Progress in Nuclear Energy最新文献

{"title":"Experimental study on polydisperse aerosol removal under multi-parameter spray conditions in containment","authors":"Jiaxuan Tang ,&nbsp;Zhuo Liu ,&nbsp;Luteng Zhang ,&nbsp;Jialong Li ,&nbsp;Yang Yang ,&nbsp;Liangming Pan ,&nbsp;Li Gao ,&nbsp;Yidan Yuan","doi":"10.1016/j.pnucene.2025.105660","DOIUrl":"10.1016/j.pnucene.2025.105660","url":null,"abstract":"<div><div>After LOCA and SGTR accidents in pressurized water reactors, the containment spray system plays a crucial role in mitigating the release of radioactive aerosols suspended in the containment atmosphere. However, for submicron particles with diameters in the range of 0.1–1 μm, the spray removal mechanism exhibits significantly lower collection efficiencies. Investigating the effects of spray characteristics on the minimum attenuation particle size of various submicron aerosol species under severe accident conditions is crucial for effective severe accident management. Based on the Facility for Aerosol Behavior and Containment Spray (FABCS), an experimental study was conducted on polydisperse, multi-species submicron aerosol particles. The results showed that the minimum attenuation particle size for submicron aerosols ranged from 0.2 to 0.5 μm and decreased with higher spray flow rates. For multi-component aerosols, this size varied with the count median diameter. Increased spray droplet velocity and smaller droplet size raised Stokes numbers, enhancing inertial impaction. Higher gas-phase temperatures increased the aerosol removal rate due to thermophoresis. This study offers crucial data for predicting the minimum attenuation particle size of multicomponent submicron aerosols, aiding severe accident management.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105660"},"PeriodicalIF":3.3,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372580","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":"Validation of the PWR-core physics analysis software NECP-Bamboo based on NPP measurements","authors":"Yilin Liang,&nbsp;Yunzhao Li,&nbsp;Yuancheng Zhou,&nbsp;Yisong Li,&nbsp;Shilong Zhou,&nbsp;Hengrui Zhang,&nbsp;Weiguo Wang,&nbsp;Yuxiang Ou,&nbsp;Songzhe Wang,&nbsp;Junwei Qin,&nbsp;Liangzhi Cao,&nbsp;Hongchun Wu","doi":"10.1016/j.pnucene.2025.105634","DOIUrl":"10.1016/j.pnucene.2025.105634","url":null,"abstract":"<div><div>NECP-Bamboo is a PWR-core physics analysis software developed by the Nuclear Engineering Computational Physics (NECP) Laboratory at Xi'an Jiaotong University based on the improved two-step methodology. There are no engineering turning approximations so different PWR cores can be calculated using the same methodology setup. This paper calculated and summarized 64 cycles of 7 kinds of PWR cores. The fuel enrichments range from 1.8% to 4.45%, while burnable poisons contain borosilicate glass and gadolinium-doped fuels. The lattice structures in fuel assembly are either 17 × 17 or 15 × 15. Notably, the number of fuel assemblies in each core encompasses 121, 157, 177, or 193. Calculated parameters were compared with the corresponding Nuclear Power Plant (NPP) measurements, including critical boron concentration, temperature coefficient, rod cluster control assembly worth in the start-up tests, together with the critical boron concentration, and assembly radial relative power distributions in the power operation periods. All the statistical errors agree well with the corresponding acceptable safety limits.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105634"},"PeriodicalIF":3.3,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350199","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 and integration of a tool for physics-based shape and topology optimization in the MOOSE multiphysics simulation framework","authors":"Muhammad Ramzy Altahhan ,&nbsp;Nicholas Herring ,&nbsp;Sebastian Schunert ,&nbsp;Yousry Azmy","doi":"10.1016/j.pnucene.2025.105619","DOIUrl":"10.1016/j.pnucene.2025.105619","url":null,"abstract":"<div><div>We developed a C++ computational tool for physics-based shape and topology optimization and integrated it into the MOOSE multiphysics simulation framework. The tool implements combinatorial and discrete optimization algorithms, and includes performance enhancements like solution caching, tabu lists, and multi-run restarts. We demonstrate the tool’s flexibility with two applications that utilize different MOOSE physics modules. We implemented a Simulated Annealing search engine in our new tool. The first application is novel, adopting a two-dimensional Cartesian geometry representation of a pin-cell aiming for the optimal distribution of fuel and moderator material on a fixed mesh that maximizes neutron multiplication and coolant’s hydraulic diameter. Constraints were applied to the search procedure, and we explored their effect on the realized optimal shape, identifying a set that includes preliminary manufacturability constraints and that produces a Cartesian approximation of annular fuel pins, previously proposed by physical intuition. The second is a traditional PWR fuel shuffling application at the full-core scale aiming at minimizing peak power over the core. This capability was not available in MOOSE and is used to illustrate the flexibility of our new optimization capability to address other types of discrete optimization demands. In our test case, we obtained a 1250 pcm improvement in the multiplication factor and a reduced assembly power peaking of more than 30% relative to the initial unoptimized state comprising an IAEA-2D benchmark-based core. The loading patterns generated were consistent with established literature. This work enables multi-scale reactor design improvements, from the individual fuel pin level to the full core level. Future work will leverage MOOSE’s multiphysics capabilities to execute coupled-physics optimization exercises.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105619"},"PeriodicalIF":3.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of copper oxide nanoparticles on the thermal behavior of silica aerogel/paraffin as a phase change material in a cylindrical channel with molecular dynamics simulation","authors":"Jun Yang ,&nbsp;Ali B.M. Ali ,&nbsp;Younis Mohamed Atiah Al-zahy ,&nbsp;Narinderjit Singh Sawaran Singh ,&nbsp;Mohammed Al-Bahrani ,&nbsp;Tatyana Orlova ,&nbsp;Mojtaba Rahimi ,&nbsp;S. Salahshour ,&nbsp;S. Esmaeili","doi":"10.1016/j.pnucene.2025.105645","DOIUrl":"10.1016/j.pnucene.2025.105645","url":null,"abstract":"<div><div>The thermal conductivity of phase change materials was substantially enhanced by nanoparticles, improving the overall performance of thermal energy storage systems through more efficient heat transfer during the phase change process. This study investigates the effect of varying amounts of copper oxide nanoparticles on the thermal behavior of silica aerogel/paraffin as a phase change material in a cylindrical channel. LAMMPS and molecular dynamics simulations were employed to analyze this using a computer program. Results show that the atomic sample density and velocity reached 0.1393 Å³ and 0.0119 Å/fs, respectively, with the addition of 5% nanoparticles to the target structure. The atomic samples also reached a maximum temperature of 635 K when 5% of nanoparticles were added. The heat flux and thermal conductivity increased from 66.43 W/m² and 1.74 W/m·K to 71.25 W/m² and 1.82 W/m·K with a CuO-NP concentration increase of 3%. Adding nanoparticles enhanced thermal conduction, improving the overall interaction between the PCM and the nanoparticles. This led to better thermal contact and reduced thermal resistance at interfaces. However, adding more nanoparticles may lead to agglomeration, where the nanoparticles cluster together instead of remaining evenly dispersed. This can negatively affect thermal properties, as agglomerated particles create larger voids in the material, reducing the effective contact area for heat transfer. Using molecular dynamics simulations provided valuable insights into optimizing nanoparticle concentration for improved thermal performance in energy storage applications.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105645"},"PeriodicalIF":3.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143233881","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":"Temperature sensitivity of the equilibrium neutronics and accident analysis of the HTR-10","authors":"Annie Berens ,&nbsp;Friederike Bostelmann ,&nbsp;Nicholas R. Brown","doi":"10.1016/j.pnucene.2025.105643","DOIUrl":"10.1016/j.pnucene.2025.105643","url":null,"abstract":"<div><div>Pebble-Bed High-Temperature Gas-cooled Reactors (PB-HTGR) are moderated by the graphite in the fuel pebbles and the graphite reflector surrounding the pebble-bed. Because graphite is by far the most abundant material in PB-HTGRs and the primary moderator, accurate modeling of the graphite material, including density, impurities, and temperatures, is crucial for accurate computational modeling and simulation of these reactors. While main characteristics of the graphite components are often known, the local temperature is less well known and often averaged over all components. This work studies the impact of considering accurate temperature profiles in the graphite material on the generation of a small PB-HTGR model at the state of equilibrium operation and on short-term accident progression. The fuel compositions for the PB-HTGR were determined using a jump-in equilibrium modeling method, the Axial Radial Zone Equilibrium Modeling (AR-ZEM) method. In contrast to previous work, the AR-ZEM method was used considering thermal-hydraulic feedback from the MELCOR code to determine temperatures of the fuel pebbles and the surrounding graphite reflector. The consideration of an axial and radial temperature profile in the core and reflector, as opposed to uniform material temperatures, had an impact of almost 1,300 pcm on the equilibrium core eigenvalue and caused significant differences in the discharged plutonium fuel inventory with up to 4.9% and 11.0% for Pu-239 and Pu-242, respectively. To assess the impact on short-term accident progression, two Anticipated Transient Without SCRAM (ATWS) events, a Pressurized Loss of Forced Coolant (PLOFC) and a Control Rod Withdrawal (CRW) with loss of flow, were simulated with MELCOR. The use of temperature profiles in the equilibrium core models did not reveal a significant impact on the temperature, power, or reactivity responses during the transients. In conclusion, a need for consideration of accurate temperature profiles, in particular for the graphite reflector, was found for the generation of equilibrium PB-HTGRs core models using jump-in methods, but detailed temperature profiles may not be necessary when performing conservative transient analysis.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105643"},"PeriodicalIF":3.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349942","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":"Analyzing neutronic characteristics of fuel assemblies and their performance with increasing burnup for Canadian PT-SCWR","authors":"Shuvendu Shivam,&nbsp;Satya Sekhar Bhogilla,&nbsp;Goutam Dutta","doi":"10.1016/j.pnucene.2025.105638","DOIUrl":"10.1016/j.pnucene.2025.105638","url":null,"abstract":"<div><div>The Pressure-Tube Supercritical-Water-Cooled Reactor (PT-SCWR) is being explored by the Generation IV International Forum due to its potential to achieve greater thermal efficiency compared to existing nuclear reactor designs. With the DRAGON5 deterministic lattice code and the ENDF/B-VIII cross-section data library, computational simulations for comparing different fuel assembly design was performed to evaluate neutronic characteristics relevant to research in reactor physics, like the neutron multiplication factor and temperature coefficients of reactivity. Six different fuel assembly configuration with three distinct fuel ring bundle design were considered in the study with burn-up calculations up to 1000 Effective Full Power Days (EFPD). The study verified the reliability of the applied numerical simulation methodology by comparing main neutronic parameters with literature and benchmark data, confirming their good agreement. The values of infinite multiplication factor (<span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>i</mi><mi>n</mi><mi>f</mi></mrow></msub></math></span>) and various reactivity coefficients were determined and two ring fuel bundle showed a higher criticality period (<span><math><mrow><mo>≈</mo><mn>34</mn><mtext>%</mtext></mrow></math></span> more) than the three ring design. The fuel, moderator and coolant temperature sensitivity of reactivity was investigated and compared for different fuel burnup periods. The effect of fuel composition and different fuel enrichment on discharge burnup was also taken into consideration. Several types of models with different fuel composition was examined and their respective effective Instantaneous Critical Burnup (ICB) along with reactivity decrease rate was evaluated. Also, the novel work of comparing the performance of different central rod constituent and its consequence on the neutronic behavior of fuel assembly was assessed by varying the central rod to fuel pin, Zirconium Oxide (ZrO) rod and light water. By incorporating water in the central rod and adopting two-ring fuel bundles, PT-SCWR designs can effectively tackle various challenges. Two-ring fuel bundles has better performance than three or four-ring configurations, while radially cascaded fuel enrichment boosts fuel utilization and burnup. Additionally, using water as a central rod coolant, rather than ZrO or fuel rods, mitigates reactivity, yielding a desirable negative void reactivity. This comparative analysis underscores key considerations for enhancing PT-SCWR performance.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105638"},"PeriodicalIF":3.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143233875","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":"Research on design and optimization method for a supercritical CO2 centrifugal compressor for gas-cooled micro reactors","authors":"Daogang Lu ,&nbsp;Minglei Liu ,&nbsp;Xiaotian Wang ,&nbsp;Qiong Cao ,&nbsp;Yu Liu ,&nbsp;Jinjian Li","doi":"10.1016/j.pnucene.2025.105630","DOIUrl":"10.1016/j.pnucene.2025.105630","url":null,"abstract":"<div><div>The supercritical carbon dioxide(sCO₂) Brayton cycle shows significant advantages over the steam Rankine cycle due to its compact size, minimal space requirements, and high energy density. It has become a highly promising research direction in the field of fourth-generation nuclear reactors. The compressor, a core component of this cycle, plays a crucial role in ensuring system efficiency and stable operation. Among various typical compressors, the centrifugal compressor stands out as an excellent choice for the sCO₂ Brayton cycle due to its compact size, ease of manufacturing and installation, superior performance, and efficient operation. The conventional one-dimensional (1D) centrifugal compressor design does not accurately reflect the flow and compression process especially near the critical point, while the conventional three-dimensional (3D) design lacks boundary conditions and geometric parameter selection basis, therefore, this paper proposes an effective combination method of 1D and 3D design. First, this paper introduces the orthogonal test method to determine the primary parameters for the 1D design of sCO₂ centrifugal compressors, which shows an effective reduction in workload. Next, after validating the design method, the design and optimization of a 300 kW sCO₂ compressor in 3D has been carried out. Performance curves are obtained under different blade wrap angles and tip clearances. The optimal values of blade wrap angle and tip clearance of the compressor are identified using the sensitivity analysis. Finally, the performance of the optimized centrifugal compressor has been investigated through numerical simulation under several rotational speeds, inlet pressures, and inlet temperatures around the set operating conditions. This research holds significant implications for the design of sCO₂ centrifugal compressors in gas-cooled micro reactors.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"181 ","pages":"Article 105630"},"PeriodicalIF":3.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143233878","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":"Quantitative comparison of explainable artificial intelligence methods for nuclear power plant accident diagnosis models","authors":"Seung Geun Kim ,&nbsp;Seunghyoung Ryu ,&nbsp;Kyungho Jin ,&nbsp;Hyeonmin Kim","doi":"10.1016/j.pnucene.2025.105605","DOIUrl":"10.1016/j.pnucene.2025.105605","url":null,"abstract":"<div><div>The rapid advancement of artificial intelligence (AI) technology based on deep neural networks (DNNs) has spurred active development of DNN-based models in the nuclear domain. Due to the black-box nature of these models and the issue of low explainability, their practical application in safety-critical domains is hindered. To address this, numerous explainable AI (XAI) methods have been proposed. However, the selection of an appropriate XAI method is crucial as its performance significantly depends on various factors; nonetheless, comparative studies of XAI methods are limited within the nuclear domain. This study employs perturbation analysis for the quantitative comparison of XAI methods. A method for selecting an appropriate perturbing value is also proposed based on the concept of information entropy to yield reliable perturbation analysis results. For the experiment, a simple nuclear power plant (NPP) accident diagnosis model was developed to reflect the characteristics of the nuclear domain, and four XAI methods were applied for comparative analysis. The experimental results demonstrate that perturbation analysis and the proposed method are effective for quantitatively comparing the performance of XAI methods.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"180 ","pages":"Article 105605"},"PeriodicalIF":3.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of oxide and α-Zr(O) growth kinetics in the temperature range 1000–1500 °C during steam oxidation of Indian PHWR cladding","authors":"Tapan K. Sawarn ,&nbsp;Suparna Banerjee ,&nbsp;Saee Jagtap ,&nbsp;Alexander Rajath ,&nbsp;Raman Saini ,&nbsp;Sayandeep Kundu ,&nbsp;Sripooja Mishra ,&nbsp;P.P. Nanekar","doi":"10.1016/j.pnucene.2025.105632","DOIUrl":"10.1016/j.pnucene.2025.105632","url":null,"abstract":"<div><div>Isothermal steam oxidation of Indian pressurized heavy water reactors (IPHWRs) cladding (Zircaloy-4) has been studied in the temperature range of 1000–1500 °C. Growth kinetics of inherently brittle phases, oxide and oxygen stabilized α-Zr, developed during the high temperature steam oxidation were established. A ductile phase known as prior β-Zr, lying either underneath the α-Zr(O), in case of a single sided oxidation, or in between two layers of α-Zr(O) at the inner and the outer surface of the clad, governs the extent of embrittlement of the clad. Thickness of prior β-Zr is decided by the rate of growth of oxide and oxygen stabilized α-Zr. The kinetic rate constant K_p (cm²/sec) obeyed a parabolic rate equation. The Arrhenius expression of parabolic rate constants for oxide scale and α-Zr(O) layer growth compares well with those established by other investigators. An in-house oxidation model, OXYCON was evaluated against the experimental data of oxide and α-Zr(O) layer thickness. The model under-predicted the oxide layer thickness and over-predicted the α-Zr(O) layer thickness in its existing form. However the prediction of oxide, α-Zr (O) and total oxide+α-Zr(O) improved to a significant extent by using kinetic equations derived in the present study done on the indigenously fabricated Zircaloy-4 cladding. Hence, successively the prediction of the prior β-Zr layer thickness could also be done with further accuracy.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"180 ","pages":"Article 105632"},"PeriodicalIF":3.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140931","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":"Free outflow from the end of a horizontal circular pipe related to flow from the PWR cold leg to the downcomer","authors":"Akira Satou ,&nbsp;Takashi Hibiki ,&nbsp;Ryo Ikeda ,&nbsp;Yasuteru Sibamoto","doi":"10.1016/j.pnucene.2024.105593","DOIUrl":"10.1016/j.pnucene.2024.105593","url":null,"abstract":"<div><div>During a loss-of-coolant accident in a pressurized water reactor (PWR), there is a risk that pressurized thermal shock (PTS) may occur due to the rapid cooling of the downcomer wall caused by the emergency core cooling (ECC) water injected into the cold leg that flows into the downcomer. To predict the PTS, it is necessary to accurately predict the temperature of the ECC water, the collision of the water jet on the downcomer wall, the velocity, thickness, and the spread of the liquid film. Therefore, to help understand this flow phenomenon, we reviewed studies on free outflow from a circular pipe. In many previous studies, experimental findings on the flow regimes, transition conditions between flow regimes, characteristics of the flow shape have been obtained in a form that was almost consistent with each other. And, through theoretical analysis, it was also possible to predict the flow regime and flow surface shape to a certain extent quantitatively. In contrast, when considering the flow from the cold leg to the downcomer, it is necessary to deal with the flow field in a specific situation, such as the flow into a narrow gap rather than a free space, the existence of rounded corners at the outlet of the circular pipe, and the influence of steam flow flowing from the core to the cold leg. However, few previous studies consider these factors, so we summarized them as knowledge that needs to be accumulated in the future. In this review article, 30 references are included.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"180 ","pages":"Article 105593"},"PeriodicalIF":3.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}