Annals of Nuclear Energy最新文献

{"title":"Operational strategy and impact analysis of single train isolation in high pressure heater system for generation III pressurized water reactors","authors":"Xu Jiaoshen ,&nbsp;Qin Ge ,&nbsp;Li Dongyuan ,&nbsp;Liu zhiyun ,&nbsp;Wang Ming ,&nbsp;Li Qiang","doi":"10.1016/j.anucene.2025.111901","DOIUrl":"10.1016/j.anucene.2025.111901","url":null,"abstract":"<div><div>This study focuses on the single train isolation scenario in the High Pressure Heater system (AHP) of the HPR1000 reactor. A long-term operation strategy is proposed, which involves reducing the unit power to 92% of its rated capacity. To demonstrate the feasibility of this strategy and assess its safety impact, the impacts of AHP system isolation on operational parameters are analyzed based on the operational characteristics. Combined with multiple impacts on the reactor and phenomena observed in design basis conditions (DBCs), specific accident conditions requiring quantitative analysis are identified. Through quantitative evaluations and safety analysis results of related equipment, the feasibility of the operational strategy is demonstrated. The proposed strategy avoids reactor fallback and enhances operational economy. The methodology and conclusions provide technical references for similar scenarios in Generation III pressurized water reactor nuclear power plants.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111901"},"PeriodicalIF":2.3,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145216784","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":"Dynamic response characteristics of DHRS in small pressurized water reactor under SGTR accident","authors":"Xiaojun Qiu ,&nbsp;Xiangbin Li ,&nbsp;Yusheng Liu ,&nbsp;Chengshen Wang ,&nbsp;Dechen Zhang","doi":"10.1016/j.anucene.2025.111900","DOIUrl":"10.1016/j.anucene.2025.111900","url":null,"abstract":"<div><div>Small modular reactors (SMRs) are considered a promising direction for the future development of nuclear power generation due to their enhanced safety, lower initial costs, shorter construction periods, and flexible deployment options. Some typical reactors ensure robust performance during both normal operation and accident scenarios by employing passive safety mechanisms. To further understand the capabilities of these passive safety systems, based on the NuScale integral pressurized water reactor, a simulation model was developed using RELAP5 code to analyze the thermal–hydraulic response characteristics of the decay heat removal system (DHRS) during a steam generator tube rupture (SGTR) accident. The results show that the decay heat removal heat exchanger (DHRHX) can eliminate the core decay heat and effectively control the core inlet and outlet temperatures. When the water level in the primary loop drops below the baffle of the pressurizer, significant flow oscillations will occur, triggering fluctuations in other parameters.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111900"},"PeriodicalIF":2.3,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154733","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":"Simulation of severe accidents in sodium-cooled fast reactors using ASTRA code with a molten clad motion model","authors":"Yadu Narendran,&nbsp;K. Natesan,&nbsp;A. John Arul,&nbsp;A. Jasmin Sudha","doi":"10.1016/j.anucene.2025.111894","DOIUrl":"10.1016/j.anucene.2025.111894","url":null,"abstract":"<div><div>Accidents in sodium cooled fast reactors such as Unprotected Loss of Flow (ULOFA), and Total Instantaneous Blockage (TIB) involve coolant boiling and molten material motion inside the voided channel. Accurate modeling of molten clad dynamics is required to calculate transient power evolutions, fuel motion modeling, and transition and disassembly phase calculations. In the present study, a one dimensional molten clad motion model is developed. The model is validated with analytical calculations and benchmark experiment data. Integrating the clad motion model, TIB and ULOFA scenarios in a medium sized SFR is analyzed using the ASTRA code. The TIB analysis revealed that fast voiding resulted in rapid power rise and fuel melting. The coolant channel was blocked by the refrozen clad at the lower axial blanket. The parametric study showed that the heat generation rate affects the time of occurrence of key events such as sodium boiling, clad melting, fuel melting. The ULOFA analysis showed a gradual introduction of steel relocation feedback and a complete channel blockage at the top of the fissile region at the time of fuel melting. The parametric study showed that the heat generation rate is the most influential parameter that affects the time of occurrence of key events.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111894"},"PeriodicalIF":2.3,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154732","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-objective optimization study of wire mesh mist eliminator based on RSM and NSGA-II","authors":"Shuting Zhong ,&nbsp;Shaochen Yang ,&nbsp;Rulei Sun ,&nbsp;Ruifeng Tian ,&nbsp;Sichao Tan ,&nbsp;Chaojun Deng ,&nbsp;Bo Wang","doi":"10.1016/j.anucene.2025.111899","DOIUrl":"10.1016/j.anucene.2025.111899","url":null,"abstract":"<div><div>The structural parameters of wire mesh mist eliminator directly affect the separation performance. In this study, based on numerical simulation data, a mathematical model of separation efficiency and pressure drop was constructed by response surface methodology (RSM). Combined with the Non-dominated sorting genetic algorithm II (NSGA-II), the multi-objective optimization was carried out. The correlations of four structural parameters, namely, wire diameter, mesh diameter, layer spacing and number of layers, with separation efficiency and pressure drop was analyzed by Pearson’s coefficient. The results show that the number of layers significantly influences separation efficiency and pressure drop. Reducing wire diameter can increase separation efficiency and decrease pressure drop. The Pareto front solution set shows the trade-off relationship between separation efficiency and pressure drop, providing diverse design options for different engineering requirements. This study provides theoretical basis and methodological support for the design and optimization of wire mesh mist eliminators.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111899"},"PeriodicalIF":2.3,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154727","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":"Dependence assessment of human operators in advanced main control rooms considering uncertainty and dynamic situations","authors":"Xuying Huang ,&nbsp;Haiyong Wang ,&nbsp;Xiaoyan Su","doi":"10.1016/j.anucene.2025.111893","DOIUrl":"10.1016/j.anucene.2025.111893","url":null,"abstract":"<div><div>In human reliability analysis (HRA), dependence assessment is of particular importance, especially in nuclear engineering. For operators in advanced main control rooms (MCRs), many dependence assessment methods are derived from the Technique for Human Error Rate Prediction (THERP), which may lack traceability and repeatability. Moreover, existing studies tend to overlook the dynamic aspects of operator dependence. We propose a combination of decision trees (DTs) and Dempster–Shafer evidence theory (DSET) for assessing operator dependence in advanced MCRs under uncertain, dynamic conditions. Firstly, experts identify influence factors, which analysts then assess against specific conditions. Secondly, analysts model these judgments with DSET and apply Dempster’s rule to fuse evidence and reduce uncertainty. Thirdly, a DT model classifies the operator dependence level, and a modified THERP method calculates the conditional human error probability (CHEP). Finally, a shift-change scenario illustrates dynamic dependence assessment. Case study on a residual-removal system breach demonstrates its practicality and flexibility.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111893"},"PeriodicalIF":2.3,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154800","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":"Development of a transient critical power ratio methodology for cycle specific BWR reload analysis","authors":"I. Clifford ,&nbsp;K. Nikitin ,&nbsp;A. Cherezov ,&nbsp;A. Gorzel ,&nbsp;M. Wolff ,&nbsp;J. Dus ,&nbsp;H. Ferroukhi","doi":"10.1016/j.anucene.2025.111902","DOIUrl":"10.1016/j.anucene.2025.111902","url":null,"abstract":"<div><div>A new framework for generic hot channel transient CPR computations for modern BWR fuel assemblies has been developed with the goal of providing comprehensive independent safety assessments for BWR reload licensing analysis. TRAnsient Cpr analysis Tool (TRACT) is implemented in Python 3, and acts as a wrapper to calculate the critical CPR condition using TRACE as a hot channel code with initial and boundary conditions taken from upstream S3K simulations. TRACT supports subprocess-based (multi-processor) parallelism and MPI parallel execution, such that the transient CPR analyses for a typical BWR reload can be completed within minutes. Using object-oriented code design, new dryout correlations, fuel designs and even new hot channel codes can be introduced using a clean API, with minimal effort, and with little risk of breaking the existing code. The approach also makes it extremely simple to create unit tests for V&amp;V. The V&amp;V of TRACT is an ongoing process. While verification of the implemented correlations has been carried out, basic unit tests have been established, and selected validation has been conducted, this will be continuously extended in the future. A demonstration case has been presented to illustrate the capabilities of the code. Despite independent codes, models and methodologies, transient CPR predictions using TRACT are consistent with vendor results.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111902"},"PeriodicalIF":2.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154731","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":"Two-dimensional numerical analysis of interphase mass transfer in a single bubble under phase change conditions","authors":"Yibin Wang ,&nbsp;Zhuang Miao ,&nbsp;Yu Zhao ,&nbsp;Ruifeng Tian ,&nbsp;Sichao Tan ,&nbsp;Jiming Wen","doi":"10.1016/j.anucene.2025.111892","DOIUrl":"10.1016/j.anucene.2025.111892","url":null,"abstract":"<div><div>Heat and mass transfer at the gas–liquid interface in bubbles plays a crucial role in bubble towers and reactors. In the presence of exothermic reactions or decay heat, the effect of phase change on the motion and mass transfer in bubbles cannot be neglected. In this paper, the mass transfer mechanism of multicomponent bubbles under pairs of phase change conditions is investigated by numerical simulation methods. The results show that evaporation affects the interphase mass transfer through the mechanisms of diluting the iodine concentration within the bubbles and lengthening the iodine diffusion distance. The introduction of decay heat has a large impact on evaporation, which in turn affects the mass transfer. Ultimately, this paper presents a suitable formula for the Sherwood number under evaporation.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111892"},"PeriodicalIF":2.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154728","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":"Coupled multi-physics analysis of low-enriched uranium nuclear thermal propulsion reactors","authors":"Li Wei ,&nbsp;Liu Xiaojing ,&nbsp;Chai Xiang ,&nbsp;Liu Zijing ,&nbsp;Zhao Pengcheng","doi":"10.1016/j.anucene.2025.111897","DOIUrl":"10.1016/j.anucene.2025.111897","url":null,"abstract":"<div><div>The growing demand for high-performance propulsion systems in aerospace has highlighted that current multi-physics coupling technologies cannot accurately assess the performance and safety of low-enriched uranium nuclear thermal propulsion reactors (LEU-NTPRs) under extreme conditions. Accordingly, this study employs advanced multi-physics coupling methods to investigate the performance, safety, and thermoelastic behavior of LEU-NTPR assemblies and their core geometries under several extreme boundary conditions, providing a scientific basis for reactor design. By utilizing OpenFOAM, a multi-region neutron transport-conjugate heat transfer coupling solver is developed to perform pin-by-pin multi-physics coupling calculations for reactor assemblies and full-core geometries. Both the neutron transport and conjugate heat transfer equations are solved, and the resulting steady-state temperature distribution is used as the input for thermoelastic calculations. Thermoelastic analyses are conducted using the solid4Foam solver of OpenFOAM by assuming a small strain to evaluate the displacement and equivalent thermal stress distributions. The assembly coupled simulation shows a significantly improved prediction accuracy for fuel temperature compared to non-coupled methods. Core-coupled simulations confirm that the conceptual design adheres to physical and thermal engineering standards. A thermoelastic analysis reveals that the maximum thermal stress is ∼ 246 MPa, while the maximum fuel displacement reaches 7.1 mm. These findings suggest that thermal stress, particularly in regions with significant temperature gradients, can be a critical factor limiting core power output. By adjusting the core inlet flow rates, the maximum assembly temperature is controlled within safe limits while achieving uniform coolant outlet temperatures. The proposed multi-regional coupling approach enhances the prediction accuracy for the performance, safety, and thermoelastic characteristics of LEU-NTPRs under extreme conditions, while ensuring a high specific impulse in propulsion systems.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111897"},"PeriodicalIF":2.3,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154729","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":"Entropy generation in conjugate mixed convection of a rough cylindrical surface confined within a square chamber under internal heat generation","authors":"Mohammad Shakhawat Khan,&nbsp;Md. Maruf Tahmid,&nbsp;Saad Al Razee,&nbsp;Tawsif Iqbal,&nbsp;Sumon Saha","doi":"10.1016/j.anucene.2025.111898","DOIUrl":"10.1016/j.anucene.2025.111898","url":null,"abstract":"<div><div>This study investigates conjugate mixed convection in a lid-driven cavity containing a rough-walled cylinder with internal heat generation. Three roughness geometries (circular, triangular, square) and different cylinder placements are considered, with the working fluid modeled as a water-ethylene glycol mixture undergoing laminar flow (10³ ≤ <em>Gr</em> ≤ 10⁵, 31.62 ≤ <em>Re</em> ≤ 316.23, 0.1 ≤ <em>Ri</em> ≤ 10). The dynamics of fluid motion and thermal distribution within the solid cylinder and the cavity are dictated by two-dimensional Navier-Stokes and energy equations, which are numerically resolved through the finite element approach. The current study reveals that a circular-shaped rough cylinder positioned at the center of the cavity yields better optimization through <em>ECOP</em> and effectiveness when there is no internal heat generation. With the internal heat generation, thermal transport drops around 10 % at a high <em>Re,</em> whereas the <em>ECOP</em> drops around 70 % for the entire range of parameters. Hence, the other parameter should be optimized to mitigate this adverse situation when the system involves heat generation.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111898"},"PeriodicalIF":2.3,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109120","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 segmented thermoelectric generator optimization method based on interpretable XGBoost and deep generative model","authors":"Tianbao Fang ,&nbsp;Weiliang Jin ,&nbsp;Yinzhou Feng ,&nbsp;Liangliang Lv ,&nbsp;Guohan Gao ,&nbsp;Jieqiong Luo ,&nbsp;Gongping Li ,&nbsp;Nannan Jia","doi":"10.1016/j.anucene.2025.111891","DOIUrl":"10.1016/j.anucene.2025.111891","url":null,"abstract":"<div><div>The implementation of segmented thermoelectric generators (STEGs) can enhance the energy conversion efficiency of radioisotope thermoelectric generators (RTGs). This study proposes a method integrating interpretable XGBoost and Conditional Variational Autoencoder (CVAE) to optimize STEG. An XGBoost regression model trained on validated finite element data predicts electrical performance while Shapley Additive Explanations (SHAP) analysis quantifies parameter impacts. Simultaneously, CVAE was implemented to construct mappings between design parameters and temperature field images to provide visual feedback during the design process. The results demonstrate the XGBoost model achieves exceptional regression performance, and enabling rapid prediction and multi-objective optimization. Based on the optimal design parameters, the CVAE predicts the temperature field image within 2 s, with a structural similarity index (SSIM) of 0.9676. SHAP-based interpretation reveals the key factors affecting electrical performance and provides decision support for optimized parameter selection.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"226 ","pages":"Article 111891"},"PeriodicalIF":2.3,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154730","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}