Modelling and Simulation of Transient Nuclear Criticality Excursions Containing Special Nuclear Materials

包含特殊核材料的瞬态核临界偏移的建模和仿真

• 批准号: 2891950
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2891950
• 关键词: Modelling; Simulation; Transient; Nuclear; Criticality

The aim of this Sellafield Ltd and NDA sponsored PhD project is to develop novel mathematical and computational methods for modelling the nuclear criticality excursion behaviour of interacting arrays of loosely coupled systems containing special nuclear material (SNM) [1, 2, 3, 4] where some of the array components are sub-critical and some are super-critical or where an extraneous (or external) neutron source is introduced into the system. The approach taken in this proposed research to "determine" the coupling coefficients in the multi-point nuclear reactor kinetics equations will be to use a geometry conforming approach that will exactly model the geometry of the individual sub-systems (e.g., cylinders, boxes or other such vessels). This geometry conforming approach will use adjoint based weighting to also calculate the importance of neutrons leaving one sub-systems and entering another sub-system. This has the important advantage that a single methodology can also be used to determine the nuclear reactor kinetics parameters needed in the multi-point nuclear reactor kinetics equations (e.g., mean generation time, beta-effective, fundamental mode adjoint weighted source terms and, adjoint weighted precursor concentrations) [39]. For each of the different sub-systems a set of thermal-hydraulic equations will be derived depending upon the physics of the individual sub-system component of the loosely coupled system. For example, if it were a powder system then the physics and thermal hydraulics of wetted powders would be appropriate (similar with emulsions, colloids, suspensions, metallic systems, sludges, cakes, and slurries).

该Sellafield Ltd和NDA赞助的PHD项目的目的是开发新型的数学和计算方法，用于建模含有特殊核材料（SNM）的松散耦合系统相互作用阵列的核临界行驶行为（SNM）[1,2,3,4] [1,2,3,4]，其中一些阵列组件是超级批评系统的，或者是一个超级质量的系统，或者是一个超级典型的系统，或者是一个超级典型的系统。在这项拟议的研究中采用的方法是“确定”多点核反应器动力学方程中的耦合系数，将是使用几何形状构象方法，该方法将精确地模拟单个子系系统的几何形状（例如，圆柱体，盒子，盒子，盒子或其他此类容器）。这种几何形状符合方法将使用基于伴随的加权来计算中子的重要性，使一个子系统并进入另一个子系统。这具有重要的优势，即也可以使用单个方法来确定多点核反应器动力学方程中所需的核反应器动力学参数（例如，平均生成时间，Beta效率，基本模式的伴随加权源项和相邻的加权前体浓度）[39]。对于每个不同的子系统，将根据松散耦合系统的各个子系统组件的物理学来得出一组热氧化型方程。例如，如果是粉末系统，那么湿粉的物理和热液压是合适的（与乳液，胶体，悬浮液，金属系统，泥石，蛋糕，蛋糕和浆液相似）。