Application of advanced simulation tools for multiphysics evaluation of the SMR cores

小型模块化反应堆(SMR)具有部署时间短、投资成本低、可设在偏远地区等优点，是现代大型核电站的一种有吸引力的替代方案。SMR的功率从几十兆瓦到数百兆瓦不等，可以用于发电、供暖、海水淡化和其他工业任务。这个博士项目专注于一种先进的反应堆堆芯模拟方法，该方法结合了效率和准确性，并有可能被工业使用。一个关键点将是确定与传统大型反应堆相比，SMR(硼和无硼)在建模和模拟方面面临的挑战。这将使人们能够发现有效的方法，利用先进的多物理和多尺度模拟技术准确地研究运行参数的敏感性。将使用先进的建模和模拟工具的组合，例如全堆芯模拟器DYN3D、中子输运解算器Lotus和OpenMC以及子通道热工-水力学程序CTF。利用这些先进的多尺度和多物理工具来创建计算效率高、精度高的模型的方法有可能成为评估SMR安全和性能的有效工具。该模型将为整个反应堆堆芯提供组件级别的耦合反应堆物理，同时仅在选定的小型模块化反应堆(SMR)组件中实现详细的逐个管脚级别的模拟。特别是，简化的反应堆物理耦合(DYN3D)程序将被用来模拟燃料组件级别的所有核反应堆堆芯，以确定感兴趣的区域。之后，改进的反应堆物理耦合(LOTUS+CTF)程序将被用来模拟燃料组件在燃料销水平上的指定感兴趣区域。这种方法将允许为SMR磁芯的准确建模和模拟提供识别路径，而无需计算昂贵的全芯逐针模拟，使其对所开发方法的工业应用具有吸引力。

Small modular reactors (SMRs) are an attractive alternative to modern large-scale nuclear power plants due to their advantages, such as shorter deployment time, smaller capital costs, and the ability to be sited in remote locations. SMRs vary in power from tens to hundreds of MW and can be used for electricity generation, heating, water desalination and other industrial tasks. This PhD project is focused on a methodology for the advanced reactor core simulation that combines efficiency and accuracy and can potentially be used by industry. A key point will be identifying the challenges in modelling and simulating the SMRs (boron and boron-free) compared to traditional large-scale reactors. This will enable the discovery of efficient methods to accurately study the sensitivity of operational parameters using advanced multiphysics and multiscale simulation techniques. A combination of advanced modelling and simulation tools will be used, such as the full-core simulator DYN3D, the neutron transport solvers LOTUS and OpenMC, and the subchannel thermal-hydraulics code CTF. The approach of utilising those advanced multiscale and multiphysics tools to create a computationally efficient model with high accuracy has the potential to be an efficient tool in the evaluation of SMRs' safety and performance. This model will be designed to deliver coupled reactor physics at the assembly level for the entire reactor core while achieving a detailed pin-by-pin level simulation exclusively in selected assemblies for Small Modular Reactors (SMRs). In particular, the simplified coupled reactor physics (DYN3D) code will be used to simulate all the nuclear reactor cores at the level of fuel assembly to define an area of interest. Following that, the Improved coupled reactor physics (LOTUS + CTF) code will be used to simulate the designated area of interest in the fuel assembly at the fuel pin level. This approach will allow identification paths for accurate modelling and simulation of the SMR cores without the computationally expensive full-core pin-by-pin simulations, making it attractive for the industrial application of the developed methodology.