Multi-objective Optimization Capability for Heterogeneous LWR Fuel Assemblies and Cores

对于某些核燃料循环，特别是那些涉及高浓缩度的核燃料循环，或者对于混合氧化物（MOX）燃料，在逐段基础上或逐销基础上径向地改变燃料的性质以及沿组件轴向沿着改变燃料的性质是有益的。在堆芯内包括多个燃料组件设计，利用对总体堆芯性能的径向分区和/或“棋盘格”效应也是有益的。燃料组件和堆芯设计中的异质性不可避免地增加了燃料制造成本和待搜索的设计空间的大小，因此，有能力严格和系统地探索在堆芯燃料性能目标以及异质组件和堆芯设计的制造成本将有助于决策。多目标优化方法的发展使这种能力的发展成为现实的命题。该项目是由弗雷泽-纳什咨询公司代表英国国防部管理的维持独立核专业知识（SINE）计划的一部分。项目目标一个用于非均质轻水堆燃料组件和堆芯的原型计算设计系统，包括优化和反应堆物理和热工水力分析代码的集成，将开发的目标：1。论证了多目标优化方法在反应堆燃料和堆芯设计中的有效性和实用性;2.发展联合王国在核反应堆燃料和堆芯设计方面的国家能力和方法。

For some nuclear fuel cycles, particularly those involving high enrichment, or for mixed-oxide (MOX) fuel, there are benefits in varying the properties of the fuel radially, on a section-by-section basis or a pin-by-pin basis, and axially along the assembly. There are also benefits in including multiple fuel assembly designs within the core, exploiting radial-zoning and/or "checker-boarding" effects on overall core performance.Heterogeneity in fuel assembly and core design inevitably increases fuel fabrication costs and the size of the design space to be searched, so a capability to explore rigorously and systematically the trade-offs between in-core fuel performance objectives and the fabrication costs of heterogeneous assembly and core designs would be a helpful aid to decision-making. Advances in multi-objective optimization methods make the development of such a capability a realistic proposition.This project is part of the Sustaining Independent Nuclear Expertise (SINE) programme managed by Frazer-Nash Consultancy on behalf of the UK Ministry of Defence.Project objectivesA prototype computational design system for heterogeneous LWR fuel assemblies and cores, involving the integration of optimization and reactor physics and thermal-hydraulic analysis codes, will be developed with the aims of:1. Demonstrating the effectiveness and the utility of multi-objective optimization methods for reactor fuel and core design;2. Developing UK national capability and methods in the design of nuclear reactor fuel and cores.