High-fidelity and high-resolution simulation of two different rod ejection accidents in a NuScale-like small modular reactor with conventional and accident tolerant fuels

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

Nuclear Engineering and Design Pub Date : 2025-05-30 DOI:10.1016/j.nucengdes.2025.114183

Zsolt Soti , Paul Van Uffelen , Arndt Schubert , Ville Valtavirta , Riku Tuominen , Heikki Suikkanen , Ville Rintala , Andre Gommlich , Emil Fridman , Yurii Bilodid , Luigi Mercatali , Victor Hugo Sanchez-Espinoza

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引用次数: 0

Abstract

This work presents a high-fidelity pin-by-pin simulation approach for a NuScale-like Small Modular Reactor core during a rod ejection accident (REA). We coupled 3D Monte Carlo neutron transport (Serpent), subchannel thermal–hydraulic (SUBCHANFLOW) and fuel performance (TRANSURANUS) codes using the Interface for Code Coupling (ICoCo), which is part of the EU’s Salome open source platform. To resolve fuel intra-assembly details, we simulated all the fuel rods and channels, subdividing them into axial slices and transferred calculated data between the codes using scalar fields saved in memory variables. Two different REA scenarios were modelled, and the behaviour of fresh-loaded cores with conventional UO₂ fuel with Zr-4 cladding and accident tolerant fuel (ATF) materials, U₃Si₂ fuel with FeCrAl cladding, were analysed. In both scenarios, the control rod was ejected within 0.1 s, followed by a SCRAM after two seconds. In the first moderate scenario, the control rod ejection occurred at 75% of the nominal power, whereas in the second accident scenario, it occurred at hot zero power (HZP) conditions. In the first scenario, the power increase was around 25%, while in the HZP case it amounted up to 600% and 300% of the nominal power for the core loaded with UO₂ and ATF-fuel and cladding, respectively. Detailed calculations were conducted on a High-Performance Computer (HPC). The results demonstrated the robustness and flexibility of the coupled code system, providing full-core behaviour and rod-level safety parameters and predicting as needed during the safety analysis support of the licensing processes. This paper outlines the system setup, presents rod-level results and underlines the usefulness to assess the performance of SMR-cores loaded with different fuel types under various REA scenarios. In the scenarios considered, we did not observe significant fuel rod deformations, and the core loaded with ATF-fuel and cladding showed a large margin to melting.

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采用常规燃料和事故耐受性燃料的nuscal型小型模块化反应堆中两种不同棒弹射事故的高保真度和高分辨率模拟

这项工作提出了一种高保真的针接针模拟方法，用于nuscale类小型模块化反应堆堆芯在棒射事故（REA）期间的模拟。我们使用代码耦合接口（ICoCo）来耦合3D蒙特卡罗中子输运（Serpent）、子通道热流（SUBCHANFLOW）和燃料性能（TRANSURANUS）代码，ICoCo是欧盟Salome开源平台的一部分。为了解决燃料组件内部的细节，我们模拟了所有燃料棒和通道，将它们细分为轴向切片，并使用存储在内存变量中的标量场在代码之间传输计算数据。模拟了两种不同的REA情景，并分析了使用Zr-4包层的传统UO2燃料和带有FeCrAl包层的U3Si2燃料（ATF）材料的新鲜装载堆芯的行为。在这两种情况下，控制棒在0.1秒内弹出，然后在两秒后弹出一个ram。在第一种中等情况下，控制棒弹射发生在标称功率的75%，而在第二种事故情况下，它发生在热零功率（HZP）条件下。在第一种情况下，功率增加约为25%，而在HZP情况下，它分别达到装载UO2和atf燃料和包层的堆芯标称功率的600%和300%。在高性能计算机（HPC）上进行了详细计算。结果证明了耦合代码系统的鲁棒性和灵活性，提供了全核心行为和棒级安全参数，并在许可过程的安全分析支持中根据需要进行预测。本文概述了系统设置，展示了棒级结果，并强调了在各种REA情景下评估装载不同燃料类型的smr堆芯性能的有用性。在考虑的情况下，我们没有观察到明显的燃料棒变形，并且装载了atf燃料和包壳的堆芯显示出很大的熔化余地。

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.