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Systematic experimental investigation on pressure build-up characteristics of water-jet injection into a molten LBE pool

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nuclear Science and Techniques 2025年第1期36卷 161-174页

作者： Hao-Ran Huang Zi-Jian Deng Song-Bai Cheng Jia-Yue Chen Sino‑French Institute of nuclear engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China College of nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China

In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the *** clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen *** obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle *** detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE ***,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure *** the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt ***,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam *** of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.

关键词： Lead-cooled fast reactor Steam generator tube rupture accident Pressure build-up characteristics Experimental study Pressure water-jet injection

A novel method for simultaneous measurement of^(222)Rn and^(220)Rn progeny concentrations measured by an alpha spectrometer

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nuclear Science and Techniques 2025年第1期36卷 127-139页

作者： Zhong-Kai Fan Jia-Le Sun Hao-Xuan Li Xiang-Ming Cai Hui Yang Shou-Kang Qiu Yan-Liang Tan Jian Shan school of nuclear Science and Technology University of South ChinaHengyang 421001China College of Physics and Electronic engineering Hengyang Normal UniversityHengyang 421008China

The accumulation of^(222)Rn and^(220)Rn progeny in poorly ventilated environments poses the risk of natural radiation exposure to the public.A previous study indicated that satisfactory results in determining the^(222)Rn and^(220)Rn progeny concentrations by measuring the total alpha counts at five time intervals within 560 min should be expected only in the case of high progeny concentrations in *** complete the measurement within a relatively short period and adapt it for simultaneous measurements at comparatively lower^(222)Rn and^(220)Rn progeny concentrations,a novel mathematical model was proposed based on the radioactive decay *** model employs a nonlinear fitting method to distinguish nuclides with overlapping spectra by utilizing the alpha particle counts of non-overlapping spectra within consecutive measurement cycles to obtain the concentrations of^(222)Rn and^(220)Rn progeny in *** verification experiments were conducted using an alpha *** experimental results demonstrate that the concentrations of^(222)Rn and^(220)Rn progeny calculated by the new method align more closely with the actual circumstances than those calculated by the total count method,and their relative uncertainties are all within±16%.Furthermore,the measurement time was reduced to 90 min,representing an acceleration of 84%.The improved capability of the new method in distinguishing alpha particles with similar energies emitted from ^(218)Po and^(212)Bi,both approximately 6 MeV,contributed to realizing more accurate *** proposed method has the potential advantage of measuring relatively low concentrations of^(222)Rn and^(220)Rn progeny in air more quickly via air filtration.

关键词： ^(222)Rn ^(220)Rn Progeny concentration Nonlinear fitting method Alpha spectrometer

Three-dimensional fracture of UO_(2)ceramic pellets by phase field modeling

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 165-176页

作者： Wei Xiong Xuan Ye Hongzhang Cheng Xiaoming Liu Institute of nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China school of engineering Science University of Chinese Academy of SciencesBeijing 100049China

Fracture is the primary failure type for the UO_(2)ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional(3D)UO_(2)ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

The optimal control theory——a scientific approach to fundamentally solving control problems

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Science China(Information Sciences) 2025年第1期68卷 389-391页

作者： Huanshui ZHANG school of Electrical and Automation engineering Shandong University of Science and Technology school of Control Science and engineering Shandong University

The maximum principle has bridged mathematical optimization to optimal control,ushering in significant developments and refinements in optimal control theory,notably during the 1960s with the advent of linear quadratic (LQ)control and linear quadratic estimation (LQE).This progression propelled optimal control theory into further advancements,encompassing stochastic control,robust/H-infinity control,model predictive control (MPC),networked control,and reinforcement learning *** control,established upon a rigorous mathematical foundation,extends static optimization theory to dynamic systems,exhibiting scientific essence,unity,and ***,since its inception,optimal control theory has served as an indispensable core role across all control-related domains,including communication-constrained control in networked systems,consensus control,cooperative control,and reinforcement learning control.

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Development and verification of the higher-order mode neutron flux calculation code HARMONY2.0

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nuclear Science and Techniques 2025年第1期36卷 207-225页

作者： Er-Pin Zhang Zi-Ning Ni Nian-Biao Deng Jin-Sen Xie Yong Liu Tao Yu school of nuclear Science and Technology University of South ChinaHengyang 421000China Key Laboratory of Advanced nuclear Energy Design and Safety Ministry of EducationHengyang 421000China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

Higher-order modes of the neutron diffusion/transport equation can be used to study the temporal behavior of nuclear reactors and can be applied in modal analysis, transient analysis, and online monitoring of the reactor core. Both the deterministic method and the Monte Carlo(MC) method can be used to solve the higher-order modes. However, MC method, compared to the deterministic method, faces challenges in terms of computational efficiency and α mode calculation stability, whereas the deterministic method encounters issues arising from homogenization-related geometric and energy spectra *** on the higher-order mode diffusion calculation code HARMONY, we developed a new higher-order mode calculation code, HARMONY2.0, which retains the functionality of computing λ and α higher-order modes from HARMONY1.0, but enhances the ability to treat complex geometries and arbitrary energy spectra using the MC-deterministic hybrid two-step strategy. In HARMONY2.0, the mesh homogenized multigroup constants were obtained using OpenMC in the first step,and higher-order modes were then calculated with the mesh homogenized core diffusion model using the implicitly restarted Arnoldi method(IRAM), which was also adopted in the HARMONY1.0 code. In addition, to improve the calculation efficiency, particularly in large higher-order modes, event-driven parallelization/domain decomposition methods are embedded in the HARMONY2.0 code to accelerate the inner iteration of λ∕α mode using OpenMP. Furthermore, the higher-order modes of complex geometric models, such as Hoogenboom and ATR reactors for λ mode and the MUSE-4 experiment facility for the prompt α mode, were computed using diffusion theory.

关键词： Neutron diffusion equation Higher-order modes Global homogenization Two-step method Domain

Porous framework materials for CO2 capture

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Journal of Energy Chemistry 2025年第2期101卷 278-297页

作者： Ziying Zhang Yu Dai Shiyi Zhang Liyi Chen Jian Gu Yong Wang Weiwei Sun school of Environmental and Chemical engineering Shanghai University

Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO2capture and *** organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other *** review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO2capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit ***,the main challenges associated with porous frameworks for CO2capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and *** review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.

关键词： Adsorption mechanism CO2 capture Modification Organic frameworks

On the interfacial behavior of a one-dimensional hexagonal piezoelectric quasicrystal film based on the beam theory

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Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 289-304页

作者： Wenkai ZHANG C.S.LU Minghao ZHAO Cuiying FAN Huayang DANG school of Mechanics and Safety engineering Zhengzhou University school of Civil and Mechanical engineering Curtin University school of Mechanical engineering Zhengzhou University

In this paper, the mechanical response of a one-dimensional (1D) hexagonal piezoelectric quasicrystal (PQC) thin film is analyzed under electric and temperature loads. Based on the Euler-Bernoulli beam theory, a theoretical model is proposed, resulting in coupled governing integral equations that account for interfacial normal and shear stresses. To numerically solve these integral equations, an expansion method using orthogonal Chebyshev polynomials is employed. The results provide insights into the interfacial stresses, axial force, as well as axial and vertical deformations of the PQC ***, fracture criteria, including stress intensity factors, mode angles, and the Jintegral, are evaluated. The solution is compared with the membrane theory, neglecting the normal stress and bending deformation. Finally, the effects of stiffness and aspect ratio on the PQC film are thoroughly discussed. This study serves as a valuable guide for controlling the mechanical response and conducting safety assessments of PQC film systems.

关键词： one-dimensional (1D) hexagonal piezoelectric quasicrystal (PQC) film beam theory electric and temperature loads Chebyshev polynomial interfacial behavior O343.1

A Multi-Condition Sequential Network Ensemble for Industrial Energy Storage Prediction Considering the Condition Switching Characteristics

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IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 369-380页

作者： Tianyu Wang Fan Zhou Yangjie Wu Jun Zhao Wei Wang IEEE the school of Control Science and engineering Dalian University of Technology the school of Information Science and engineering Dalian Polytechnic University

As a crucial storage and buffering apparatus for balancing the production and consumption of byproduct gases in industrial processes, accurate prediction of gas tank levels is essential for optimizing energy system scheduling. Considering that the continuous switching of the pressure and valve status(mechanism knowledge) would bring about multiple working conditions of the equipment, a multi-condition time sequential network ensembled method is proposed. In order to especially consider the time dependence of different conditions, a centralwise condition sequential network is developed, where the network branches are specially designed based on the condition switching sequences. A branch combination transfer learning strategy is developed to tackle the sample imbalance problem of different condition data. Since the condition or status data are real-time information that cannot be recognized during the prediction process, a pre-trained and ensemble learning approach is further proposed to fuse the outputs of the multi-condition networks and realize a transient-state involved prediction. The performance of the proposed method is validated on practical energy data coming from a domestic steel plant, comparing with the state-of-the-art algorithms. The results show that the proposed method can maintain a high prediction accuracy under different condition switching cases, which would provide effective guidance for the optimal scheduling of the industrial energy systems.

关键词： Ensemble learning industrial energy prediction multi-working condition structural deep network transfer learning

Pioneering radiation dosimetry and photothermal conversion in a photochromic and radiochromic thorium cluster

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Science China Chemistry 2025年

作者： Jingqi Ma Junpu Yang Huangjie Lu Tingrui Xu Huiliang Hou Raffaele Scalia Jian Lin school of nuclear Science and Technology Xi'an Jiaotong University Shanghai Institute of Applied Physics Chinese Academy of Sciences school of Materials engineering Jiangsu University of Technology school of Industrial and Information engineering Politecnico di Milano

Understanding the fundamental properties of actinide-based materials is pivotal in unlocking new solutions for challenges in nuclear waste management. In this work, we showcase a novel thorium cluster(Th-npc) that exhibits an extremely rare Th–N bond capping the square antiprismatic Th4+metal center. Remarkably, Th-npc exhibits both photochromic and radiochromic behaviors under UV and X-ray radiation, respectively, allowing for distinct, measurable colorimetric shifts that facilitate a redgreen-blue(RGB) radiation dosimetry method. The integration of Th-npc with a custom-built optoelectronic device enables onsite radiation dosimetry, offering the advantages of simple operation and rapid data acquisition. Additionally, this work pioneers the application of actinide materials in photothermal conversion, opening new avenues for the strategic utilization of thoriumbased compounds.

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