Progress in Nuclear Energy最新文献_第3页

Formation and evolution of radiation defects under low-temperature neutron irradiation 低温中子辐照下辐射缺陷的形成与演化

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-02-09 DOI: 10.1016/j.pnucene.2026.106289

A.V. Kozlov , N.V. Glushkova , K.A. Kozlov , K.M. Ladeyschikov , V.L. Panchenko , A.A. Zyryanova , E.V. Shabelnikov

The current study presents the way for consistent description of the processes of the radiation defects formation and evolution in conditions of low-temperature neutron irradiation. The topicality of the problem is due to the fact that exposure parameters such as temperature, rate of radiation damage, and damaging dose are not enough for description of the microstructure evolution. The main feature of the method consists in using the statistical model of defects migration. For the cross section descriptions of the interactions between neutrons (depending on their energies) and atoms the analytic expressions, fitting procedure is performed allowing calculations without expensive high-velocity electronic computing systems. The proposed approach was applied to describe the radiation defects evolution in chromium (as BCC structure pattern) exposed to low-temperature neutron irradiation in the reactor IVV-2M. It is shown that calculation results have a good match with experimental data regarding the number of vacancies accumulated in the sample during irradiation obtained using the dilatometer measurements. The developed approach is supposed to be uniform due to application for the description of defects formation and evolution in pure metals as well as in the alloys under irradiation in a wider temperature range in the reactors with various neutron spectra.

本研究为低温中子辐照条件下辐射缺陷形成和演化过程的一致性描述提供了途径。由于温度、辐射损伤速率和损伤剂量等暴露参数不足以描述微观结构的演变，因此该问题具有一定的时事性。该方法的主要特点是采用了缺陷迁移的统计模型。对于中子（取决于它们的能量）和原子之间相互作用的截面描述，执行解析表达式，拟合程序，允许不使用昂贵的高速电子计算系统进行计算。应用该方法描述了低温中子辐照下铬（BCC结构图）在IVV-2M反应堆中的辐射缺陷演化。用膨胀计测量得到的辐照过程中样品中累积空位数的计算结果与实验数据吻合较好。由于该方法适用于描述在较宽温度范围内辐照的纯金属和合金中的缺陷形成和演化，因而具有一致性。

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引用次数: 0

Study on hydrodynamic characteristics of symmetric two-droplet impact on film using lattice Boltzmann method 用晶格玻尔兹曼方法研究对称双液滴撞击薄膜的水动力特性

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-01-20 DOI: 10.1016/j.pnucene.2026.106269

Huifang Zhang, Jian Yu, Yapei Zhang, Shihao Wu, Wenxi Tian, Suizheng Qiu, Guanghui Su

Droplet impact on a liquid film is ubiquitous omnipresent and very fundamental in nature and industrial. For instance, in the spray cooling of the lower head of reactor pressure vessels, the method can enhance the safety margin of reactors. Extensive research has been carried out on the vertical impact of multiple droplets or single droplet on liquid films. However, the dynamical characteristics of multiple droplets impacting inclined liquid films remain insufficiently understood. Moreover, simulation approaches have predominantly concentrated on the Volume of Fluid (VOF) method. Therefore, this study attempts to conduct an in-depth numerical investigation of this phenomenon using the lattice Boltzmann method (LBM). A computational model was developed based on the Q3D27 and validated through benchmark cases involving single-droplet impacts on liquid films under both vertical and oblique conditions. The model accurately predicted key characteristics such as the outer diameter of the crown splash and the upstream crown radius. Based on the validated model, simulations of oblique impacts by dual droplets on a thin liquid film were conducted. The interfacial evolution was systematically analyzed, including the formation and development of crown splashes as well as the dynamics of intermediate thin-film jets. Furthermore, the Plateau-Rayleigh instability theory was employed to investigate the breakup mechanisms of liquid columns under varying impact angles and velocities. The fluid dynamic interactions between the two droplets under oblique impact conditions were also examined in detail, revealing complex flow behaviors relevant to multiphase flow dynamics.

液滴对液膜的影响在自然界和工业中是无处不在的，也是非常重要的。例如，在反应堆压力容器下封头喷雾冷却中，该方法可以提高反应堆的安全裕度。人们对多液滴或单液滴对液膜的垂直影响进行了广泛的研究。然而，多液滴撞击倾斜液膜的动力学特性仍未得到充分的了解。此外，模拟方法主要集中在流体体积法（VOF）上。因此，本研究试图利用晶格玻尔兹曼方法（LBM）对这一现象进行深入的数值研究。基于Q3D27建立了计算模型，并通过垂直和倾斜条件下单液滴撞击液膜的基准案例进行了验证。该模型准确地预测了关键特性，如冠飞溅外径和上游冠半径。在验证模型的基础上，对双液滴在薄膜上的斜碰撞进行了模拟。系统地分析了界面演化过程，包括冠状飞溅的形成和发展以及中间薄膜射流的动力学过程。利用高原-瑞利不稳定性理论研究了不同冲击角度和冲击速度下液柱破碎机理。本文还详细研究了两液滴在斜碰撞条件下的流体动力学相互作用，揭示了与多相流动力学相关的复杂流动行为。

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引用次数: 0

Experimental investigation of methyl iodide removal in venturi scrubber 文丘里洗涤器除甲基碘的实验研究

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-02-09 DOI: 10.1016/j.pnucene.2026.106268

Jawaria Ahad, Masroor Ahmad, Amjad Farooq, Khalid Waheed, Shafiq-ur Rehman, Naseem Irfan

Methyl iodide is a hazardous and volatile radioactive product that can be released during severe accidents in nuclear power plants, posing significant risk to human health and the environment. Therefore, efficient removal of methyl iodide is crucial for ensuring public safety and environmental protection. Due to its high volatility and hazardous nature, methyl iodide is difficult to handle, which has hindered extensive research into its removal using wet scrubbers. This study investigates the removal of methyl iodide using a venturi scrubber. Performance of a venturi scrubber is highly dependent on its operational parameters. So, influence of various parameters like liquid level height, gas flowrate, superficial velocity & gas holdup was studied. Results showed that the studied parameters had a positive impact on removal of methyl iodide. Additionally, the effect of different additives such as water, sodium hydroxide, sodium thiosulphate and Aliquat-336 was investigated. Best results were obtained from the combination of sodium hydroxide, sodium thiosulphate and Aliquat-336 and maximum removal efficiency of >98 % was obtained. This study also addresses the revolatilization of methyl iodide, considering its volatile nature by studying the effect of dose, pH and temperature. Results indicated that low dose, higher pH and temperatures up to 80

\overset{̊}{} C

can reduce revolatilization. Addition of Aliquat-336 was observed to be particularly effective in this regard. Furthermore, a mass transfer model for venturi scrubber was developed to evaluate the effect of afore-mentioned additives on methyl iodide removal. Good agreement was observed between experimental and simulation results. This research would be beneficial in understanding the influence of different parameters on removal of methyl iodide to achieve optimum removal efficiency in order to keep the environment safe and clean and for facilitating the development of nuclear energy.

甲基碘化物是一种危险的挥发性放射性物质，在核电站发生严重事故时可能释放出来，对人类健康和环境构成重大风险。因此，高效脱除碘化甲酯对保障公共安全和环境保护至关重要。由于其高挥发性和危险性，甲基碘很难处理，这阻碍了使用湿式洗涤器去除甲基碘的广泛研究。本文研究了文丘里洗涤器对甲基碘化物的去除。文丘里洗涤器的性能高度依赖于其操作参数。因此，研究了液面高度、气流量、表面流速、气含率等参数对其影响。结果表明，所研究的参数对甲基碘的去除有积极的影响。此外，还考察了水、氢氧化钠、硫代硫酸钠和Aliquat-336等不同添加剂的影响。氢氧化钠、硫代硫酸钠和Aliquat-336混合使用效果最好，去除率最高可达98%。考虑到甲基碘的挥发性，本研究还通过研究剂量、pH和温度的影响来研究甲基碘的旋化作用。结果表明，低剂量、高pH和高达80℃的温度均可减少旋转。在这方面，Aliquat-336的加入被认为特别有效。此外，还建立了文丘里洗涤器传质模型，评价了上述添加剂对甲基碘去除的影响。实验结果与仿真结果吻合较好。本研究有助于了解不同参数对甲基碘脱除的影响，以达到最佳的脱除效率，保持环境的安全和清洁，促进核能的发展。

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引用次数: 0

Heat conduction calculation of pebble-bed high temperature gas-cooled reactor based on nodal expansion method 基于节点展开法的球床高温气冷堆热传导计算

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-02-05 DOI: 10.1016/j.pnucene.2026.106277

Aolin Zhang, Dongyu Xu, Yongping Wang, Yuxuan Wu, Chuangye Zhou

The Pebble-Bed High-Temperature Gas-Cooled Reactor (PB-HTGR) features a core structure with porous media characteristics, leading to big differences from Pressurized Water Reactors (PWR) in terms of thermal-hydraulic calculation. For the solid heat conduction calculation of the whole core, mainstream codes, like THERMIX, mainly adopt the finite volume method. There is still room for further optimization of this method's computational efficiency. To address this issue, the Nodal Expansion Method (NEM), originally used for solving the neutron diffusion equation, is applied to the whole-core solid heat conduction calculation of PB-HTGR, aiming to improve the computational efficiency while maintaining the accuracy. A corresponding code TH-NEM is developed. Meanwhile, biquadratic polynomials are used for temperature reconstruction in the meshes. A series of steady-state and transient heat conduction problems are calculated, and the results are in good agreement with the reference. In addition, for the HTR-PM heat conduction problem, compared with the fine-mesh method, the proposed method achieves a speed-up ratio of 4. Finally, TH-NEM is used to simulate the depressurized loss of forced cooling (DLOFC) accident of HTR-PM. The calculated maximum fuel temperature is 1532 °C, which is 40 °C higher than that of the reference code but still within the limitation of 1620 °C.

球床高温气冷堆（PB-HTGR）的堆芯结构具有多孔介质特性，在热工水力计算上与压水堆（PWR）存在较大差异。对于整个堆芯的固体导热计算，主流规范如THERMIX主要采用有限体积法。该方法的计算效率仍有进一步优化的空间。为了解决这一问题，将原本用于求解中子扩散方程的节点展开法（NEM）应用于PB-HTGR全芯固体热传导计算，在保证计算精度的同时提高计算效率。开发了相应的TH-NEM代码。同时，采用双二次多项式进行网格温度重构。对一系列稳态和瞬态热传导问题进行了计算，结果与文献吻合较好。此外，对于HTR-PM热传导问题，与细网格方法相比，该方法的加速比为4。最后，利用TH-NEM模拟了HTR-PM强制冷却降压损失（DLOFC）事故。计算出的燃油最高温度为1532℃，比参考规范的最高温度高40℃，但仍在1620℃的限制范围内。

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引用次数: 0

A chattering-free fuzzy adaptive sliding mode controller based on a nonlinear two-point kinetics model for load-tracking of nuclear reactor 基于非线性两点动力学模型的核反应堆负荷跟踪无抖振模糊自适应滑模控制器

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-01-17 DOI: 10.1016/j.pnucene.2026.106254

Hailemichael Guadie Mengsitu , Xiuchun Luan , Hetao Sun , Fabiano Gibson Daud Thulu

In this study, a T-S type fuzzy logic controller-based chattering-free adaptive sliding mode controller is proposed to attain smooth and precise power-level control and disturbances rejection capability for the VVER-1000 reactor core. To accomplish the purpose, a nonlinear two-point kinetics model with three groups of delayed neutron precursors is developed. An adaptive T-S type fuzzy logic controller is considered to eliminate the chattering problem inherent in a conventional sliding mode controller, in which a continuous switching function replaces the discontinuous switching signum function. Stability analysis is guaranteed using the Lyapunov synthesis approach. To validate the designed controller, several simulations are conducted under various transient conditions. Furthermore, the designed controller is compared with a traditional sliding mode controller, a conventional PID controller with fixed parameters, and a fuzzy controller with standalone configurations. The results demonstrate that the proposed controller strategy exhibits effective load-tracking performance and adaptive disturbance rejection ability under load-following operations. It is adapted to different working conditions, effectively reduces overshoot and settling time, and produces a smooth control input deprived of the chattering problem in the actuator. It achieved an accurate estimation of most unmeasured states and removed the premise that all system states are quantifiable, which makes more sense from a practical standpoint, and it was able to estimate the majority of unmeasured states accurately. Furthermore, the system outputs, normalized axial offset, and axial xenon oscillation index remain within acceptable ranges based on a constant axial offset power-distribution strategy.

为了实现VVER-1000反应堆堆芯平滑精确的功率级控制和抗干扰能力，提出了一种基于T-S型模糊逻辑控制器的无抖振自适应滑模控制器。为此，建立了包含三组延迟中子前体的非线性两点动力学模型。为了消除传统滑模控制器固有的抖振问题，提出了一种自适应T-S型模糊控制器，用连续切换函数代替间断切换sgn函数。利用李亚普诺夫综合方法保证了稳定性分析。为了验证所设计的控制器，在各种暂态条件下进行了仿真。并将所设计的控制器与传统的滑模控制器、固定参数的传统PID控制器和独立配置的模糊控制器进行了比较。结果表明，所提出的控制器策略具有有效的负载跟踪性能和自适应抗干扰能力。它适应不同的工作条件，有效地减少了超调量和沉降时间，并产生了平滑的控制输入，消除了执行器中的抖振问题。它实现了对大多数不可测状态的准确估计，并且消除了系统所有状态都是可量化的前提，从实际的角度来看更有意义，并且能够准确地估计大多数不可测状态。此外，系统输出、归一化轴向偏置和轴向氙振荡指数保持在可接受的范围内，基于恒定的轴向偏置功率分配策略。

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引用次数: 0

Diagnosis of water hammer conditions in multi-pipeline system using data-driven and genetic algorithm approach 基于数据驱动和遗传算法的多管道系统水锤状态诊断

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-01-24 DOI: 10.1016/j.pnucene.2026.106274

Qingyin Zeng , Cheng Peng , Jiang Wu , Jian Deng

While existing experimental investigations and numerical simulations have preliminarily elucidated the multi-factor coupled mechanism governing Condensation-Induced-Water-Hammer (CIWH), the conventional threshold-based alarm approach predominantly relies on single-parameter criteria, e.g. typically pressure, which fails to effectively capture the early warning signs of CIWH. Concurrently, the genetic algorithm, recognized for its applicability in complex systems, remains relatively underutilized in the rapid identification of hazardous operating conditions, resulting in a technical gap where mechanistic understanding is disconnected from practical prevention and control requirements. This study investigates CIWH in the feedwater pipelines of the secondary circuit deaerator in nuclear power plants, where subcooled feedwater mixes with steam. A numerical simulation method based on the NUMAP code is developed to capture the underlying dynamics. Pilot study reveals that feedwater flow rate and pipe diameter jointly regulate the balance between inertial and frictional forces. This interaction shapes flow distribution and void fraction, which in turn influence the intensity of CIWH. Building upon this insight, a systematic analysis is conducted to quantify the effect of feedwater flow rate and pipe diameter on pressure variation rates, with peak values occurring at approximately 84.5 kg/s and 506 mm, respectively. To further identify hazardous operating conditions, a genetic algorithm (GA) is employed with different fitness functions. The results demonstrate that the relative change rate outperforms other metrics, whereas the mean absolute change and standard deviation show certain deviations, and the coefficient of variation is the least effective. This study confirms the effectiveness of the genetic algorithm in identifying hazardous operating conditions of CIWH under complex coupled scenarios and provides a feasible approach for predictive safety control and operational risk assessment in nuclear power plants.

虽然现有的实验研究和数值模拟已经初步阐明了冷凝诱发水锤（CIWH）的多因素耦合机理，但传统的基于阈值的报警方法主要依赖于单参数标准，如典型的压力，不能有效地捕捉到冷凝诱发水锤（CIWH）的预警信号。同时，遗传算法在复杂系统中的适用性得到认可，但在快速识别危险操作条件方面仍未得到充分利用，导致机械理解与实际预防和控制要求脱节的技术差距。本文研究了核电站二回路除氧器给水管道中过冷给水与蒸汽混合的CIWH。提出了一种基于NUMAP代码的数值模拟方法来捕捉其底层动态。初步研究表明，给水量和管径共同调节惯性力和摩擦力的平衡。这种相互作用决定了流动分布和空隙率，进而影响CIWH的强度。在此基础上，进行了系统分析，量化了给水流量和管径对压力变化率的影响，峰值分别约为84.5 kg/s和506 mm。为了进一步识别危险工况，采用了不同适应度函数的遗传算法（GA）。结果表明，相对变化率优于其他指标，而平均绝对变化和标准差存在一定的偏差，变异系数效果最差。本研究证实了遗传算法在复杂耦合情景下识别CIWH危险工况的有效性，为核电厂安全预测控制和运行风险评估提供了一种可行的方法。

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引用次数: 0

RELAP5-3D simulation of natural circulation start-up and station blackout benchmark for a NuScale-like iPWR 类似于nuscale的iPWR自然循环启动和站点停电基准的RELAP5-3D模拟

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-01-21 DOI: 10.1016/j.pnucene.2026.106265

Vincenzo Zingales , Francesco D'Auria , Yassin A. Hassan

This paper discusses the key features of integral Pressurized Water Reactors (iPWRs) including Helical Coil Steam Generators (HCSGs) and associated correlations. The objective is to highlight design challenges and system level modeling strategies.

A RELAP5-3D ver. 4.4.2 nodalization of a NuScale-like iPWR was created based on publicly available literature and, where necessary, design assumptions. The model was qualified under steady-state conditions against the NuScale Final Safety Analysis Report approved as part of the Design Certification Application (DCA) in 2020.

Because HCSGs are prone to instabilities, a start-up procedure was simulated to test the model response across a range of operating parameters. Primary flow and temperature results have been found to be consistent with DCA data at reduced power. However, at power levels below 60%, Type-II Density Wave Oscillations (DWOs) occurred in the HCSGs tubes. Analysis of subcooling and phase change numbers informed of potential mitigation strategies; however, stable performance at low power could not be obtained together with steam superheat and constant primary average temperature.

The main outcome of the present paper is the presentation of a collaborative benchmark internal to the Texas A&M University in which a station blackout scenario for a NuScale-like iPWR was simulated. Results obtained from RELAP5-3D were compared with those from TRACE, the NuScale Simulator, and DCA data, demonstrating strong qualitative agreement but highlighting quantitative discrepancies primarily due to geometric and correlation differences among the different models. RELAP5-3D simulations have specifically highlighted the occurrence of Type-I DWO if the ECCS is not timely activated.

本文讨论了包括螺旋盘管蒸汽发生器（hcsg）在内的整体式压水堆（iPWRs）及其相关特性。目标是强调设计挑战和系统级建模策略。RELAP5-3D版本。4.4.2基于公开可用的文献和必要时的设计假设，创建了类似于nuscale的iPWR的nodalization。该模型在稳态条件下符合NuScale最终安全分析报告，该报告是2020年设计认证申请（DCA）的一部分。由于hcsg容易不稳定，因此模拟了启动过程，以测试模型在一系列操作参数下的响应。一次流量和温度的结果已经发现与DCA数据在降低功率一致。然而，当功率低于60%时，hcsg管中出现了ii型密度波振荡（dwo）。了解潜在缓解战略的过冷和相变数分析；然而，在蒸汽过热度和一次平均温度不变的情况下，低功率下无法获得稳定的性能。本论文的主要成果是介绍了德克萨斯农工大学内部的协作基准，其中模拟了nuscal类iPWR的站点停电场景。从RELAP5-3D获得的结果与TRACE、NuScale Simulator和DCA数据进行了比较，结果表明定性一致，但突出了定量差异，主要是由于不同模型之间的几何和相关性差异。RELAP5-3D模拟特别强调了如果ECCS没有及时激活，就会发生i型DWO。

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引用次数: 0

Two-group interfacial area concentration model for downward dispersed two-phase flows 向下分散两相流的两组界面面积浓度模型

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-02-02 DOI: 10.1016/j.pnucene.2026.106271

Shaoting Jia, Takashi Hibiki

The two-fluid model is widely employed in thermal-hydraulic simulations of gas-liquid two-phase flows. Its predictive capability is strongly dependent on the accurate estimation of the interfacial area concentration (IAC), a key parameter governing the transfer of mass, momentum, and energy across the interphase. In dispersed flows, bubbles vary widely in size and morphology, which significantly influence their dynamics and contributions to IAC. Those variations necessitate a two-group classification: Group 1 (G1) for spherical and distorted bubbles, and Group 2 (G2) for cap, slug, and churn-turbulent bubbles. This study evaluated the predictive performance of several existing two-group IAC models, including IAC models implemented in RELAP5 and TRACE codes, as well as Song and Hibiki's IAC model, using compiled experimental data from vertically downward two-phase flows. The results showed that none of these models could predict the IAC with sufficient accuracy. To address this issue, the contribution of G1 bubbles to the total IAC was analyzed to investigate the flow behaviors for downward two-phase flows. Then, a two-group drift-flux correlation specifically developed for downward flows was introduced to predict the void fractions of G1 and G2 bubbles. Then, a new two-group Sauter mean diameter (SMD) model was formulated by considering the interfacial geometry effect and flow orientation. By integrating the drift-flux correlation and SMD model, an advanced two-group IAC model was proposed for downward two-phase flows. The proposed model demonstrated significantly improved predictive performance for downward dispersed flows, achieving mean absolute relative errors of 31.0 %, 26.7 %, and 27.9 % for G1, G2, and total IACs, respectively.

双流体模型广泛应用于气液两相流的热水力模拟。它的预测能力很大程度上依赖于界面面积浓度（IAC）的准确估计，而界面面积浓度是控制界面间质、动量和能量传递的关键参数。在分散流动中，气泡的大小和形态变化很大，这显著影响了它们的动力学和对IAC的贡献。这些变化需要两组分类：1组（G1）用于球形和扭曲气泡，2组（G2）用于帽状、段塞状和搅拌湍流气泡。本研究评估了几种现有的两组IAC模型的预测性能，包括在RELAP5和TRACE代码中实现的IAC模型，以及Song和Hibiki的IAC模型，使用编译的垂直向下两相流的实验数据。结果表明，这些模型都不能足够准确地预测IAC。为了解决这一问题，分析了G1气泡对总IAC的贡献，研究了向下两相流的流动行为。然后，引入专门针对向下流动开发的两组漂移通量相关性来预测G1和G2气泡的空隙分数。然后，考虑界面几何效应和流动方向，建立了新的两组Sauter平均直径（SMD）模型。将漂移通量相关模型与SMD模型相结合，提出了一种先进的下向两相流双组IAC模型。该模型对向下分散流动的预测性能有显著提高，G1、G2和总IACs的平均绝对相对误差分别为31.0%、26.7%和27.9%。

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引用次数: 0

Analysis of key nuclides in Xe irradiated by neutrons and their chemical behavior 中子辐照Xe中关键核素的分析及其化学行为

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-02-04 DOI: 10.1016/j.pnucene.2026.106291

Jia Tang , Yin Hu , Yi Xia , Jixue Sui , Jiajia Yang , Yunming Chen , Xiaogen Xiong , Yi Wang , Qi Cao

He-Xe binary mixture is a leading candidate for the fourth-generation gas-cooled reactor coolants. this study utilized MJTR to conduct in-pile irradiation experiments on quartz target components filled with Xe gas. The cumulative neutron fluence exceeded 1.0E16 n/cm². And a qualitative to semi-quantitative relationship between Xe impurities yield and neutron fluence was established. Based on the experimental results, the radioactivity derived from neutron irradiation of Xe in specific reactor system was estimated. The chemistry and deposition processes of these impurities was predicted. The results show that CsI and Cs₂Te are thermodynamically formable. Once formed, they are in solid state and unlikely to spontaneously decompose into atoms or ions. At temperatures below 1300–1400 K and 1100–1200 K, CsI and Cs₂Te may spontaneously undergo polymerization reactions to form dimers, which further crystallize, leading to the formation of macroscopic crystals. The main impurity Te would react with Inconel 617, a promising structure material, to form NiTe_0.69. This study deepens the understanding of the physical and chemical behavior of Xe under neutron irradiation and provides valuable guidance for the design and operational strategies of He-Xe coolant-based gas-cooled reactor systems.

氦-氙二元混合物是第四代气冷反应堆冷却剂的主要候选材料。本研究利用MJTR对充满Xe气体的石英靶件进行桩内辐照实验。中子累积通量超过1.0E16 n/cm2。并建立了Xe杂质产率与中子通量的定性-半定量关系。根据实验结果，估计了Xe在特定反应堆体系中中子辐照产生的放射性。预测了这些杂质的化学性质和沉积过程。结果表明，CsI和Cs2Te是可热成形的。一旦形成，它们就处于固态，不太可能自发地分解成原子或离子。在温度低于1300-1400 K和1100-1200 K时，CsI和Cs2Te可以自发地发生聚合反应，形成二聚体，二聚体进一步结晶，形成宏观晶体。主要杂质Te会与一种很有前途的结构材料Inconel 617反应生成NiTe0.69。该研究加深了对氙在中子辐照下的物理和化学行为的理解，为基于He-Xe冷却剂的气冷堆系统的设计和运行策略提供了有价值的指导。

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引用次数: 0

Prediction of post-dryout heat transfer based on physics-embedded machine learning with Bayesian optimization algorithm 基于嵌入物理的机器学习与贝叶斯优化算法的干燥后传热预测

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

Progress in Nuclear Energy

Pub Date : 2026-04-01 Epub Date: 2026-01-24 DOI: 10.1016/j.pnucene.2026.106263

Meiqi Song , Zuokai Chen , Jianhua Xia , Haozhe Li , Wei Xu , Xiaojing Liu

In nuclear power system, encountering the post-dryout heat transfer region can lead to severe heat transfer deterioration. Therefore, it is of great importance to give accurate prediction to post-dryout heat transfer. This study developed a new Physics-Embedded Machine Learning (PEML) framework to predict post-dryout heat transfer, addressing the limitations of traditional "black box" models by integrating physical constraints. Thirteen independent dimensionless parameters (e.g.,

R e_{TP}

,

\Pr_{w}

), i.e., input features, and Nusselt number

N u_{c}

are derived to present the physical heat transfer mechanism. The

N u_{c}

is embedded into the loss function in proportionality or subtractive relationship, i.e., PEML(Nu_exp/Nu_c) and PEML(Nu_exp-Nu_c). The prediction capability of PEML models are better than traditional correlations. The PEML(Nu_exp/Nu_c) model achieves the best prediction capability with the mean error of 0.0005 and RMS error of 0.007 on the testing dataset from Becker's PDO experiments. It is indicated that increasing the number of input features generally improved model performance, especially the generalizability. The PEML framework successfully embeds heat transfer physics, bridging data-driven models and physical insights, offering a robust prediction tool for heat transfer.

在核电系统中，遇到干后换热区会导致严重的换热恶化。因此，对干燥后传热进行准确预测具有重要意义。本研究开发了一种新的物理嵌入式机器学习（PEML）框架来预测干燥后的传热，通过集成物理约束来解决传统“黑箱”模型的局限性。导出了13个独立的无量纲参数（如ReTP， Prw），即输入特征和努塞尔数Nuc来表示物理传热机理。Nuc按比例或相减关系嵌入到损失函数中，即PEML（Nuexp/Nuc）和PEML（Nuexp-Nuc）。PEML模型的预测能力优于传统的相关模型。在Becker的PDO实验数据集上，PEML（Nuexp/Nuc）模型的预测能力最好，平均误差为0.0005，均方根误差为0.007。结果表明，增加输入特征的数量通常会提高模型的性能，尤其是泛化能力。PEML框架成功嵌入了传热物理，桥接了数据驱动模型和物理见解，为传热提供了强大的预测工具。

{"title":"Prediction of post-dryout heat transfer based on physics-embedded machine learning with Bayesian optimization algorithm","authors":"Meiqi Song , Zuokai Chen , Jianhua Xia , Haozhe Li , Wei Xu , Xiaojing Liu","doi":"10.1016/j.pnucene.2026.106263","DOIUrl":"10.1016/j.pnucene.2026.106263","url":null,"abstract":"<div><div>In nuclear power system, encountering the post-dryout heat transfer region can lead to severe heat transfer deterioration. Therefore, it is of great importance to give accurate prediction to post-dryout heat transfer. This study developed a new Physics-Embedded Machine Learning (PEML) framework to predict post-dryout heat transfer, addressing the limitations of traditional \"black box\" models by integrating physical constraints. Thirteen independent dimensionless parameters (e.g., <span><math><mrow><mi>R</mi><msub><mi>e</mi><mtext>TP</mtext></msub></mrow></math></span>, <span><math><mrow><msub><mi>Pr</mi><mi>w</mi></msub></mrow></math></span>), i.e., input features, and Nusselt number <span><math><mrow><mi>N</mi><msub><mi>u</mi><mi>c</mi></msub></mrow></math></span> are derived to present the physical heat transfer mechanism. The <span><math><mrow><mi>N</mi><msub><mi>u</mi><mi>c</mi></msub></mrow></math></span> is embedded into the loss function in proportionality or subtractive relationship, i.e., PEML(<em>Nu</em><sub>exp</sub>/<em>Nu</em><sub>c</sub>) and PEML(<em>Nu</em><sub>exp</sub>-<em>Nu</em><sub>c</sub>). The prediction capability of PEML models are better than traditional correlations. The PEML(<em>Nu</em><sub>exp</sub>/<em>Nu</em><sub>c</sub>) model achieves the best prediction capability with the mean error of 0.0005 and RMS error of 0.007 on the testing dataset from Becker's PDO experiments. It is indicated that increasing the number of input features generally improved model performance, especially the generalizability. The PEML framework successfully embeds heat transfer physics, bridging data-driven models and physical insights, offering a robust prediction tool for heat transfer.</div></div>","PeriodicalId":20617,"journal":{"name":"Progress in Nuclear Energy","volume":"194 ","pages":"Article 106263"},"PeriodicalIF":3.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039078","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}

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