CFD simulation of interassembly bypass flow in Sodium Fast Reactors

IF 1.9 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Nuclear Engineering and Design Pub Date : 2025-05-06 DOI:10.1016/j.nucengdes.2025.114044

A.J. Novak , C. Bourdot Dutra , D. Shaver , E. Merzari

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引用次数: 0

Abstract

Interassembly flow in Sodium Fast Reactors (SFRs) represents a bypass flow path exterior to the fuel assembly ducts. Heat transferred across this thin gap is an important component of core radial expansion, where the coupling between thermal-fluids, neutronics, and solid mechanics results in time-dependent duct bowing. These geometry changes can constitute a significant portion of the total reactivity response in transients, but are difficult to model in high-fidelity. Interassembly flow is also an important heat transfer mode during natural convection cooling. To improve our understanding of interassembly flow, this paper provides NekRS Reynolds Averaged Navier–Stokes (RANS) and Large Eddy Simulations (LES) of the interassembly flow in a 19-bundle fast reactor core. Time-averaged LES compares reasonably well with a

k

τ

RANS model, though RANS is not able to capture a crossflow which occurs at a large change in flow area between the duct–duct gaps and the open peripheral region. We predict velocity distributions and illustrate a multiscale postprocessing system that can be used to generate coarse-mesh closures for subchannel and porous media tools, and provide a dataset with average velocity for comparison with coarse-mesh tools.

查看原文本刊更多论文

钠快堆组件间旁路流动的CFD模拟

钠快堆（SFRs）的组件间流动是燃料组件管道外的旁路流道。通过这种薄间隙传递的热量是核心径向膨胀的重要组成部分，其中热流体，中子和固体力学之间的耦合导致了随时间变化的管道弯曲。这些几何变化可以构成瞬态总反应性响应的重要部分，但难以高保真地建模。组合流也是自然对流冷却过程中一种重要的换热方式。为了提高我们对装配间流的理解，本文提供了19束快堆堆芯装配间流的NekRS - Reynolds平均Navier-Stokes （RANS）和大涡模拟（LES）。时间平均LES与k-τ RANS模型相比相当好，尽管RANS无法捕获在管道-管道间隙和开放外围区域之间流动面积发生较大变化时发生的横流。我们预测了速度分布，并说明了一个多尺度后处理系统，该系统可用于为子通道和多孔介质工具生成粗网格闭包，并提供了一个具有平均速度的数据集，用于与粗网格工具进行比较。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Nuclear Engineering and Design 工程技术-核科学技术

CiteScore

3.40

自引率

11.80%

发文量

377

审稿时长

5 months

期刊介绍： Nuclear Engineering and Design covers the wide range of disciplines involved in the engineering, design, safety and construction of nuclear fission reactors. The Editors welcome papers both on applied and innovative aspects and developments in nuclear science and technology. Fundamentals of Reactor Design include: • Thermal-Hydraulics and Core Physics • Safety Analysis, Risk Assessment (PSA) • Structural and Mechanical Engineering • Materials Science • Fuel Behavior and Design • Structural Plant Design • Engineering of Reactor Components • Experiments Aspects beyond fundamentals of Reactor Design covered: • Accident Mitigation Measures • Reactor Control Systems • Licensing Issues • Safeguard Engineering • Economy of Plants • Reprocessing / Waste Disposal • Applications of Nuclear Energy • Maintenance • Decommissioning Papers on new reactor ideas and developments (Generation IV reactors) such as inherently safe modular HTRs, High Performance LWRs/HWRs and LMFBs/GFR will be considered; Actinide Burners, Accelerator Driven Systems, Energy Amplifiers and other special designs of power and research reactors and their applications are also encouraged.