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).

这个塞拉菲尔德有限公司和NDA赞助的博士项目的目的是开发新的数学和计算方法，用于模拟含有特殊核材料（SNM）的松散耦合系统的相互作用阵列的核临界漂移行为[1，2，3，4]其中一些阵列组件是次临界的，而一些是超临界的，或者其中一个无关的（或外部）中子源被引入系统中。在这项拟议的研究中采取的“确定”多点核反应堆动力学方程中的耦合系数的方法将是使用几何形状一致性方法，该方法将精确地对各个子系统的几何形状进行建模（例如，圆筒、盒子或其他此类容器）。这种几何一致性方法将使用基于伴随的加权来计算中子离开一个子系统并进入另一个子系统的重要性。这具有重要的优点，即也可以使用单一方法来确定多点核反应堆动力学方程中所需的核反应堆动力学参数（例如，平均生成时间、β有效、基模伴随加权源项和伴随加权前体浓度）[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特性导出一组热工水力方程。例如，如果它是粉末系统，则润湿粉末的物理和热工水力学将是适当的（类似于乳液、胶体、悬浮液、金属系统、污泥、饼状物和浆料）。