{"title":"Verification of the ability of safe activation of the isolated DHR loop of the ALLEGRO reactor in the event of an accident with complete loss of power","authors":"Pavel Zácha, Václav Železný","doi":"10.1016/j.net.2025.103734","DOIUrl":"10.1016/j.net.2025.103734","url":null,"abstract":"<div><div>The development of the ALLEGRO gas-cooled demonstration reactor dates back to the early days of Generation 4 reactors. A more detailed conceptual design is currently being developed, which includes thermohydraulic studies of the reactor's safety features. One of the key components is the emergency residual heat removal system provided by the Decay Heat Removal loop.</div><div>The proper operation of the DHR loop in a total loss of supply accident is strongly dependent on the initial phase of the accident, when helium stagnating throughout the loop volume creates a barrier to the start of its natural circulation in the loop.</div><div>This paper analyze in detail the 3D behavior of the isolated DHR loop both during the normal reactor operation and the operability of the system during the defined accident conditions. The results of the study confirm that the DHR system is designed to be able to safely start the reactor cooling process using natural circulation upon its activation and subsequently cool the hot helium continuously using the DHR exchanger.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 11","pages":"Article 103734"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307765","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":"Method to estimate communication error probabilities based on speech acts for nuclear power plants","authors":"Ilgeun Song , Taewon Yang , Jonghyun Kim","doi":"10.1016/j.net.2025.103740","DOIUrl":"10.1016/j.net.2025.103740","url":null,"abstract":"<div><div>Communication errors contribute to safety in nuclear power plants (NPPs), yet they are not explicitly analyzed in conventional human reliability analysis. This limitation makes it challenging to estimate communication error probabilities (CEPs), which play a significant role in understanding human failure events. Current approaches rely on qualitative assessments or lack statistical foundations, impeding the quantification of CEPs in both intra-organizational and inter-organizational communication. To address this, this study proposes a speech act–based method for estimating CEPs in NPP operations. In this method, communication is categorized into five speech acts—Request, Report, Declaration, Acknowledgement, and Recovery—and a procedural communication sequence diagram is developed to model communication sequences, with a specific equation introduced for CEP calculation. To support this calculation, speech act error probabilities are estimated through statistical analysis of observations on simulator training for intra-organizational communication and expert elicitation for inter-organizational communication. A case study was conducted to demonstrate the applicability of the proposed method, analyzing operator failures in starting the high-pressure safety injection system, representing intra-organizational communication, and in deploying a 1 MW mobile gas turbine generator, representing inter-organizational communication. Additionally, performance shaping factors influencing both intra- and inter-organizational CEPs are discussed, providing a foundation for future research.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 11","pages":"Article 103740"},"PeriodicalIF":2.6,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322681","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":"Numerical analysis of residual stress in the bending process using kinematic isotropic hardening models for a helical tube in SMR and a U-bent tube in PWR","authors":"Kyucheol Jeong , Jae-Yoon Jeong , Hyun-Suk Nam , Hyung-Doh Roh , Kwanghyun Ahn , Jonghun Yoon","doi":"10.1016/j.net.2025.103737","DOIUrl":"10.1016/j.net.2025.103737","url":null,"abstract":"<div><div>This study compares the residual stresses in steam generator tubes used in nuclear reactors—specifically, a U-tube in conventional pressurized water reactor (PWR) and a helical tube in small modular reactors (SMR). With the U-bend radius held constant, tube thickness and helical geometry were varied. Finite element analysis, employing the Yoshida-Uemori kinematic hardening model with Swift isotropic strain hardening law, was conducted to simulate the forming processes and evaluate residual stress distributions. The analysis shows that while the effective strains predicted by pure bending theory closely match the simulation results, differences in plastic deformation and stress evolution arise from the distinct deformation histories. The helical tube exhibits similar residual stresses compared to the U-tube for all thickness and helical geometry, implying that the same heat treatment process may be applicable to both designs.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103737"},"PeriodicalIF":2.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271355","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}
Woosung Kim, Jonghyeok Lee, Jiyong Shim, Sanghyun Cho, Hyosung Cho
{"title":"Fuzzy logic-based filtering for defect detection in automated X-ray inspection during the production of lithium-ion battery pouch cells","authors":"Woosung Kim, Jonghyeok Lee, Jiyong Shim, Sanghyun Cho, Hyosung Cho","doi":"10.1016/j.net.2025.103739","DOIUrl":"10.1016/j.net.2025.103739","url":null,"abstract":"<div><div>This paper presents a fuzzy logic-based filtering method for improving defect detection in two-dimensional (2D) automated X-ray inspection (AXI), a nondestructive imaging technique widely used in the inline quality control of lithium-ion batteries (LIBs) during manufacturing. Enhancing the accuracy of defect detection in 2D AXI is crucial for ensuring battery safety; hence, the proposed method combines the outputs of three conventional detection algorithms with a rule-based fuzzy filtering strategy to generate robust defect maps. Experiments were conducted on various types of defects in LIB pouch cells to demonstrate the feasibility of the algorithm. The proposed method significantly improved the detection accuracy, with processing times meeting the strict requirements for inline inspection, as confirmed by qualitative and quantitative evaluations. Specifically, the method achieved a Dice similarity coefficient of 0.98 and an intersection over union of 0.94 for globular foreign material detection, representing improvements of ∼4.3 and 6.8 %, respectively, over conventional algorithms. Furthermore, it achieved an average inference speed of 0.84 frames per second, which is 5.3 times faster than a recent comparative approach. Thus, the proposed method offers a high detection accuracy and practical efficiency, rendering it suitable for industrial deployment in automated inspection systems.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103739"},"PeriodicalIF":2.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271356","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}
Mathew Adefusika Adekoya , Shuhuan Liu , Tian Xing , Junye Zhou , Xuan Wang , Haowei Li , Yunfeng Sun , Chao Wang , Ximin Zhang , Huawei Sheng , Xinkun Li , Xiaotang Ren
{"title":"Degradation of the SiGe MMIC LNAs induced by 30 MeV carbon ion irradiation under different bias conditions","authors":"Mathew Adefusika Adekoya , Shuhuan Liu , Tian Xing , Junye Zhou , Xuan Wang , Haowei Li , Yunfeng Sun , Chao Wang , Ximin Zhang , Huawei Sheng , Xinkun Li , Xiaotang Ren","doi":"10.1016/j.net.2025.103705","DOIUrl":"10.1016/j.net.2025.103705","url":null,"abstract":"<div><div>The SiGe MMIC Low Noise Amplifier (LNA) model BGU7005, fabricated using NXP Semiconductors' QUBiC4 process, is a high-performance amplifier designed for Global Navigation Satellite System (GNSS) applications. We investigate the impact of 30 MeV C<sup>5+</sup> ions irradiation at a fluence of 1 × 10<sup>11</sup> ions cm<sup>−2</sup> on SiGe MMIC LNAs under different conditions. The BGU 7005, operating within 1.5 V–3.1 V voltage supply, was subjected to three conditions: floating, 3V voltage supply, and 3V voltage supply coupled with electromagnetic interference (3V + EMI). The results showed significant post-radiation degradation in key Radio Frequency (RF) parameters. The (3V + EMI) bias condition provides moderate signal transmission and greater stability across the frequencies. However, the floating condition significantly suffers more degradation because of the charge trapping and defect formation. The noise figure (NF) achieves its lowest noise value between 1.5 GHz and 1.6 GHz, beyond 1.6 GHz, radiation exposure increases the noise, particularly affecting the floating and 3V biases. These findings underscore the vulnerability of these devices to radiation-induced damage, particularly in harsh environments. The study highlights that optimized biasing strategies, such as the 3V + EMI condition, are key to mitigating radiation degradation and enhancing LNA reliability in space.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103705"},"PeriodicalIF":2.6,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195945","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}
H. Hu , Y. Wang , H.J. Xu , Y.F. Zeng , T.N. Hu , H.M. Wang , G.Y. Feng , Y.J. Pei
{"title":"Analysis and optimizations of macro-pulse performances for a constructed high-power beam injector with a compact layout","authors":"H. Hu , Y. Wang , H.J. Xu , Y.F. Zeng , T.N. Hu , H.M. Wang , G.Y. Feng , Y.J. Pei","doi":"10.1016/j.net.2025.103730","DOIUrl":"10.1016/j.net.2025.103730","url":null,"abstract":"<div><div>The performance of terahertz (THz) radiation from free electron lasers (FEL) depends on the consistency of electron bunches within the macro-pulse, not just the properties of individual bunches. In accelerator-based injectors, bunch-to-bunch deviations often arise due to transient beam loading effects. This study investigates the impact of such transient responses on macro-pulse inconsistencies by combining theoretical analysis and particle simulations, using the FEL injector at Huazhong University of Science and Technology (HUST) as a case study. The goal is to optimize macro-pulse performance without requiring additional equipment or facility upgrades. To achieve this, an improved multi-objective optimization algorithm, NSGA-III, is introduced to optimize RF injection timing and phase settings, targeting energy and phase consistency within the macro-pulse and stable energy output. The approach is validated through extensive virtual simulations, which demonstrate its effectiveness in providing optimal initial settings for the HUST-FEL injector's macro-pulse. Subsequent online experiments conducted on this injector have preliminarily validated the reliability of the proposed method as well. The results are applicable to other multi-bunch/macro-pulse injectors, offering a cost-effective solution for efficient beam commissioning and engineering implementation.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103730"},"PeriodicalIF":2.6,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271354","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}
Dayang Wang , Yu Zhang , Yanhu Ding , Mingxin Bai , Zhulin Nie
{"title":"Experimental study on the minimum limit anchorage length and mechanical properties of bent anchorage steel bars in reactor building","authors":"Dayang Wang , Yu Zhang , Yanhu Ding , Mingxin Bai , Zhulin Nie","doi":"10.1016/j.net.2025.103733","DOIUrl":"10.1016/j.net.2025.103733","url":null,"abstract":"<div><div>This study presents a comprehensive investigation into the anchorage performance of bent steel bars embedded in straight segments of reinforced concrete (RC) specimens with high reinforcement ratios, using a prototype nuclear reactor shear wall as the reference model. A total of 44 pull-out tests, grouped into nine series, were conducted to determine the minimum effective anchorage length. Key failure mechanisms, bond behavior, and strain development were systematically analyzed. The results indicated that with decreasing anchorage length, no pull-out failure occurred; instead, steel bar fracture became the dominant failure mode. The minimum effective anchorage length was identified as 0.25l<sub>a</sub>b<sub>e</sub>, below which anchorage performance was significantly compromised. At this critical length, the incorporation of structural transverse reinforcement increased the average maximum yield load by 4.96 %, whereas variations in bent bar length exhibited minimal influence. Furthermore, high reinforcement ratios enhanced the deformation capacity of the specimens, reducing the likelihood of premature yielding. Specimens without transverse reinforcement exhibited a 32.08 % reduction in average yield displacement (9.95 mm) compared to those with transverse reinforcement. An empirical regression model was developed to modify the bond strength calculation under high reinforcement conditions, exhibiting strong predictive accuracy and aligning closely with experimental observations. The findings offer practical insights for the anchorage design of RC specimens in nuclear facilities, especially under conditions of dense reinforcement where existing code provisions may be inadequate.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103733"},"PeriodicalIF":2.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255099","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":"Influence of internal heat generation on heat transfer in an MSR heat exchanger under laminar flow condition","authors":"Dong-Hyuk Park, Bum-Jin Chung","doi":"10.1016/j.net.2025.103736","DOIUrl":"10.1016/j.net.2025.103736","url":null,"abstract":"<div><div>A prominent feature of Molten Salt Reactor (MSR) is that the Internal Heat Generation (IHG) occurs within the fluid, as the nuclear fuel is dissolved in the coolant. This renders the energy equation non-homogeneous, requiring different mathematical approach. However, studies that quantitatively analyze the influence of IHG are limited. Especially, in the heat exchanger the IHG occurs coincide with wall cooling. Therefore, we analyzed the influence of IHG on a laminar pipe under wall cooling condition. Based on the superposition principle, the original problem is decomposed into two simpler boundary-layer sub-problems. The presence of IHG increased heat transfer rate and its influence increased with the magnitude of the IHG. Under uniform wall temperature condition, after sufficient flow development, the fluid temperature becomes constant exhibiting a conduction-like behavior, whereas under uniform heat flux condition, the fluid temperature increased despite heat transfer to the wall, superficially resembling a reverse heat transfer. Using the calculated data, the new heat transfer correlations were developed to incorporates the influence of IHG. The correlations were then applied to performance evaluations of MSR heat exchangers. It concludes that neglecting the IHG could lead to an underestimation of total heat transfer rate by up to 26 %. The findings offer a quantitative basis for considering IHG impact in future MSR heat exchanger design.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103736"},"PeriodicalIF":2.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271281","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":"Nonlinear structural analysis for structural integrity re-evaluation of existing spent fuel pool in nuclear power plant under beyond design basis earthquake","authors":"Ting-Yu Fan, Chin-Yu Lin, Hsoung-Wei Chou","doi":"10.1016/j.net.2025.103723","DOIUrl":"10.1016/j.net.2025.103723","url":null,"abstract":"<div><div>This paper presents reevaluation of structural integrity for an existing spent fuel pool (SFP) of the pressurized water reactor power plant in Taiwan, as well as to investigate the locations of potential weaknesses in the whole structure under beyond design basis earthquake (BDBE). In addition, the partial cracking effect from BDBE was also considered in this study associated with higher damping ratio and reduced flexural rigidity. At first, the analysis procedure for single wall based on the structural analysis standards and equivalent seismic load assessment introduced in EPRI-3002009564 and ACI 350.3–06 was considered. All structural crucial aspects considered relevant were included in the analyses: the concrete structure, the steel liner, its connections and the containing fluid. Then, evaluations considering more detailed SFP structure and comprehensive loading combinations were conducted and compared. The analyses results reveal that the structural responses raise significantly when considering increasing the damping ratio and reducing the rigidity of the structure. Furthermore, it is found that the most severely damaged location in the SFP structure is on the south wall, because lateral force on the south wall is larger than others. However, even in this case, the steel liner can still maintain the structural integrity under BDBE.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103723"},"PeriodicalIF":2.6,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263784","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":"Path planning of RRT* algorithm with subregional dynamic probabilistic sampling based on artificial potential field in radiation environments","authors":"Yanjun Wang, Jinjia Cao, Xiaochang Zheng, Yulong Zhang, Yadong Zhang, Wei Chen","doi":"10.1016/j.net.2025.103706","DOIUrl":"10.1016/j.net.2025.103706","url":null,"abstract":"<div><div>An improved path planning method, ASD-RRT*, is proposed to address the path planning problem in complex static radiation environments. First, the artificial potential field (APF) method is introduced to optimize the RRT* algorithm, guiding the RRT* tree nodes to shift away from the radiation sources. Next, a subregional dynamic probabilistic sampling strategy is employed, improving the goal-directedness of the path search process while considering the effects of radiation dose. Finally, the Douglas-Peucker algorithm is used to smooth the path. This study builds radiation fields using Geant4, simulates multiple radiation scenarios, and performs path planning using A*, PRM, APF-PRM, RRT*, and ASD-RRT* algorithms. The research results indicate that the ASD-RRT* algorithm performs better in navigating narrow regions and excels in complex radiation environments. It can find a safer path with the lowest cumulative dose within a reasonable time, providing a reference solution for path planning in radiation field environments.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 10","pages":"Article 103706"},"PeriodicalIF":2.6,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177822","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}