Progress in Nuclear Energy最新文献_第5页

Numerical simulation of the flow flashing of carbon dioxide in a circular pipe 二氧化碳在圆管内流动闪蒸的数值模拟

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-31 DOI: 10.1016/j.pnucene.2025.106224

Wukun Zhu, Han Wang, Fanghao Chen, Jinghui Wu

The study of Loss of Coolant Accidents (LOCA) in supercritical carbon dioxide (S-CO₂) reactors constitutes a critical and challenging domain in nuclear safety analysis, with the investigation of flow flashing phenomena in pipelines being particularly pivotal. In this work, reactor pipelines were simplified, and a transient numerical simulation code for channel flow flashing was developed based on the homogeneous flow model, integrated with a suite of relevant correlations. Computational results from this code were validated against experimental data for water flow flashing, showing strong consistency with the measured values. Specifically, the maximum error in predicting flash onset (the point where vapor first forms) was approximately 5 %, thereby confirming the model accuracy. Utilizing the validated code, an in-depth analysis of the flow flashing process with CO₂ as the working fluid was conducted. For vertical pipes, higher inlet fluid temperature, lower outlet pressure, and lower inlet velocity were found to extend the length of the flashing two-phase region and increase the outlet void fraction. Furthermore, transient depressurization processes at the outlets of vertical pipes were numerically simulated to verify the code's transient analysis capabilities. For horizontal pipes, lower inlet pressure triggers adiabatic flashing, resulting in higher steam quality. Faster outlet depressurization initiates earlier flashing, enhances volume expansion, accelerates flow velocity, and elevates the peak mass flow rate. Overall, the computational results provide a solid theoretical foundation for LOCA analysis in S-CO₂ reactors.

超临界二氧化碳（S-CO2）反应堆冷却剂损失事故（LOCA）的研究是核安全分析中的一个关键和具有挑战性的领域，其中管道流动闪蒸现象的研究尤为关键。本文对反应器管道进行了简化，并基于均匀流动模型开发了通道闪蒸瞬态数值模拟程序。通过对水流闪蒸试验数据的验证，计算结果与实测值具有较强的一致性。具体来说，预测闪光开始（蒸汽首次形成的点）的最大误差约为5%，从而证实了模型的准确性。利用验证后的程序，对以CO2为工质的流动闪蒸过程进行了深入分析。对于垂直管道，较高的进口流体温度、较低的出口压力和较低的进口速度可以延长闪蒸两相区长度，增加出口空隙率。此外，还对垂直管道出口的瞬态降压过程进行了数值模拟，以验证该程序的瞬态分析能力。对于水平管道，较低的进口压力触发绝热闪蒸，导致更高的蒸汽质量。更快的出口减压启动了更早的闪蒸，增强了体积膨胀，加速了流速，提高了峰值质量流量。计算结果为S-CO2反应器的LOCA分析提供了坚实的理论基础。

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引用次数: 0

Study on mixed convection heat transfer characteristics of liquid lead-bismuth eutectic 液态铅铋共晶混合对流换热特性研究

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-30 DOI: 10.1016/j.pnucene.2025.106205

Jieming Hou , Bo Kuang , Shirui Li , Wenjun Hu

This study experimentally investigated the mixed convective heat transfer characteristics of liquid lead-bismuth eutectic (LBE) under buoyancy-aided flow condition. Over 30 steady-state tests were conducted on the Multi-Application LBE Thermal-Hydraulic test facility (MATH). By independently varying heating power, tube diameter and loop resistance, the combined influence of forced and natural convection was systematically explored. Dimensionless parameters (Gr, Re, Nu) reveal that buoyancy effects remain negligible when

\frac{Gr}{{Re}^{2}}

< 0.01, with Nu close to the existing forced convection correlation. As buoyancy increases, heat transfer decreases, and the flow enters the mixed-convection regime. An empirical correlation for the mixed-convective heat transfer of lead-bismuth eutectic with buoyancy correction was proposed based on theoretical derivation and experimental data. Deviations between predicted and experimental data remain within ±10 %. The results improve the accuracy of thermal-hydraulic simulations for LBE-cooled fast reactors under natural-circulation accident scenarios and provide a validated benchmark for further studies at higher heat fluxes and different flow orientations.

实验研究了浮力辅助流动条件下液态铅铋共晶（LBE）混合对流换热特性。在多用途LBE热液试验装置（MATH）上进行了30多次稳态试验。通过单独改变加热功率、管径和回路阻力，系统探索了强迫对流和自然对流的综合影响。无因次参数（Gr, Re, Nu）表明，当GrRe2 <； 0.01时，浮力的影响可以忽略不计，Nu接近现有的强迫对流相关。随着浮力的增加，换热减少，气流进入混合对流状态。基于理论推导和实验数据，提出了铅铋共晶混合对流换热的浮力修正经验关系式。预测数据与实验数据之间的偏差保持在±10%以内。研究结果提高了lbe冷却快堆在自然循环事故情景下的热工模拟精度，并为进一步研究高热流通量和不同流动方向下的热工模拟提供了验证基准。

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引用次数: 0

Research on the influence of gas-ingested flow on internal flow characteristics in reactor coolant pumps 注气流动对反应堆冷却剂泵内部流动特性影响的研究

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-29 DOI: 10.1016/j.pnucene.2025.106212

Dan Ni, Jinyu Yang, Xiang Yu, Hongchi Zhong, Sheng Lu, Yuquan Zhang, Bo Gao, Zhong Li, Ning Zhang

The reactor coolant pump is essential to nuclear power plant safety. During accidents like LOCA, gas entrainment leads to complex two-phase flow, degrading performance and challenging operational integrity. Current understanding of the associated flow mechanisms remains limited. To analyze the gas-liquid interaction mechanisms in an axial-flow reactor coolant pump under gas-ingested conditions, this study conducted theoretical investigations on the gas-liquid two-phase flow in nuclear reactor coolant pump. Flow characteristics under various air volume fractions (AVF), bubble diameters, and flow conditions were obtained using large-eddy simulation (LES) method with the Mixture multiphase model. Through experimental verification, it was found that the calculation method has an error within 2 % compared to actual results, confirming the accuracy of the model and numerical methods. The research systematically summarizes the performance variation patterns of the reactor coolant pump under two-phase flow conditions. The gas–liquid interaction mechanisms were elucidated through Q-criterion vortex identification, while the modified behavior of the spherical casing vortex under two-phase operation was analyzed. These findings contribute to nuclear engineering advancements by providing fundamental data for preventing severe two-phase flow conditions in reactor coolant pumps.

反应堆冷却剂泵对核电厂的安全至关重要。在LOCA等事故中，气体夹带会导致复杂的两相流动，降低性能并挑战作业完整性。目前对相关流动机制的理解仍然有限。为了分析轴流式反应堆冷却剂泵内气液相互作用机理，本研究对核反应堆冷却剂泵内气液两相流动进行了理论研究。采用混合多相模型，采用大涡模拟（LES）方法获得了不同空气体积分数（AVF）、不同气泡直径和不同流动条件下的流动特性。通过实验验证，发现计算方法与实际结果的误差在2%以内，证实了模型和数值方法的准确性。系统总结了两相流条件下反应堆冷却剂泵的性能变化规律。通过q准则涡识别阐明了气液相互作用机理，并分析了两相工况下球面机匣涡的修正行为。这些发现通过为防止反应堆冷却剂泵中严重的两相流动状况提供基础数据，有助于核工程的进步。

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引用次数: 0

Effective obsolescence management for improving safety of existing nuclear power plants 有效的报废管理，提高现有核电厂的安全性

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-28 DOI: 10.1016/j.pnucene.2025.106199

Kenta Murakami , Naoto Sekimura

This paper reviews diverse practices on safety improvements of existing nuclear fleets from the viewpoint of obsolescence management. First, the characteristics of obsolescence management in nuclear power were categorized and were compared with those in other industries. Next, for each category, the corresponding regulatory tools in multiple states were compared. Then, representative practices in the six technical areas, some of which are not traditionally recognized as obsolescence management, are presented and their characteristics are summarized. The parties involved in the obsolescence management extend beyond the typical “licensee versus regulator” structure, so that a mechanism to pay incentives to stakeholders for their efforts to improved safety is needed. The relationship between the obsolescence and quality management system is discussed, and the importance of “marketing of safety”, as a countermeasure of knowledge obsolescence, is discussed.

本文从陈旧管理的角度综述了现有核机组安全改进的各种实践。首先，对核电企业的报废管理特点进行了分类，并与其他行业进行了比较。接下来，对每个类别进行了多个州相应的监管工具的比较。然后，介绍了六个技术领域的代表性实践，其中一些传统上不被认为是过时管理，并总结了它们的特点。涉及报废管理的各方超出了典型的“被许可方与监管方”结构，因此需要一种机制来激励利益相关者为提高安全性所做的努力。论述了知识陈旧与质量管理体系的关系，探讨了“安全营销”作为知识陈旧对策的重要性。

引用次数: 0

Data-driven prediction of HTR-PM bottom reflector maximum temperature using recurrent neural networks 基于递归神经网络的HTR-PM底反射器最高温度数据驱动预测

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-28 DOI: 10.1016/j.pnucene.2025.106200

Ziwen Zhang , Zhongkai Sheng , Bing Xia , Ding She , Zuoyi Zhang

In pebble-bed high-temperature gas-cooled reactors (HTGRs), accurate monitoring and prediction of the maximum bottom reflector temperature are critical for safety margins and operations. To complement traditional physics-based simulation methods, we propose a data-driven time-series approach based on recurrent neural networks (RNNs) to predict the maximum temperature at the bottom reflector funnel location directly from operation histories. Using eight fixed operational variables as inputs and the measured maximum bottom reflector temperature as output, with additional detector-based features in optimal configurations, the RNN achieves root-mean-square errors (RMSE) of 13-21 °C when compared to measured temperature values. We report configurations with stationarized power steps and with additional detector signals, and demonstrate cross-module generalization capability.

在球床高温气冷堆（htgr）中，准确监测和预测最大底部反射器温度对安全边际和运行至关重要。为了补充传统的基于物理的模拟方法，我们提出了一种基于递归神经网络（RNNs）的数据驱动时间序列方法，直接从运行历史中预测底部反射器漏斗位置的最高温度。使用8个固定的操作变量作为输入，测量的最大底部反射器温度作为输出，在最佳配置中使用额外的基于探测器的特征，与测量的温度值相比，RNN的均方根误差（RMSE）为13-21°C。我们报告了具有平稳化功率步长和附加检测器信号的配置，并演示了跨模块泛化能力。

引用次数: 0

Research on the dynamic characteristics of disturbance waves in a 3×3 rod bundle channel 3×3棒束通道扰动波动态特性研究

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-27 DOI: 10.1016/j.pnucene.2025.106211

Guangyuan Jin, Jinghu Bai, Weilian Li, Hongye He, Yandong Hou

The dynamic characteristics of disturbance waves in a 3 × 3 rod bundle channel were investigated utilizing high-speed photography. The numerical simulations were performed to validate the experimental results, focusing on wave types, structural parameters and formation mechanisms. The disturbance wave structures were categorized into three types: small-scale waves, packet-like waves and band-like waves. The average liquid film thickness, wave height, and wave velocity exhibited a gradual increase with higher liquid superficial velocity. The effect of liquid velocity on wave frequency was primarily determined by the morphology of the disturbance waves. When liquid-phase velocity was held constant, the wave height decreased with increasing gas superficial velocity. Under identical flow conditions, the wave height gradually decreases from the corner rod to the edge rod and then to the center rod. The trends of wave velocity and wave frequency in relation to gas velocity and rod types were opposite to those of wave height. The velocity and pressure fields of the liquid phase responsible for generating the disturbance waves were analyzed. The generation of disturbance waves was driven by the high-speed turbulence of the gas phase and the wall reaction mechanism on the rod surface.

利用高速摄影技术研究了3 × 3棒束通道中扰动波的动态特性。通过数值模拟验证了实验结果，重点研究了波浪类型、结构参数和形成机制。扰动波结构可分为小尺度波、包状波和带状波三种。平均液膜厚度、波高和波速随液面流速的增大而逐渐增大。液体速度对波频的影响主要由扰动波的形态决定。当液相速度一定时，波高随气体表面速度的增加而减小。在相同的流动条件下，波高从角杆到边杆再到中心杆逐渐减小。波速和波频随气速和杆型的变化趋势与波高相反。分析了产生扰动波的液相速度场和压力场。干扰波的产生是由气相的高速湍流和棒表面的壁面反应机理驱动的。

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引用次数: 0

A novel fault diagnosis method for unknown faults in nuclear power plants considering domain adaptation and spatio-temporal feature fusion 基于域自适应和时空特征融合的核电厂未知故障诊断新方法

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-27 DOI: 10.1016/j.pnucene.2025.106209

Yushun Wang, Jingquan Liu

The fault diagnosis in nuclear power plants presents the significant challenge of an open-set scenario, where fault types encountered during the deployment phase were not known during the training phase. However, current mainstream methodologies predominantly operate based on a closed-set assumption. This approach may result in misdiagnosis or nondiagnosis of unknown faults as some form of known fault, thereby misleading operators and yielding consequential verification outcomes. In this paper, we introduce a novel approach that integrates CNN, LSTM, OpenMax, and EVT to enhance fault diagnosis performance in open-set scenarios. Fault diagnosis in nuclear power plants can primarily be divided into system-level and component-level assessments. To validate the efficacy of our proposed method across these domains, we performed fault diagnosis on both bearing assemblies and pressurized water reactor systems. Additionally, we explored the impact of various factors on diagnostic accuracy, including distance metrics, tail size, and openness. Our experiments demonstrate that the proposed model delivers high accuracy in open-set fault diagnosis at nuclear power stations. Typically, with an openness of less than 10%, an accuracy exceeding 90% can be achieved. Furthermore, among the three evaluated measurement methods, the cosine-based method shows the highest accuracy and stability.

核电厂的故障诊断面临着开放集场景的重大挑战，其中在部署阶段遇到的故障类型在训练阶段是未知的。然而，目前的主流方法主要是基于闭集假设。这种方法可能导致将未知故障误诊或误诊为某种形式的已知故障，从而误导操作人员并产生相应的验证结果。在本文中，我们引入了一种集成CNN、LSTM、OpenMax和EVT的新方法来提高开集场景下的故障诊断性能。核电厂的故障诊断主要分为系统级和部件级评估。为了验证我们提出的方法在这些领域的有效性，我们对轴承组件和压水堆系统进行了故障诊断。此外，我们探讨了各种因素对诊断准确性的影响，包括距离指标、尾部大小和开放性。实验结果表明，该模型在核电站开集故障诊断中具有较高的准确率。通常，在开放度小于10%的情况下，可以实现超过90%的精度。此外，在三种评估的测量方法中，基于余弦的方法具有最高的精度和稳定性。

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引用次数: 0

Numerical study on the optimization of petal-shaped fuel rod arrangement and heat transfer characteristics 花瓣形燃料棒布置优化及传热特性的数值研究

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-27 DOI: 10.1016/j.pnucene.2025.106210

Weihua Cai , Jian Zhang , Zequan Huang , Desheng Jin , Jianchuang Sun , Gongqing Wang , Wenchao Zhang

Fuel rods can enhance the heat exchange capacity of small reactors. In this paper, four new arrangements are designed to enhance heat transfer by changing the spiral direction of the ribs around petal-shaped fuel rods. Based on numerical simulations, the flow and heat transfer characteristics of petal-shaped fuel assemblies under different arrangements are compared, and the mechanism of the heat transfer enhanced by the configuration with the strongest comprehensive heat transfer performance is deduced. The study finds that the pressure drops of the four new arrangements are almost the same as those of the original arrangement. Based on the comprehensive performance evaluation index, it is determined that the fuel rod spacer arrangement with clockwise and counterclockwise twist in the diagonal direction has the best performance among the four arrangements. A further comparison of the heat transfer performance within each sub-channel of this staggered arrangement and the original arrangement reveals that the heat transfer coefficients within the four types of sub-channels are significantly enhanced. This is because the fuel rod spacer arrangement with clockwise and counterclockwise twist in the diagonal direction can significantly enhance the coolant flow on the leeward side of fuel rods, thereby reducing the thickness of velocity boundary layer and thermal boundary layer, strengthening the mixing of hot and cold fluids, and thus greatly improving the convective heat transfer performance in the leeward area. The relevant research results have laid a theoretical foundation for the arrangement scheme of the petal-shaped fuel rods within the reactor.

燃料棒可以提高小型反应堆的热交换能力。本文设计了四种新的布置方式，通过改变花瓣状燃料棒周围肋的螺旋方向来增强传热。在数值模拟的基础上，比较了花瓣形燃料组件在不同布置方式下的流动和传热特性，推导了综合传热性能最强的布置方式强化换热的机理。研究发现，四种新布置的压降与原布置的压降基本相同。根据综合性能评价指标，确定四种布置方式中，顺时针和逆时针方向扭转的燃料棒隔片布置方式性能最好。进一步比较了交错布置和原布置下各子通道内的换热性能，发现四种子通道内的换热系数都有显著提高。这是因为沿对角线方向顺时针和逆时针扭转的燃料棒间隔片布置可以显著增强燃料棒背风侧的冷却剂流动，从而减小速度边界层和热边界层的厚度，加强冷热流体的混合，从而大大提高背风区域的对流换热性能。相关研究成果为反应堆内花瓣状燃料棒的布置方案奠定了理论基础。

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引用次数: 0

Adaptive BP-PID control for steam generator level using hardware-in-the-loop simulation 基于硬件在环仿真的蒸汽发生器液位自适应BP-PID控制

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-26 DOI: 10.1016/j.pnucene.2025.106203

YuLong Wang, Zhejun Sun, Qi Zhang, Peiwei Sun, Xinyu Wei

The steam generator, an essential component of a pressurized water reactor nuclear power plant, has level parameters that directly influence the safety and stability of the nuclear power unit. The nonlinearity of the steam generator, coupled with the ‘false level’ issue, complicates its level control. Therefore, research on steam generator level control is considered to be of great significance. Traditional level control in steam generators employs a fixed-parameter Proportional-Integral-Derivative (PID) scheme, a widely used control strategy, which can struggle to adapt to changes in operating conditions and system characteristics. By integrating the adaptive learning capability of the Backpropagation (BP) neural network into the PID framework, a BP-PID control scheme is developed, where the BP network dynamically adjusts the PID parameters in real-time based on system feedback, enabling adaptive adjustment to varying operating conditions and enhancing control effectiveness. The proposed control algorithm was tested on a hardware-in-the-loop simulation platform. Results indicate that the BP-PID control significantly outperforms the original fixed-parameter PID control, demonstrating its potential for engineering implementation.

蒸汽发生器是压水堆核电站的重要组成部分，其液位参数直接影响核电机组的安全稳定运行。蒸汽发生器的非线性，加上“假液位”问题，使其液位控制复杂化。因此，对蒸汽发生器液位控制的研究具有重要的意义。传统的蒸汽发生器液位控制采用定参数比例积分导数（PID）控制策略，这是一种应用广泛的控制策略，难以适应运行条件和系统特性的变化。将BP神经网络的自适应学习能力融入到PID框架中，提出了BP-PID控制方案，BP网络根据系统反馈实时动态调整PID参数，实现了对不同工况的自适应调整，提高了控制效果。在硬件在环仿真平台上对所提出的控制算法进行了测试。结果表明，BP-PID控制明显优于原来的定参数PID控制，显示了其在工程实施中的潜力。

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引用次数: 0

Study of oxygen control model based on electrochemical oxygen pumping in liquid lead-bismuth alloys 基于电化学抽氧的铅铋液态合金氧控制模型研究

IF 3.2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy

Pub Date : 2025-12-25 DOI: 10.1016/j.pnucene.2025.106206

Zhenhua Sheng, Weihao Wu, Tengjun Geng, Shengfei Wang, Fang Liu, Huiping Zhu, Haicai Lyu, Wentao Guo, Zhangpeng Guo, Ruixian Liang, Fenglei Niu

To study the mass transfer characteristics of convection-enhanced oxygen transport in electrochemical oxygen pumps, a theoretical model of oxygen transport was developed based on reaction kinetics. Two-dimensional and three-dimensional mass transfer models were subsequently established using CFD software. The experimental validation showed that the model error was within 10 %. The oxygen transport process in the electrochemical oxygen pump can be broadly divided into two stages: the ion-transport-dominated mass transfer within the solid electrolyte and the diffusion-dominated mass transfer in the lead-bismuth. The oxygen enhancement rate and the minimum oxygen concentration during the oxygen reduction process were fitted to the Arrhenius equation, further confirming the accuracy of the theoretical model. Based on this validated model, flow fields were incorporated, and impeller stirring was employed to achieve convection-enhanced mass transfer, aligning closely with experimental conditions. The effects of impeller speed and temperature on oxygen transport in the lead-bismuth tank were evaluated using the multiphysics field model. The results show that convection enhancement can effectively enhance the mass transfer of electrochemical oxygen pumping in lead-bismuth without considering the limitations of solid electrolyte. By strengthening the convection effect in the lead-bismuth and the electrochemical oxygen pump, one can achieve a limited improvement in overall mass transfer efficiency.

为了研究电化学氧泵中对流强化氧输运的传质特性，建立了基于反应动力学的氧输运理论模型。随后利用CFD软件建立了二维和三维传质模型。实验验证表明，模型误差在10%以内。电化学氧泵中的氧传递过程大致可分为固体电解质中离子输运为主的传质过程和铅铋中扩散为主的传质过程两个阶段。将氧增强速率和氧还原过程中的最小氧浓度拟合到Arrhenius方程中，进一步证实了理论模型的准确性。在验证模型的基础上，加入流场，采用叶轮搅拌实现对流强化传质，与实验条件吻合较好。采用多物理场模型研究了叶轮转速和温度对铅铋槽内氧输运的影响。结果表明，对流增强可以在不考虑固体电解质限制的情况下有效地增强铅铋中电化学氧泵送的传质。通过加强铅铋和电化学氧泵中的对流效应，可以有限地提高整体传质效率。

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引用次数: 0