Nuclear Engineering and Technology最新文献

{"title":"Probabilistic estimation of containment failure modes in Level 2 PSA: Realistic approach and risk implications","authors":"Kwang-Il Ahn","doi":"10.1016/j.net.2025.103847","DOIUrl":"10.1016/j.net.2025.103847","url":null,"abstract":"<div><div>A realistic assessment of the probabilities associated with containment failure modes—such as leaks and ruptures—can significantly influence the quality and credibility of Level 2 probabilistic safety assessments (PSAs) for nuclear power plants (NPPs). From this perspective, this paper provides technical backgrounds on the impact of two different approaches to estimating these probabilities: the Rupture-Before-Leak (RBL) assumption, adopted in many existing Level 2 PSAs, and the more realistic Leak-Before-Break (LBB) assumption. Fundamentally, both approaches rely on probabilistic fragility curves developed independently for two distinct failure modes—more specifically leaks and ruptures, whose nominal sizes are predefined. In some situations, a leakage mode smaller than the leak size may be explicitly considered to more realistically assess the Cs-137 100 TBq release-related probabilistic safety goals. The findings from relevant case studies are presented along with key insights, particularly regarding to their implications for Level 2 safety and performance goals such as Large (Early) Release Frequencies (LERF/LRF), and the Cs-137 risk.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103847"},"PeriodicalIF":2.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830707","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":"Evaluation of the in- and ex-vessel neutron fluence distributions in a Siemens/KWU PWR","authors":"Reuven Rachamin ,&nbsp;Astrid Barkleit ,&nbsp;Jörg Konheiser ,&nbsp;Marcus Seidl","doi":"10.1016/j.net.2025.103846","DOIUrl":"10.1016/j.net.2025.103846","url":null,"abstract":"<div><div>Neutron fluence is one of the key parameters required for calculating the extent of the neutron activation levels in a nuclear power plant (NPP). Therefore, it must be estimated with great accuracy. The neutron fluence is often evaluated using Monte Carlo codes, and its accuracy strongly depends on the level of detail in the reactor geometrical model and the representation of the neutron source. For decommissioning planning of NPPs in Germany, a 3D detailed Monte Carlo model of a Siemens/KWU pressurized water reactor (PWR), one of Germany's most common NPP types, was developed to calculate the neutron fluence distributions within the reactor core and its immediate surrounding area. This paper provides a detailed description of the reactor model, validates the accuracy of the model predictions by comparing the calculation results with metal foil-activation measurements, and determines the neutron fluence distribution in selected components and a fine rectangular mesh covering the entire geometry of the reactor model. The paper indicates that the developed Monte Carlo model can be used to obtain the neutron fluence with high accuracy for calculating the activation distribution of the reactor components.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103846"},"PeriodicalIF":2.6,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841419","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":"Overview on the influencing factors of spent nuclear fuel disposal plan for Malaysian research reactor","authors":"Nurul Syakirah Zainal ,&nbsp;Nurul Muyassarah Ibrahim ,&nbsp;Norsyahidah Mohd Hidzir ,&nbsp;Kok Siong Khoo ,&nbsp;Rohyiza Ba'an ,&nbsp;Muhammad Khairul Ariff Mustafa ,&nbsp;Syazwani Mohd Fadzil","doi":"10.1016/j.net.2025.103837","DOIUrl":"10.1016/j.net.2025.103837","url":null,"abstract":"<div><div>Research reactors play a crucial role in the development of nuclear technology, especially for countries that support nuclear energy as an alternative power source, however it has become a major topic of debate due to public concerns and opposition regarding radioactive waste management. Spent nuclear fuel from research reactor, is categorized as high-level radioactive waste. Malaysia is currently advancing in research and development activities through its national research reactor but has not yet developed a disposal plan for spent nuclear fuel from this reactor. With the advancement of nuclear technology in Malaysia, developing a strategic disposal plan for spent nuclear fuel will help support the sustainable growth of nuclear energy and environmental protection. This study aims to identify factors influencing the development of a disposal plan for spent nuclear fuel from research reactors and to establish various disposal plan scenarios for spent nuclear fuel in Malaysia. This review discusses several parameters for developing a disposal plan for spent nuclear fuel from research reactors. The selected scenarios for the disposal plan of spent nuclear fuel from research reactors include geological permanent disposal, permanent borehole disposal, direct permanent disposal, and the “wait-and-see” policy, all of which are discussed in this review.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103837"},"PeriodicalIF":2.6,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864723","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":"Design of special deflection magnet for 120 keV neutral beam injection system","authors":"Hui-hui Hong ,&nbsp;Yuan-lai Xie ,&nbsp;Kun Tian ,&nbsp;Xian-dong Liu ,&nbsp;Bin Li ,&nbsp;Li-zhen Liang ,&nbsp;Qian-xu Wang ,&nbsp;Fang Wang ,&nbsp;Yang Zhu ,&nbsp;Yue Yun ,&nbsp;Hao-ran Xie","doi":"10.1016/j.net.2025.103844","DOIUrl":"10.1016/j.net.2025.103844","url":null,"abstract":"<div><div>The magnetic deflection system is a crucial component of the Neutral Beam Injection (NBI) system in magnetic confinement fusion, directly determining the safety and reliability of the entire NBI system. With the increasing requirements for neutral beam injection heating in magnetic confinement fusion, the development of deflection magnet with higher ion deflection efficiency and longer pulse adaptation capabilities has become a key focus of current research. The 80 keV injection beam energy of EAST-NBI faces certain challenges in addressing future high-parameter injection requirements. Under the demands of high energy, long pulse, and multiple beam currents, this paper proposes a novel deflection magnet design at 120 keV parameters. A detailed three-dimensional model of a specially-shaped deflection magnet based on six D⁺ beam source channels is developed. Additionally, the deflection performance of stray ions and the thermal-mechanical behavior of high-heat-flux components are analyzed. Finite element analysis has been employed to systematically investigate the trajectories of 120 keV mixed-energy particle beams through the deflection magnet and the corresponding three-dimensional spatial magnetic field distribution. Simulation results confirm that high-energy stray ions undergo effective magnetic deflection and are fully intercepted by the optimized ion dump structure. Concurrent thermo-mechanical analysis of high-heat-flux components reveals peak operational temperatures of 214 °C and maximum equivalent thermal stresses of 113 MPa, both well below the material safety limits. The integrated analysis of magnetic field distribution, beam trajectory, and thermo-mechanical results demonstrate that the proposed deflection magnet design successfully fulfills multi-objective requirements for residual ion management in high-power neutral beam injection systems. Moreover, the system exhibits robust operational stability under extended pulse durations, confirming its readiness for experimental deployment following manufacturing and commissioning phases.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103844"},"PeriodicalIF":2.6,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864878","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":"Experimental study on natural circulation cooling system for core catcher with downward-facing heating channel","authors":"Seokgyu Jeong,&nbsp;Byeonghee Lee,&nbsp;Jun-young Kang,&nbsp;Seong Ho Hong,&nbsp;Chang Wan Kang,&nbsp;Jin Hyeok Kim","doi":"10.1016/j.net.2025.103845","DOIUrl":"10.1016/j.net.2025.103845","url":null,"abstract":"<div><div>Core catchers are severe accident mitigation devices designed to prevent containment failure in nuclear power plants. In Korea, certain export-oriented nuclear reactors have adopted the PECS (Passive Ex-vessel corium retaining and Cooling System) core catcher design. This study investigates the cooling performance of this conceptually designed core catcher, PECS, using a scaled experimental facility, VPEX (Variable PECS EXperimental facility). The results showed that the cooling performance was satisfactory at an average heat flux value of 232 kW/m2, which is 1.75 times higher than predicted heat flux value. Furthermore, hydraulic and heat transfer characteristics for large-scale downward-facing heating channels were analyzed. It was observed that the large-scale facility exhibited relatively low heat transfer coefficient values compared to common laboratory scale facilities. Lower inlet pressures and less subcooling enhanced natural circulation mass flow rates and void fractions. Variations in inlet pressure, subcooling, or heat flux had minimal impacts on surface heat transfer characteristics such as boiling curves or heat transfer coefficients. Based on these experimental findings, the NCir (Natural Circulation calculator) analysis code was developed. The Wallis model provided the most accurate predictions for void fraction and natural circulation mass flow rate calculations. The experimental results and prediction code have potential applications in future PECS analyses. Additionally, they serve as fundamental data for large-scale facilities with downward-facing heating structures similar to VPEX.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103845"},"PeriodicalIF":2.6,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827628","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":"Large language model agent for nuclear reactor operation assistance","authors":"Yoon Pyo Lee ,&nbsp;Joowon Cha ,&nbsp;Yonggyun Yu ,&nbsp;Seung Geun Kim","doi":"10.1016/j.net.2025.103842","DOIUrl":"10.1016/j.net.2025.103842","url":null,"abstract":"<div><div>This study proposes an artificial intelligence (AI) driven approach to nuclear reactor operation, focusing on a novel large language model (LLM) agent system designed to assist operators with various tasks within a nuclear reactor simulator. Previous studies have demonstrated the potential of deep learning for tasks such as anomaly detection and heat-up mode automation. Building on these efforts, studies have been conducted to employ LLMs for nuclear reactor diagnostics and the automation of system engineering tasks. The emergence of AI agents that utilize external tools, capable of natural language reasoning and retrieval-augmented generation, offers broader opportunities for decision-making and operation. We developed an AI agent architecture that integrated documentation, functions, and other modules. Two experiments were conducted to demonstrate the usefulness and potential of the proposed system. The first experiment evaluated whether the AI agent could address a boron concentration anomaly using a predictive module and relevant documentation. The second experiment evaluated whether the AI agent could generate a new procedure that parallels the provided manual without additional model training. The results indicate that the AI agent can execute commands and adapt the operational parameters, thereby demonstrating a comprehensive approach to automated reactor operations for safer, cost-effective performance.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103842"},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830705","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":"Comparative thermodynamic assessment of pyroprocessing and chlorination for the treatment of LWR spent nuclear fuel","authors":"Jin-Mok Hur,&nbsp;Hunsuk Im,&nbsp;Chang Hwa Lee","doi":"10.1016/j.net.2025.103839","DOIUrl":"10.1016/j.net.2025.103839","url":null,"abstract":"<div><div>The disposal burden of spent nuclear fuel (SNF) can be reduced by processing it to separate and collect constituent nuclides based on their characteristics. This study evaluates and compares the treatment efficiencies of pyroprocessing and chlorination, based on thermodynamic equilibrium calculations, using light water reactor (LWR) SNF, from which volatile fission products have been removed through high-temperature heat treatment, as the reference material. Pyroprocessing, consisting of oxide reduction (OR), electrorefining (ER), and electrowinning (EW), was effective not only in separating high-decay-heat, short-lived fission products (FPs) from LWR SNF but also in group recovery of transuranic elements (TRUs) that can be recycled as nuclear fuel. The chlorination process, which involves chlorination with NH₄Cl, followed by precipitation with Li₂CO₃ in LiCl-KCl molten salt, was effective in separating high-decay-heat, short-lived FPs from LWR SNF. A hybrid process integrating the EW step of pyroprocessing and the NH₄Cl chlorination step of the chlorination process was proposed in this study. Thermodynamic analysis indicates its effectiveness in high-decay-heat, short-lived FPs separation and group recovery of TRUs, demonstrating its potential as a viable option to reduce the disposal burden of high-level waste.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103839"},"PeriodicalIF":2.6,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827627","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":"ANN-based pulse shape discrimination for background reduction in neutron depth profiling","authors":"Hwijoon Jeong ,&nbsp;Jinhwan Kim ,&nbsp;Byung Gun Park ,&nbsp;Kyung Taek Lim","doi":"10.1016/j.net.2025.103816","DOIUrl":"10.1016/j.net.2025.103816","url":null,"abstract":"<div><div>This study presents an artificial neural network (ANN)-based pulse shape discrimination (PSD) algorithm developed to enhance the accuracy of neutron depth profiling (NDP) analysis in solid-state electrolytes (SSEs). A key innovation of the proposed approach lies in effectively suppressing low-energy background signals, which typically compromise analytical precision. To overcome labeling challenges in the low-energy region, the training data was augmented with white noise, enhancing the ability of the model to discriminate the emulated low-energy signals. Compared with the conventional rise-time method, the ANN-based PSD algorithm demonstrated a 77 % higher area under the curve value indicating higher discrimination performance. Furthermore, explainable artificial intelligence techniques were employed to interpret and evaluate the performance of the algorithm. This underscored the reliability and potential of ANN-based PSD in advancing the high precision of NDP analysis of SSEs.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103816"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773195","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":"Experimental and numerical study on seismic behavior of SSC slab-RC wall joints in NPP","authors":"Junpeng Ye ,&nbsp;Ming Zhao ,&nbsp;Xiaodong Du ,&nbsp;Xing Wang ,&nbsp;Haitao Xu ,&nbsp;Yongshan Zhang ,&nbsp;Dayang Wang","doi":"10.1016/j.net.2025.103830","DOIUrl":"10.1016/j.net.2025.103830","url":null,"abstract":"<div><div>A new type of single steel-plate concrete slab-reinforced concrete wall joint (SSCSWJ) is proposed to enhance the seismic performance of slab-wall joints (SWJs) in nuclear power plants (NPPs). Based on a typical side SWJ in NPPs, three 1:3 reduced scale SWJ specimens were designed and fabricated: one reinforced concrete slab-wall joint (RCSWJ) specimen as a reference, and two SSCSWJ specimens (SSCSWJ1, SSCSWJ2). Low cyclic loading tests were conducted to evaluate and compare the seismic performance of the three specimens. A finite element model (FEM) was developed and validated against the experimental results. Subsequently, a parametric analysis was performed on SSCSWJ1 to investigate the influence of critical design parameters. Test results indicate that, compared with RCSWJ, both SSCSWJ1 and SSCSWJ2 exhibit enhanced bearing capacity, ductility, and energy dissipation, and also have the potential to improve construction efficiency. The parametric study further reveals that increasing the slab reinforcement ratio effectively enhances both the initial stiffness and bearing capacity of SSCSWJ1. Within the studied parameter range, increasing the steel-plate thickness improves the initial stiffness and has minimal influence on bearing capacity, whereas T-section steel spacing and concrete grade exert relatively limited effects on both.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103830"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144779392","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":"Zirconium hydride thermal scattering law","authors":"I. Švajger ,&nbsp;N.C. Fleming ,&nbsp;A.I. Hawari ,&nbsp;B. Laramee ,&nbsp;G. Noguere ,&nbsp;L. Snoj ,&nbsp;A. Trkov","doi":"10.1016/j.net.2025.103834","DOIUrl":"10.1016/j.net.2025.103834","url":null,"abstract":"<div><div>The aim of this paper is to evaluate the thermal neutron scattering properties of zirconium hydride (ZrH_x) with particular emphasis on the ε-phase (x = 2) and the δ-phase (x = 1.5). The methodology involved performing density functional theory calculations using the VASP code to obtain the force constants. Subsequently, the Phonopy and NJOY codes were used to analyse the lattice dynamics and thermal scattering properties. The main results of this investigation include a detailed study of the atomic structures, mechanical properties, phonon density of states, thermal scattering cross sections and benchmark results. These results are compared with other calculations from the literature and experimental measurements. The assessment at the Jožef Stefan Institute (JSI) generally reduces the discrepancies in benchmark results, but certain inconsistencies remain. The addition of the data for zirconium bound in ZrH to the analysis has no appreciable effect on the benchmark results.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 12","pages":"Article 103834"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840638","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}