Yu Zhao , Jianbang Wu , Xingliang Zhang , Wei Zhang , Bo Kuang , Pengfei Liu
{"title":"Experimental study of critical heat flux for upflowed water in narrow rectangular channels with different dimensions","authors":"Yu Zhao , Jianbang Wu , Xingliang Zhang , Wei Zhang , Bo Kuang , Pengfei Liu","doi":"10.1016/j.anucene.2025.111668","DOIUrl":"10.1016/j.anucene.2025.111668","url":null,"abstract":"<div><div>Flow boiling is an efficient heat transfer method; however, critical heat flux (CHF) leads to a sharp deterioration in thermal performance. As a key phenomenon in reactor systems, CHF has garnered significant research attention. To investigate the effects of geometric and thermodynamic parameters on CHF in rectangular narrow channels, an extensive experimental study was conducted across a broad parameter range, including pressures of 0.1–5.5 MPa, mass fluxes of 200–2000 kg/m<sup>2</sup>s, and inlet subcooling levels of 10–150 K. The experimental data were analyzed to elucidate the CHF triggering mechanism and the influence of various parameters. The results demonstrate that pressure, mass flux, inlet subcooling, channel length, and gap size significantly affect CHF. The Look-Up-Table method for CHF prediction was evaluated and found unsuitable for narrow rectangular channels. Comparisons with existing correlations revealed deviations in calculated results, likely due to the limited parameter ranges covered in prior studies. Based on the dimensionless correlation of heat flux and mass flux, a new CHF model was developed, incorporating channel dimension effects. The proposed correlation accurately captures the parametric trends and shows excellent agreement with the experimental data.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111668"},"PeriodicalIF":1.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313677","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":"Disposal of large quantities of plutonium and thorium utilization in VVER-1200 reactors using americium-stabilized MOX fuel","authors":"Ayhan Kara, Emil Mammadzada","doi":"10.1016/j.anucene.2025.111670","DOIUrl":"10.1016/j.anucene.2025.111670","url":null,"abstract":"<div><div>This study aims to investigate the feasibility of plutonium disposal and the usability of thorium in this process. The effects of adding Americium Dioxide (AmO<sub>2</sub>) to the Mixed Oxide (MOX) fuel content on the reactor performance have been analyzed in order to improve the sustainability of the fuel cycle of the Water-Water Energetic Reactor (VVER-1200), a Generation III pressurized water reactor. The research focuses on key parameters such as power distribution, neutron flux, infinite multiplication factor (<em>k<sub>inf</sub></em>), fuel depletion, and fission products. Findings based on simulations conducted using the Serpent and OpenMC Monte Carlo codes show that, despite some disadvantages, the addition of AmO<sub>2</sub> can enhance reactor performance, optimize fuel usage, and contribute to a more sustainable and efficient nuclear energy system.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111670"},"PeriodicalIF":1.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307002","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}
Wenchao Zhang , Qiaochen Du , Yue Wang , Benan Cai , Chao Liu , Lipeng Du , Weihua Cai
{"title":"Numerical simulation of flow and heat transfer characteristics of liquid lithium metal inside trapezoid shaped wire rod bundle channels","authors":"Wenchao Zhang , Qiaochen Du , Yue Wang , Benan Cai , Chao Liu , Lipeng Du , Weihua Cai","doi":"10.1016/j.anucene.2025.111667","DOIUrl":"10.1016/j.anucene.2025.111667","url":null,"abstract":"<div><div>The advancement of compact reactor technology, including the development of small and liquid metal reactors, has led to a surge of interest in the concept of wire-wound core arrangements for achieving enhanced compactness. The installation of trapezoid shaped wires permits the fuel rods to support themselves, facilitates the heat transfer through the channels, and allows for a compact configuration. However, the presence of wires introduces a degree of complexity to the flow and heat transfer process, prompting to investigate the thermo-hydraulic properties of fuel rod bundles with wires. This paper presents a numerical analysis model of a fuel rod bundle channel with trapezoid shaped wires in a hexagonal arrangement, with the objective of investigating the influence of trapezoid shaped wires on the flow and heat transfer characteristics. The results indicate the presence of transverse flow within the channel. The transverse velocity at the near-wall surface of the fuel rod is in alignment with the twisting direction of trapezoid shaped wires, whereas at the top of the wires, it is in opposition to this direction. The center rod and the corner rod exhibit low temperatures and high convective heat transfer coefficients at the trapezoidal winding wire. The transverse and axial velocities demonstrate periodic fluctuations with a period of approximately <em>H/4</em>, and a comparable pattern is evident in the fluctuations of the hot spot factor (<em>F<sub>HS</sub></em>) and Nusselt number (<em>Nu</em>). It is observed that frictional resistance coefficient (<em>f</em>) and convective heat transfer coefficient (<em>h</em>) of trapezoid shaped wire rod bundle channels are higher than those of classical round rod bundle channels. The pertinent research findings furnish a theoretical foundation for the utilization of this specific fuel rod in lithium-cooled fast reactors.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111667"},"PeriodicalIF":1.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307001","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}
Jiangchuan Song, Nan Gui, Tiezhong Lu, Xingtuan Yang, Shengyao Jiang
{"title":"Refining LBM accuracy and efficiency for neutron diffusion: Integrated strategies for model configuration and boundary treatment","authors":"Jiangchuan Song, Nan Gui, Tiezhong Lu, Xingtuan Yang, Shengyao Jiang","doi":"10.1016/j.anucene.2025.111638","DOIUrl":"10.1016/j.anucene.2025.111638","url":null,"abstract":"<div><div>A solution framework for neutron diffusion equations based on the higher-order lattice Boltzmann method (HLBM) was constructed, with detailed unit conversion procedures for this problem being systematically presented. The influences of relaxation time, discrete velocity models, and boundary condition treatment schemes on numerical performance were comprehensively examined. A nonlinear regulatory relationship between relaxation time and computational domain dimensions was investigated, while the effects of D2Q4, D2Q5, and D2Q9 discrete velocity models on solution accuracy and computational efficiency were comparatively analyzed. A novel boundary condition processing strategy was proposed and validated through comparison with analytical solutions. Research findings indicate that when the relaxation time is set within the range of 1.2 to 1.4, the system achieves the minimum computational error, and the proposed size-dependent dynamic optimization criterion for relaxation time has been proven to effectively reduce computational errors. Regarding discrete models, the D2Q4 model demonstrated superior comprehensive performance, exhibiting 53% and 83% reductions in mean relative errors compared with D2Q9 and D2Q5 models respectively, while achieving 42% faster convergence rates than both counterparts. The novel reflective boundary treatment scheme is demonstrated to exhibit a maximum relative error of 0.13%, while the zero boundary condition treatment scheme achieves a maximum relative error of 0.042%, with no significant increase in computational complexity. The reliability of both schemes is rigorously validated. These research outcomes provide quantitative parameter optimization criteria and innovative boundary treatment schemes for neutron diffusion simulations in nuclear reactors using HLBM, demonstrating significant engineering applicability.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111638"},"PeriodicalIF":1.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296992","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}
Yihu Wang , Ziang Guo , Tenglong Cong , Limin Liu , Hanyang Gu
{"title":"Investigation on coupling methods for heat transfer field between a reactor core and heat pipes","authors":"Yihu Wang , Ziang Guo , Tenglong Cong , Limin Liu , Hanyang Gu","doi":"10.1016/j.anucene.2025.111632","DOIUrl":"10.1016/j.anucene.2025.111632","url":null,"abstract":"<div><div>Heat pipe reactors are inherently safe, compact, and capable of providing a reliable energy supply for remote areas. Heat pipe reactors are often designed as solid-state reactors, enabling the analysis of the reactor through the integration of multiple coupled physical fields. This paper proposes a numerical method that uses the equivalent convective coefficient to solve the coupled heat transfer problem between the reactor core and heat pipes under steady-state conditions. This method effectively reduces the number of iterations and accounts for the uneven heat absorption effects of the heat pipes at the corner and side channels on the azimuthal direction. In this study, an open-source code <em>Multiphysics Object-Oriented Simulation Environment</em> (<em>MOOSE</em> for short) is used to implement the numerical method. The findings will support the coupling analysis procedure of a heat pipe reactor core and heat pipes.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111632"},"PeriodicalIF":1.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296987","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 hybrid parallel framework to solve convection-diffusion equation using finite element method with variational multiscale stabilization","authors":"Qiyue Lu , Ibrahim Jarrah , Rizwan-uddin","doi":"10.1016/j.anucene.2025.111608","DOIUrl":"10.1016/j.anucene.2025.111608","url":null,"abstract":"<div><div>Standard Galerkin method results in numerical instabilities when applied to the convection-dominated convection–diffusion equations. One approach to address this issue is the variational multiscale (VMS) stabilization technique. However, in the VMS in practice, geometry transformations of the corresponding operators are required, and the diffusion term in the stabilization part involves Christoffel symbols, which do not appear in the classical weak form of the <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>n</mi><mi>d</mi></mrow></msup></math></span>-order differential equations. Furthermore, the residual-driven stabilized finite element equation in the VMS method requires integration over multiple terms with different orders of polynomials. Therefore, intensive computational resources are needed to evaluate these terms, which makes the application of this method computationally expensive, especially when high-order elements are used. Optimum parallelization is therefore desirable. This work demonstrates the implementation and verification of the Galerkin approach stabilized using the VMS technique on a hybrid parallel framework with simultaneous use of different parallelization paradigms including shared memory (OpenMP), distributed memory (MPI), and GPGPUs. Load balancing on one heterogeneous computing platform is achieved by offloading the calculations to multiple GPUs, using shared memory parallelism for loops, and distributed memory for linear solvers. Verification of this implementation includes the convergence rate analysis using problems with manufactured solutions, and a benchmark case is solved to compare the convergence rate with other published work. The speed-up data are reported.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111608"},"PeriodicalIF":1.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296990","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}
J. Trainor , M.D. Eaton , J. Kópházi , S.G. Wilson , C. Latimer , L. Smith , D. Baker , I. Jordan
{"title":"NURBS-enhanced finite element spatial discretisation methods for the steady-state multigroup neutron diffusion equation","authors":"J. Trainor , M.D. Eaton , J. Kópházi , S.G. Wilson , C. Latimer , L. Smith , D. Baker , I. Jordan","doi":"10.1016/j.anucene.2025.111601","DOIUrl":"10.1016/j.anucene.2025.111601","url":null,"abstract":"<div><div>The NURBS-enhanced finite element method (NEFEM) is a recent innovation in spatial discretisation methods. The NEFEM combines the conventional FEM with computer-aided geometric design (CAGD) boundary representation (B-rep) approaches based upon Non-Uniform Rational B-spline (NURBS) geometrical representations of the computational domain. The aim of the NEFEM is to streamline the CAGD to computer-aided engineering (CAE) modelling and simulation (M&S) pipeline and provide improved geometrical representations of the underlying curvilinear geometry in nuclear reactor physics and reactor shielding simulations. This eliminates the requirement for local modifications to the underlying computational mesh to preserve the surface areas and volumes of curvilinear geometrical features within the computational domain. Such local mesh modifications are required, within conventional isoparametric Lagrangian FEM approaches, to preserve fissile mass and neutron leakage within curvilinear geometrical and computational domains.</div><div>This paper presents the application of the NEFEM to the multigroup neutron diffusion equation (NDE) for three nuclear reactor physics benchmark verification test cases. A further method of manufactured solution (MMS) benchmark verification test case is used to establish the order of convergence of the NEFEM compared to the FEM for both linear and quadratic elements. In addition, an analytical Wigner–Seitz pincell problem is used to further investigate the accuracy of the NEFEM. The results from these benchmark verification test cases demonstrate that the NEFEM yields improved numerical accuracy compared to the conventional FEM. This improved numerical accuracy is primarily achieved through the improved geometrical representation of curvilinear geometries. While the NURBS-enhancement of elements necessitates a small increase to the pre-processing time associated with the method, the increased accuracy of the NEFEM allows it to achieve competitive computational solution times compared to the standard Lagrangian FEM.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111601"},"PeriodicalIF":1.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290526","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}
Steven E. Skutnik, Friederike Bostelmann, Donny Hartanto, William A. Wieselquist
{"title":"New capabilities for rapid depletion analysis of pebble-bed reactors in SCALE","authors":"Steven E. Skutnik, Friederike Bostelmann, Donny Hartanto, William A. Wieselquist","doi":"10.1016/j.anucene.2025.111564","DOIUrl":"10.1016/j.anucene.2025.111564","url":null,"abstract":"<div><div>The SCALE Leap-In for Cores at Equilibrium (SLICE) method leverages capabilities available in the SCALE modeling and simulation suite to facilitate rapid estimation of equilibrium core inventories for flowing-pebble reactor systems in support of a variety of fuel cycle applications. New capabilities that compliment the SLICE method have been developed for the ORIGAMI interface to ORIGEN in SCALE to facilitate rapid depletion calculations for flowing-pebble systems. New features include a more generalized and flexible means of specifying interpolation dimensions, the ability to evaluate pebbles moving through user-defined “axial zones” in each of the pebble’s multiple passes through the core, and the treatment of differential velocities across radial channels (representing both pebble-to-pebble and wall-to-pebble friction effects). ORIGAMI thus provides an efficient user interface to define a pebble’s path and irradiation histories of its multiple passes through the core to calculate the pebble’s time-dependent inventories, which can be useful in various applications domains such as safeguards, criticality safety, and disposal analyses. The consistency of new ORIGAMI approach was verified against the solution obtained using the SLICE method with ORIGEN-ARP, showing excellent agreement.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111564"},"PeriodicalIF":1.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290959","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}
M.I. Sayyed , Chaitali V. More , F.I. Shaikh , M.R.I. Faruque , S. Abdullah , S. Yasmin , K.A. Mahmoud , Yasser Maghrbi
{"title":"Exploration of the effects of corporate lead, barium, and praseodymium oxides on mechanical, optical, structural, and gamma-ray shielding properties of borate-based glasses","authors":"M.I. Sayyed , Chaitali V. More , F.I. Shaikh , M.R.I. Faruque , S. Abdullah , S. Yasmin , K.A. Mahmoud , Yasser Maghrbi","doi":"10.1016/j.anucene.2025.111631","DOIUrl":"10.1016/j.anucene.2025.111631","url":null,"abstract":"<div><div>This work deals with the synthesis and characterization of a new borate-based glass series reinforced with various concentrations of PbO<sub>2</sub>, BaO, and Pr<sub>6</sub>O<sub>11</sub> according to the chemical formula of (7 + x)PbO<sub>2</sub>-(18 + y)BaO-12CaO-(63-x-y-z)B<sub>2</sub>O<sub>3</sub>-z Pr<sub>6</sub>O<sub>11</sub>; x = y = 0, 1, 2, and 3 mol%, while z = 0, 0.5, 1.0, and 1.5 mol%. The influence of the corporation of PbO<sub>2</sub>, BaO, and Pr<sub>6</sub>O<sub>11</sub> compounds on the structural, optical, mechanical, and radiation shielding characteristics was investigated. The evaluation shows that the raise in substitution of PbO<sub>2</sub> + BaO + Pr<sub>6</sub>O<sub>11</sub> for B<sub>2</sub>O<sub>3</sub> across the concentration of 25–32.5 mol% decreases the direct energy band gap between 3.08 and 2.82 eV. The absorption bands and corresponding IR active vibrational modes were identified for the synthesized glasses using FTIR spectrometry. The Makishima Makinzie model was applied to understand the behavior of mechanical modulus and mechanical properties for the glasses. The increase in PbO<sub>2</sub> + BaO + Pr<sub>6</sub>O<sub>11</sub> throughout a concentration range of 25–32.5 mol.% decreases slightly the microhardness of the prepared samples from 4.985 to4.736 GPa.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111631"},"PeriodicalIF":1.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296991","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}
Deping Du, Jincheng Wang, Xunjian Che, Jianchuang Sun, Weihua Cai
{"title":"A comparative study on the neutronic characteristics of the new four-petal and three-petal helix fuel assemblies","authors":"Deping Du, Jincheng Wang, Xunjian Che, Jianchuang Sun, Weihua Cai","doi":"10.1016/j.anucene.2025.111637","DOIUrl":"10.1016/j.anucene.2025.111637","url":null,"abstract":"<div><div>Petal-shaped helix fuel (PHF) enhances the reactor power and economic efficiency owing to its large heat transfer area, improved flow and heat transfer, and self-supporting structure. In this study, the neutronics characteristics of four petal-shaped fuel rods (FPF) and three petal-shaped fuel rods (TPF) are compared by analyzing the concave-convex ratio(also called the geometric factor for PHF, <em>R</em>/<em>r</em>), water-uranium ratio, and helix angle of the fuel rod. The results show that the difference in <em>R/r</em> values lead to different <em>k</em><sub>∞</sub> for FPF-FA and TPF-FA, and the <em>k</em><sub>∞</sub> of TPF-FA performs more excellently. For example, When <em>R/r</em> is equal to 2, the <em>k</em><sub>∞</sub> of TPF-FA is 1.13650, while that of FPF-FA is 1.12451. When the water-uranium ratio decreases from 2.3 to 1.5, the effective full power days of the FPF assembly increases from 420 to 750, and those of the TPF assembly increases from 480 to 810. At a helix angle of 720°, the maximum effective full power values for the FPF and TPF assemblies are 540d and 600d days, respectively. The non-uniformity coefficients of the FPF assembly are 0.02 % ∼ 1.80 % higher than those of TPF-FA. Finally, the FPF assembly exhibits better proliferation ability. Specifically, the resonance absorption of FPF-FA is always higher than that of TPF-FA, which improves the utilization of <sup>238</sup>U.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"223 ","pages":"Article 111637"},"PeriodicalIF":1.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290960","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}