Annals of Nuclear Energy最新文献

{"title":"Inversion of nuclear accident source terms combining Bayesian method with machine learning","authors":"Zhonghao Li ,&nbsp;Bo Cao ,&nbsp;Dingping Peng ,&nbsp;Qingyue You ,&nbsp;Xuewei Miao ,&nbsp;Zhouliang Chen","doi":"10.1016/j.anucene.2025.111418","DOIUrl":"10.1016/j.anucene.2025.111418","url":null,"abstract":"<div><div>Source term inversion plays a critical role in consequence assessment during nuclear accidents. This study investigates three Bayesian approaches for machine learning-based source term inversion, with datasets generated by the radioactive nuclide atmospheric dispersion program RADC. Firstly, a Bayesian neural network (BNN) was designed using Python to predict the release rate of I-131 during nuclear accidents. The BNN achieved a mean absolute percentage error (MAPE) of 7.92%, showing significantly higher accuracy and robustness compared to a backpropagation neural network (BPNN) with an identical structure and under the same accident scenarios. Secondly, both BNN and BPNN are further enhanced through Bayesian optimization, achieving a significantly improved MAPE values of 5.78% and 3.80% respectively. Furthermore, The Monte Carlo Dropout method was used to generate confidence intervals for the BPNN, offering an uncertainty analysis approach for conventional neural networks in source term inversion. However, its uncertainty analysis showed greater fluctuations compared to BNN.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111418"},"PeriodicalIF":1.9,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738349","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":"Novel geopolymer materials for fast and thermal neutron shielding","authors":"Jianxin Zhou ,&nbsp;Alexander Fields ,&nbsp;Shaffer Bauer ,&nbsp;Ali Ozer ,&nbsp;Waltraud M. Kriven ,&nbsp;Angela Di Fulvio","doi":"10.1016/j.anucene.2025.111388","DOIUrl":"10.1016/j.anucene.2025.111388","url":null,"abstract":"<div><div>In this work, we developed novel geopolymer (GP) composites for neutron shielding applications by dispersing up to 50 wt<span><math><mtext>%</mtext></math></span> polyethylene (PE) and boron carbide (B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C) powders into a potassium-based GP (KGP) matrix. We measured their attenuation coefficients to fast neutrons using a spontaneous fission ²⁵²Cf source and a fusion deuterium–tritium generator and to thermal neutrons using a moderated ²⁵²Cf source. The PE-based KGP were designed to reduce the neutron primary energy through neutron–hydrogen collisions, while ¹⁰B in B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C was exploited to capture and stop thermal neutrons. The fast-neutron shielding properties of 50 wt<span><math><mtext>%</mtext></math></span> PE-KGP were superior, with an attenuation coefficient to fission neutrons up to 30% higher than that of high-density concrete. The B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C-based KGP formulation with B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C at 25 wt<span><math><mtext>%</mtext></math></span> and 50 wt<span><math><mtext>%</mtext></math></span> outperforms commercial boron-loaded flexible materials by approximately 18% and 50%, respectively. In simulation, we combined KGP with PE and B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C dispersants. A prototypical material comprised of 50 wt<span><math><mtext>%</mtext></math></span> PE-KGP and 50 wt<span><math><mtext>%</mtext></math></span> B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C-KGP significantly outperformed barite in reducing the dose due to fission-based spectra, similar to those found at nuclear reactors. Additionally, KGP shows excellent adhesive properties, high-temperature resistance, and can be molded into any size or shape, as well as 3D or 4D printed. Therefore, PE and B<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>C-loaded KGP and associated manufacturing techniques can be effectively employed in nuclear power plants and other facilities that rely on intense neutron sources, significantly enhancing their safety and cost-effectiveness.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111388"},"PeriodicalIF":1.9,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724802","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":"Investigation of sodium compatibility of oxide ceramics for development of Advanced core Catcher for SFRs","authors":"Prabhat Kumar Shukla ,&nbsp;Hemanth Rao E ,&nbsp;E. Vetrivendan ,&nbsp;Vani Shankar ,&nbsp;Anish Kumar ,&nbsp;M. Muthuganesh ,&nbsp;Muthu Ambika ,&nbsp;Sanjay Kumar Das ,&nbsp;PK Chaurasia ,&nbsp;B.K. Sreedhar","doi":"10.1016/j.anucene.2025.111360","DOIUrl":"10.1016/j.anucene.2025.111360","url":null,"abstract":"<div><div>Core Catcher (CC) is a passive safety device, provided in nuclear reactors for safe retention of core debris resulting from a hypothetical core melt accident. For Sodium cooled Fast Reactors (SFR), in-vessel CC is preferred for containing radioactivity within the reactor vessel. Design of CC for new generation of SFRs consider whole core retention. To protect the CC against corium impingement and limiting the temperature of structural members within safe limit, a refractory sacrificial lining is being developed. Among several requirements, long term compatibility of sacrifical materials with liquid sodium under normal operation as well as accident condition are essential. In the present work, alumina and Yttria Stabilized Zirconia (YSZ) have been investigated as candidate materials. Test specimens of alumina and YSZ were exposed to liquid sodium at various temperatures from 400 °C to 950 °C for time durations up to 10000 h. The exposed specimens were investigated for microstructural damage and chemical interaction with sodium. YSZ specimens were found to be intact for temperatures up to 950 °C for 24 h, whereas alumina specimens revealed surface cracking and loss of strength above 850 °C. Though, no detectable chemical interaction with sodium was noticed for alumina and zirconia specimens at 400 °C for a long-term exposure, formation of sodium aluminate and sodium zirconate was observed at higher temperatures.</div><div>YSZ specimens exhibited insignificant degradation at high temperature sodium exposure, while alumina resulted in severe microstructural degradation. Important findings are outlined in the paper.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111360"},"PeriodicalIF":1.9,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724540","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 energy group structure optimization method for pressure water reactor plate-type fuel based on particle swarm algorithm","authors":"Jiannan Li,&nbsp;Ling Chen,&nbsp;Song Li,&nbsp;Yongfa Zhang,&nbsp;Jianli Hao","doi":"10.1016/j.anucene.2025.111422","DOIUrl":"10.1016/j.anucene.2025.111422","url":null,"abstract":"<div><div>The energy group structure significantly affects the accuracy and efficiency of cross-section and transport calculations. Plate-type reactors have significant differences in neutron dynamics compared to traditional rod reactors, which means that traditional energy group structures are not suitable for plate-type reactors. Therefore, it is necessary to explore new energy group structures to adapt to the complex structure of plate-type reactor cores. The paper proposes an optimization method suitable for the energy group structure of plate-type fuel based on the particle swarm algorithm. To ensure the universality of the obtained multi group structure in the plate-type fuel structure, the sensitivity of the plate elements parameters has been analyzed. Multiple examples are set up for optimization, with the average difference in <em>k</em>_∞ between multi-group and coarse-group transport calculations as the objective function, and the optimal energy group boundary position is sought by updating generation by generation. Based on the above method, the 15-group, 29-group, 37-group, and 45-group structures suitable for multi-group transport calculations of pressurized water reactor plate-type cores are optimized. Numerical verification shows that the group structure proposed in this paper has high computational accuracy for various operating conditions of pressurized water reactor plate-type cores, and significantly improves computational efficiency compared to the traditional 361-group structure.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111422"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724537","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":"Thermal hydraulic deformation analysis of fine 5 × 5 rod bundle fuel assembly based on multi-field coupling","authors":"Yunlong Wang,&nbsp;Rongchang Qiu,&nbsp;Guopeng Liang,&nbsp;Changjie Ying,&nbsp;Weidi Sun,&nbsp;Guan Guan,&nbsp;Chaoguang Jin","doi":"10.1016/j.anucene.2025.111421","DOIUrl":"10.1016/j.anucene.2025.111421","url":null,"abstract":"<div><div>This paper proposes a new multi physics field simulation method that integrates computational fluid dynamics, fluid structure coupling, and heat transfer theory for comprehensive analysis of complex reactions inside nuclear fuel cores. The methodology enables precise modeling of a 5 × 5 rod bundle fuel assembly, considering temperature-dependent material properties and non-uniform thermal convection. A bidirectional coupling analysis is conducted to explore the intricate interactions between thermal, fluid, and solid domains. The transient simulation, spanning 5 s, reveals a maximum displacement of 3.3 μm in fuel rods, with a cloud map highlighting temperature gradients and distinct deformations along radial and height directions. This research presents a feasible and efficient framework for importing and simulating three-dimensional fine models, yielding crucial displacement data pertinent to the thermal–hydraulic performance of fuel components. Its findings carry substantial engineering value for advancing nuclear reactor research, design optimization, and safe operation.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111421"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724539","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 study on a wire-wrapped fuel rod vibration induced by axial Pb-Bi coolant flow","authors":"Simian Qin ,&nbsp;Quanyao Ren ,&nbsp;Haidong Liu ,&nbsp;Lele Zheng ,&nbsp;Shanshan Bu ,&nbsp;Shan Huang ,&nbsp;Deqi Chen","doi":"10.1016/j.anucene.2025.111407","DOIUrl":"10.1016/j.anucene.2025.111407","url":null,"abstract":"<div><div>In this paper, the CFD analysis on the Pb-Bi axial flow around a wire-wrapped rod were performed and the vibrations of a wire-wrapped rod caused by the Pb-Bi axial flow were numerically studied. The effects of the pitches, flow rates and constraints on the vibration displacements and frequency were discussed. It was found that the transverse flow intensity increased twofold when the wire pitch was reduced from 400 mm to 200 mm. The augmentation of inlet flow rate from 1 m/s to 2 m/s resulted in an approximately fourfold amplification of the turbulent kinetic energy. The shear stress and pressure on the rod surface fluctuated significantly at the wire location. The force due to the wall shear stress was at least two orders of magnitude smaller than the pressure component. The vibration pattern of the fuel rod was consistent with the first-order vibration pattern and the main vibration frequency was close to the first-order natural frequency. The RMS of the fuel rod amplitude increased from 13.71 μm to 19.60 μm when the wire pitch decreased from 400 mm to 200 mm. When the inlet velocity increased from 1 m/s to 2 m/s, the RMS of the amplitude increased from 4.98 μm to 19.6 μm. When the both ends were restrained by completely fixed support, the vibration displacement at the center point decreased by 46 % compared to that in the case with circumferentially fixed in the upper end and completely fixed in the lower end. This study can provide the theoretical guide to the design of wire-wrapped fuel rods in the lead–bismuth cooled fast reactors.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111407"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724538","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":"Attenuation ability of tungsten and cadmium-reinforced polymeric materials as protective shields against gamma radiation and thermal neutrons","authors":"Dalal Abdullah Aloraini ,&nbsp;W.A. Abu‑raia ,&nbsp;Aly Saeed","doi":"10.1016/j.anucene.2025.111412","DOIUrl":"10.1016/j.anucene.2025.111412","url":null,"abstract":"<div><div>The pressing demand for efficient dual-function shields against gamma rays and neutrons has driven research. This study enhances polyvinyl alcohol (PVA) attenuation through the simultaneous addition of 10 &amp; 5, 20 &amp; 10, 30 &amp; 15, and 40 &amp; 20 wt% of WO₃ and CdO. The successful incorporation was confirmed by changes in density, FTIR, dynamic mechanical analysis, and optical absorption spectra. Adding 40 and 20 wt% of WO₃ and CdO increased the density by 4.5 times and raised the glass transition temperature from 39.762 °C to 74.423 °C. The mechanical properties showed significant improvement at higher concentrations of WO₃ and CdO. The shielding effectiveness of gamma rays and thermal neutrons revealed significant improvements: 407.4 %, 352.1 %, and 343.3 % for gamma rays at 661.64, 1173.23, and 1332.51 keV, respectively, and 1120.3 % for thermal neutrons. The results highlight the potential of PVA reinforced with WO₃ and CdO for nuclear shielding applications.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111412"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724803","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":"Implementation of dynamic Monte Carlo simulation using IMPC-NP for transient analysis of subcritical reactor driven by external neutron source","authors":"Peng Fang ,&nbsp;Yanling Zhu ,&nbsp;Feng Zhou ,&nbsp;Qiuying Liang ,&nbsp;Shijie Du ,&nbsp;Yongwei Yang ,&nbsp;Lei Yang","doi":"10.1016/j.anucene.2025.111415","DOIUrl":"10.1016/j.anucene.2025.111415","url":null,"abstract":"<div><div>In order to meet the requirements of neutron dynamics analysis for China’s initiating Accelerator Driven System (CiADS), we have implemented the calculation function of neutron kinetic parameters (<em>β</em>_eff and <em>Λ</em>_eff) and the Dynamic Monte Carlo transient analysis function in the Monte Carlo code IMPC-NP. Most importantly, based on this, we have implemented a dynamic transient analysis function with external neutron sources. This is the first simulation using dynamic Monte Carlo code with external neutron sources. On the basis of verifying the reliability of the code, this article simulated the external neutrons under subcritical conditions and obtained the flux variation law under specific conditions. This code can simulate the transient evolution of neutrons in ADS core under different external neutron souces strength and distributions in the future, providing important reference data for beam control of accelerators in ADS facility. This code tool has significant application significance.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111415"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724804","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":"Enhancement on optical properties and radiation shielding performance of new formulation zinc modified boro-tellurite glasses","authors":"Aliyu Sani ,&nbsp;Mohd Hafiz Mohd Zaid ,&nbsp;Khamirul Amin Matori ,&nbsp;Muhammad Khalis Abdul Karim ,&nbsp;Loh Zhi Wei","doi":"10.1016/j.anucene.2025.111411","DOIUrl":"10.1016/j.anucene.2025.111411","url":null,"abstract":"<div><div>The main goal of this research is to determine the fundamental characteristics of <em>x</em>ZnO − 30B₂O₃−(70-<em>x</em>)TeO₂ glass system that can be used as radiation shielding. Ultrasonic analysis and UV–Vis results show Urbach energy ranges from 1.071 to 0.737 S^-1, whereas the direct and indirect optical band gaps increase between 3.194 and 3.270 and 2.22 to 2.64 eV, respectively. The density of the glasses varies between 4.25 and 4.04 g/cm³. As the ZnO concentration increases, all elastic moduli decrease as well as microhardness from 5.63 to 3.92 GPa and Poisson’s ratio from 0.26 to 0.24 based on the results from ultrasonic measurement. The refractive index of a glass changes from 1.98 to 2.02, their molar volume decreases from 32.77 to 28.91 cm³/mol, and molar weight decreases from 132.61 to 116.96 g/mol, whereas oxygen molar volume ranges from 12.1 to 9.73, and the oxygen packing density changes from 2.3 to 2.1 mol/cm³. Electronegativity, Optical Polarizability, and Basicity ranging from 0.86 to 0.87, 2.73 to 2.71, and 1.27 to 1.26, respectively. All the radiation factors for the robust glass system were calculated using the Phy-X/PSD programming.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111411"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724805","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 boron concentration maneuvering control algorithm for reactivity management during transients in VVER-1000 nuclear power units","authors":"Ahmed E. Salman ,&nbsp;Hassan E. Gomaa","doi":"10.1016/j.anucene.2025.111381","DOIUrl":"10.1016/j.anucene.2025.111381","url":null,"abstract":"<div><div>Effective reactivity management is paramount for the safe and efficient operation of VVER-1000 reactors. A high-fidelity dynamic model is developed for boron control based on point kinetic equations, which capture the complex reactor kinetics, boron dynamics, and associated feedback systems governing the reactor’s behavior. The algorithm utilized a Proportional–Integral–Derivative controller optimized via Sequential Quadratic Programming (PID-SQP controller) to optimize boron maneuvering and compensate for external disturbances successfully. Step disturbances are applied to reactor inlet temperature at different boration/dilution rates to assess the algorithm’s resilience. The controller successfully regulated the power but exhibited different characteristics regarding overshoot, undershoot, smoothness of the change, and settling time. A statistical-based optimization analysis of the responses is conducted to determine the optimal levels for smooth and fast responses. The results exhibit enhanced stability, faster response times, and reduced boron overshoot transients. A dynamic optimization plot is constructed to figure out the boration/dilution rate yielding the highest composite desirability index.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"218 ","pages":"Article 111381"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715635","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}