Operation characteristics analysis of supercritical CO2 reactor based on neutronics and thermal-hydraulics coupling

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

Nuclear Engineering and Design Pub Date : 2025-03-08 DOI:10.1016/j.nucengdes.2025.113947

Yuchen Niu , Dabin Sun , Yuandong Zhang , Lei Chen , Minjun Peng , Genglei Xia

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引用次数: 0

Abstract

Small Modular Reactors (SMRs) have emerged as a focal point in future nuclear systems, owing to their high energy density, simple structure, flexible configuration, and extended endurance. The innovative nuclear system using supercritical carbon dioxide (SCO₂) Brayton cycle as the energy conversion system offers notable benefits such as high conversion efficiency, compact layout. Additionally, SCO₂ can achieve a greater density difference compared to water, potentially enabling an enhancement in inherent safety through natural circulation, which renders it stand out in SMRs. Nonetheless, the distinct thermo-physical properties of SCO₂ present challenges in understanding the multi-physics coupling characteristics of this system. Current operation characteristics analysis focus on individual physical fields, lacking the effective methods to calculate the inherent multi-physics coupling characteristics of SCO₂ reactors. This study introduced a neutronics and thermal-hydraulics coupling method for SCO₂ cooled reactors, based on the thermal-hydraulics analysis capabilities of RELAP5-SCO₂ and the three-dimensional neutron physics analysis capabilities of SIM-CORE. The coupling framework between the RELAP5-SCO₂ and the SIM-CORE was established. The time step control strategy, spatial grid mapping technique, and the method for transmitting coupling parameters between above two programs were described in detail. The proposed methods and developed models were validated by accurately representing the multi-physics coupling features of a 15MW_th SCO₂ direct cooled micro-reactor. Meanwhile, the multi-physics coupling characteristics under the typical multi-power operation conditions and representative accident conditions, including reactivity-initiated accident, loss of flow accident and loss of coolant accident, were analyzed. The three-dimensional core neutronics and thermal-hydraulics coupling program developed in this paper can enhance the understanding of the transient operating characteristics of SCO₂ gas-cooled reactors and the strong nuclear-thermal coupling effects in accident scenarios, providing theoretical support and technical assistance for the research and development and safety analysis of SCO₂ gas-cooled reactors.

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基于中子与热工耦合的超临界CO2反应器运行特性分析

小型模块化反应堆（SMRs）由于其高能量密度、结构简单、配置灵活、寿命长等优点，已成为未来核系统发展的热点。采用超临界二氧化碳（SCO2）布雷顿循环作为能量转换系统的创新核系统具有转换效率高、布局紧凑等显著优点。此外，与水相比，SCO2可以实现更大的密度差，通过自然循环潜在地增强固有安全性，这使得SCO2在smr中脱颖而出。然而，SCO2独特的热物理性质给理解该系统的多物理场耦合特性带来了挑战。目前的运行特性分析主要集中在单个物理场，缺乏有效的方法来计算SCO2反应器固有的多物理场耦合特性。本研究基于RELAP5-SCO2的热工分析能力和SIM-CORE的三维中子物理分析能力，提出了一种SCO2冷却堆的中子热工耦合方法。建立了RELAP5-SCO2与SIM-CORE的耦合框架。详细介绍了时间步进控制策略、空间网格映射技术以及两种程序之间耦合参数的传递方法。通过对15mwsco2直冷微堆多物理场耦合特性的准确表征，验证了所提方法和模型的正确性。同时，分析了典型的多功率运行工况和典型事故工况（反应性引发事故、失流事故和失冷剂事故）下的多物理场耦合特性。本文开发的三维堆芯中子学与热工水力学耦合程序可以加深对SCO2气冷堆瞬态运行特性和事故情景下强核-热耦合效应的认识，为SCO2气冷堆的研发和安全性分析提供理论支持和技术协助。

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.