Mathematical and Computational Modelling for Nuclear Criticality Safety Analysis and Assessment of Interacting Arrays of Loosely Coupled Systems

其目的是开发新的数学和计算方法，以模拟含有裂变材料的松散耦合系统相互作用的阵列的核临界漂移行为，其中一些阵列组件是亚临界的，一些是超临界的，或者在系统中引入外部(或外部)中子源的情况下。就燃料循环的前端和后端而言，核材料存在于非常广泛的不同物理形式和物质相中，从金属系统到粉末、蛋糕、泥浆、污泥、乳化液、胶体和悬浮液。这种材料通常储存在储存设施和建筑物内具有不同几何形状的各种不同容器中，通常作为这种储存容器的阵列。含有裂变材料的相互作用的阵列大致可分为定义良好的阵列或定义不明确的阵列。在定义明确的相互作用阵列中，裂变单位或机构的组成、密度、大小、形状和位置是“先验的”，具有很好的特征或已知。此外，反射和调节材料的分布和组成被定义得相当精确。总体而言，该博士项目将为国防部承包商提供一套独特的方法，可用于模拟目前可能出现的更广泛的情景。大多数特殊核材料(SNM)以各种形式储存在设施中，并且通常以规则间隔的阵列形式储存。核燃料循环的其他部分也会对这些方法感兴趣。

The aim is to develop novel mathematical and computational methods for modelling the nuclear criticality excursion behaviour of interacting arrays of loosely coupled systems containing fissile material 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. In terms of the front and back end of the fuel cycle nuclear material is found in a very wide range of different physical forms and material phases from metallic systems, to powders, to cakes, to slurries, to sludges, to emulsions, to colloids and also suspensions. This material is often stored in a wide range of different containers with different geometries within storage facilities and buildings often as arrays of such storage containers. Interacting arrays containing fissile material can broadly be categorised as well defined arrays or ill-defined arrays. In well-defined interacting arrays the composition, density, size, shape and position of the fissile units or bodies is "a priori" well characterised or known. In addition the distribution and composition of reflecting and moderating materials is defined fairly precisely.Overall this PhD project would provide the MoD contractor with a unique set of methods that can be used to model a wider range of scenarios that currently possible. Most special nuclear material (SNM) is stored in facilities in a wide variety of forms and usually in regularly spaced arrays. The methods will also be of interest to other parts of the nuclear fuel cycle as well.