefficient in borated stainless steels analyzed by neutron diffraction","authors":"Wanchuck Woo ,&nbsp;Hobyung Chae ,&nbsp;Myung-Kook Moon ,&nbsp;In-Hwan Oh ,&nbsp;Eunjoo Shin ,&nbsp;Taejoo Kim ,&nbsp;Jongyul Kim ,&nbsp;Jae Hoon Jang ,&nbsp;Sang Woo Song ,&nbsp;Tae-Ho Lee","doi":"10.1016/j.net.2025.103904","DOIUrl":"10.1016/j.net.2025.103904","url":null,"abstract":"<div><div>The relationship between boron content and thermal neutron attenuation coefficient was examined in fifteen kinds of borated stainless steels alloyed with the weight percentage of 0.19–1.87 boron. The attenuation coefficients were measured by the ratio of the neutron intensity transmitted by the borated stainless steel to the initial intensity without transmission. The neutron intensity was analyzed by the diffraction peak with the wavelengths of 0.131, 0.146, and 0.1836 nm. The result shows that the attenuation coefficient of 1.491 cm⁻¹ increases up to 5.412 cm⁻¹, which means a significant decrease of the peak intensity, as the boron content increases from 0.19 wt% to 1.87 wt% in the borated stainless steels. It is attributed to the high areal density (g/cm²) of ¹⁰B isotope in the natural boron, which has a large neutron microscopic cross-section. The measured attenuation coefficients are comparable to the theoretically calculated ones based on the microscopic cross-sections of contained elements in each alloy. Besides, it is proportional to the neutron wavelength due to the decrease of the neutron energy. This paper provides the correlation among the boron content, specimen thickness, and transmission ratio of thermal neutrons at wavelengths in the borated stainless steels.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103904"},"PeriodicalIF":2.6,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of the modified point kinetics model in the MARS code for molten salt reactors","authors":"Jae Jun Jeong ,&nbsp;Hong Sik Lim ,&nbsp;Kwi Seok Ha ,&nbsp;Yoon Jae Cho","doi":"10.1016/j.net.2025.103898","DOIUrl":"10.1016/j.net.2025.103898","url":null,"abstract":"<div><div>This study presents the implementation and verification of a modified point kinetics model (PKM) within the thermal-hydraulic system code MARS for application to liquid-fueled molten salt reactors (MSRs). Traditional PKMs for MSRs establish the delayed neutron precursor (DNP) balance equation by simplifying the reactor system into two regions: a reactor core and an external loop only. This approach is inadequate for realistic MSR systems with complex flow paths. To overcome this limitation, a three-dimensional DNP transport equation was introduced into the PKM instead of DNP balance equation, enabling a more accurate treatment of precursor distribution throughout the reactor system. The model was numerically solved in the MARS code using the upwind scheme, and the effective delayed neutron fraction was evaluated from steady-state precursor distributions. Verification of the modified PKM in the MARS code was performed through comparison with exact analytical solutions and the independently developed GAMMA + code. The results confirm the correctness and numerical accuracy of the modified PKM and demonstrate the MARS code's capability for both steady-state and transient analysis of liquid-fueled MSRs.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103898"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced Monte Carlo analysis of ex-vessel neutron dosimetry for cycle 25 of Krško nuclear power plant","authors":"Tanja Goričanec ,&nbsp;Benjamin Barbarič ,&nbsp;Vladimir Radulović ,&nbsp;Dušan Čalič ,&nbsp;Luka Snoj ,&nbsp;Marjan Kromar","doi":"10.1016/j.net.2025.103887","DOIUrl":"10.1016/j.net.2025.103887","url":null,"abstract":"<div><div>This paper presents the results of Monte Carlo neutron transport calculations performed for the containment building of the Krško Nuclear Power Plant. The calculations were performed using the Monte Carlo N-Particle Transport Code (MCNP) in combination with the ADVANTG hybrid code to speed up the convergence of the results outside the reactor core. The paper focuses on the analysis of the Ex-Vessel Neutron Dosimetry (EVND) program conducted during the 25^<em>th</em> fuel cycle at the Krško nuclear power plant with the irradiation of gradient chains and multiple foil sensor sets. The calculated reaction rates at the dosimeter locations are in good agreement with the measured values. However, deviations were observed in the thermal part of the neutron energy spectrum which cannot be neglected, and investigated were some possible reasons for the deviations: nuclear data, concrete material composition, concrete geometry, sensor position and impurities in sample.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103887"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-based visual prediction of hydrogen distribution in a passive autocatalytic recombiner","authors":"Won Jun Kim ,&nbsp;Jaehoon Jung ,&nbsp;Cong Truong Dinh ,&nbsp;Sung Goon Park","doi":"10.1016/j.net.2025.103897","DOIUrl":"10.1016/j.net.2025.103897","url":null,"abstract":"<div><div>Maintaining the operational stability of Nuclear Power Plants (NPPs) during severe accident environments requires a comprehensive understanding of local hydrogen distribution. To mitigate hydrogen-associated risks, Passive Autocatalytic Recombiners (PARs), which operate passively through catalytic reactions, are extensively installed within the containment structures. This study numerically investigates the thermohydraulic behavior of PARs under various accidental conditions, specifically focusing on the effects of inlet velocity and temperature. Building upon previous research (Kim et al. [14]), this work aims to predict hydrogen distribution within PARs using only temperature and velocity data, applying Convolutional Neural Networks (CNN) with a U-Net and Auto-Encoder (AE) models featuring different encoder-decoder architectures (MLP-CNN, MLP-ResNet). The U-Net model shows outstanding predictive performance, achieving a MAPE of 2.32 %, MAE of 0.042, RMSE of 0.080, and Structural Similarity Index Measure (SSIM) of 0.99, using temperature and velocity contours as input data. AE models, which utilize low-dimensional thermohydraulic inputs such as inlet velocity, inlet temperature, and outlet temperature, also exhibit strong predictive capability. The MLP-CNN and MLP-ResNet architecture exhibit reliable performance, with MAPE below 2.8 %, MAE below 0.52, RMSE below 0.09, and SSIM above 0.92. This research highlights the feasibility of effectively visualizing hydrogen distribution in PARs through advanced data-driven models.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103897"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing and evaluating multiple kernel density estimators for local-scale atmospheric dispersion modeling at a representative AP1000 nuclear power plant site in China","authors":"Li Yang ,&nbsp;Sheng Fang ,&nbsp;Zhaoyang Wang ,&nbsp;Jiayue Song ,&nbsp;Xinpeng Li ,&nbsp;Yixue Chen","doi":"10.1016/j.net.2025.103880","DOIUrl":"10.1016/j.net.2025.103880","url":null,"abstract":"<div><div>This study proposes a particle-age-based bandwidth calculation method for the Uniform kernel, an efficient kernel density estimator (KDE) in Lagrangian Particle Dispersion Model (LPDM), to mitigate excessive smoothing of concentrations near release points. The proposed method, along with Parabolic and Gaussian kernels, was jointly validated against wind tunnel experiments of a representative AP1000 nuclear power plant site with complex topography and irregular building layouts. Sensitivity analyses were also performed to quantify the performance of three KDEs with different LPDM parameters. Results show that proposed method improves Uniform kernel's accuracy and meets acceptable criteria, achieving similar performances as the other two KDEs. Sensitivity analyses illustrate that three KDEs can suppress increasing stochastic errors with high-resolution grid settings. Uniform kernel's bandwidths near release point should vary sharply horizontally and smoothly vertically, with appropriate bandwidth multiplication factors from 0.3 to 0.5. Parabolic and Gaussian kernels show less sensitivity to maximum horizontal bandwidth. The integer governing the Gaussian kernel's cut-off mechanism should be at least 2. Uniform and Parabolic kernels may lead to partial loss of particle mass contribution with coarser grid sizes. Gaussian kernel demonstrates more robust performance with lower numbers of released particles.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103880"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism analysis of flow reversal phenomena in research reactor cores","authors":"Yuan Huang,&nbsp;Meng Lv,&nbsp;Heng Xie,&nbsp;Lei Shi","doi":"10.1016/j.net.2025.103861","DOIUrl":"10.1016/j.net.2025.103861","url":null,"abstract":"<div><div>An analytical solution for the coolant flow reversal process in the core of the <strong>T</strong>singhua <strong>H</strong>igh <strong>F</strong>lux <strong>R</strong>eactor (THFR) following the loss of forced circulation is developed based on thermal-hydraulic feedback. In this scenario, the coolant reverses direction driven by buoyancy forces generated within the core. Key factors influencing this process are systematically analyzed. Both theoretical analysis and computational fluid dynamics (CFD) simulations indicate that the time required for flow reversal is primarily influenced by the coolant channel width and coolant viscosity. The final natural circulation flow velocity is determined by the coolant channel width, coolant viscosity, and reactor power level. The additional driving head provided by the residual heat removal system responds more slowly and with lower magnitude compared to the core's inherent thermal-hydraulic feedback. Among the influencing parameters, the coolant channel width has the most significant impact on both the final flow rate and the reversal speed. Additionally, the presence of unheated regions in the fuel assemblies slightly reduces the final circulation flow rate. For future reactor designs, it is essential to tightly control the machining and assembly tolerances of fuel assemblies and minimize the rotational inertia of emergency pumps to facilitate faster flow reversal in the core.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103861"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary transmutation design on the concept of multi-beam accelerator driven system","authors":"Xiaochong Zhu ,&nbsp;Xiaoqiang Wei ,&nbsp;Guopeng Sun ,&nbsp;Yuanshuai Qin ,&nbsp;Xiaobo Li ,&nbsp;Neng Pu ,&nbsp;Xinyuan Luo ,&nbsp;Xunchao Zhang ,&nbsp;Hanjie Cai ,&nbsp;Huan Jia ,&nbsp;Yuan He","doi":"10.1016/j.net.2025.103895","DOIUrl":"10.1016/j.net.2025.103895","url":null,"abstract":"<div><div>The Multi-Beam Accelerator-Driven System (MB-ADS) offers improvements over single-beam designs by distributing proton beams across multiple target assemblies via beam-splitting technology, thereby achieving enhanced neutronic performance. This study performed a comparative burnup transmutation analysis between the proposed MB-ADS and conventional single-beam system, demonstrating that the MB-ADS exhibits a distinct advantage in flattening the core power distribution during the burnup process. Building on the MB-ADS design, this study further developed a transmutation scheme for minor actinides (MAs) and conducted a comprehensive burnup analysis. Key parameters—including reactivity, beam current, isotope masses, and the maximum assembly power peaking factor—were calculated during the transmutation burnup process. The results validated two distinct advantages of the MB-ADS design: superior burnup stability and high-efficiency transmutation capability.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103895"},"PeriodicalIF":2.6,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adsorption characteristics of tritium in lithium vacancy for Li4SiO4: A density functional theory study","authors":"Siman Li ,&nbsp;Mouhao Wang ,&nbsp;Shanshan Bu ,&nbsp;Bing Zhou ,&nbsp;Baoping Gong ,&nbsp;Zhenzhong Li ,&nbsp;Deqi Chen","doi":"10.1016/j.net.2025.103894","DOIUrl":"10.1016/j.net.2025.103894","url":null,"abstract":"<div><div>Lithium orthosilicate (Li₄SiO₄) is a promising breeder material with its high lithium density and low tritium retention for fusion reactor blanket. After neutron irradiation, Li₄SiO₄ not only produces tritium but also forms lithium vacancy defects, which may significantly influence the release and collection of tritium. Therefore, in this paper, the adsorption characteristics of tritium in different lithium vacancy defects of Li₄SiO₄ were systematically studied based on first principles to understand the influence mechanism of lithium vacancies on tritium. Tritium breeder materials are exposed to a flowing mixed-gas atmosphere of helium and hydrogen. In this typical oxygen-poor (O-poor) operational environment, the formation energies were investigated. For comparison, oxygen-rich (O-rich) conditions were also considered. The formation energies, possible adsorption sites and electronic properties of defects were analyzed by constructing lithium vacancy models and tritium adsorption models. It was found that the formation energies of lithium vacancies (V_Li) under O-rich conditions were 1.21–2.16 eV compared with the lithium vacancy-tritium defect complexes (V_Li-T) of 0.52–1.12 eV, which indicates that V_Li-T is easier to form than V_Li under the same conditions. Additionally, the adsorption energies of tritium in V_Li range from −7.021 to −5.581 eV, showing that V_Li has a strong tritium capture ability. Subsequently, by analyzing multiple possible adsorption sites, it was determined that the octahedral V_Li-T configuration, with an average formation energy of 1.24 eV, is more difficult to form. Finally, electronic property analysis suggested that tritium interacts with the 2p orbital of oxygen to form V_Li-T. The study presented in this paper will provide practical guidance for optimizing tritium breeder materials and designing tritium blankets in the future.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103894"},"PeriodicalIF":2.6,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 comprehensive characterization of a multi-axis ion chamber array for use as a linear accelerator QC device","authors":"Lorenzo Radici ,&nbsp;Valeria Casanova Borca ,&nbsp;Alessandro Garello ,&nbsp;Edoardo Petrucci ,&nbsp;Jacopo Franzino ,&nbsp;Marina Paolini ,&nbsp;Maria Rosa La Porta ,&nbsp;Massimo Pasquino","doi":"10.1016/j.net.2025.103873","DOIUrl":"10.1016/j.net.2025.103873","url":null,"abstract":"<div><h3>Background</h3><div>To investigate the behavior of a high-resolution multi-axis ion chamber array in measuring key parameters within a linear accelerator quality control (QC) program.</div></div><div><h3>Methods</h3><div>The detector consists of a double-layer ionization chamber matrix detection plate and it can acquire relative dose profile in inline and crossline direction. It was tested for reproducibility, dose rate dependence, linearity, and angular/field dependence. Its ability to measure flatness, symmetry, and dose profiles for photon (6/10 MV, FF/FFF) and electron (6/9 MeV) beams was compared against water phantom measurements. The ability to detect multileaf collimator (MLC) positioning errors was also analyzed.</div></div><div><h3>Results</h3><div>Short and long-term reproducibility were within 0.3 %, dose rate dependence was under 0.2 %, and the dose response was linear. The angular dependence was below 1 % for gantry angles between 0° and ±30°. Profile comparisons showed a maximum difference of 1.5 % over beam flat area. Average deviations were minimal for flatness (&lt;0.2 %), symmetry (&lt;0.4 %), and penumbra (&lt;0.7 mm). Depth dose differences did not exceed 1 %. The system can detect MLC positioning error lower than 1 mm.</div></div><div><h3>Conclusions</h3><div>The high resolution multi-axis ion chamber array is a reliable tool for verifying beam parameters in a QC program, demonstrating high accuracy in profile evaluation.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103873"},"PeriodicalIF":2.6,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-functional Dual-arm actuator system design for Tokamak divertor maintenance","authors":"Ruochen Yin ,&nbsp;Yong Cheng ,&nbsp;Zhonghua Wang ,&nbsp;Si Chen ,&nbsp;Hongtao Pan","doi":"10.1016/j.net.2025.103860","DOIUrl":"10.1016/j.net.2025.103860","url":null,"abstract":"<div><div>During the remote handling maintenance of the divertor in the China Fusion Engineering Test Reactor (CFETR), a significant gap was observed between the repeatability performance of the CFETR Multipurpose Overload Robot (CMOR)—a key component—and the actual maintenance requirements. To address this issue, a dual-arm system is proposed in this paper, designed to carry various tools and fulfill a range of high-precision maintenance tasks. This dual-arm system supports rapid tool changes using a robotic tool changer and integrates intelligent maintenance algorithms aided by multiple sensors. A simulation environment was developed, and trajectory tracking experiments were conducted. The results indicate that the dual-arm system can meet the precision requirements of maintenance operations. Additionally, a stress analysis of the system’s key components was carried out using simulation software, followed by experiments in a real-world environment. The experimental results closely matched the simulation outcomes, demonstrating high reliability and suitability for engineering applications.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 1","pages":"Article 103860"},"PeriodicalIF":2.6,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}