Reducing risk through uncertainty quantification for past, present and future generations of nuclear power plants

为了确保国家在不确定世界中的韧性和生产率，英国需要安全、可靠的能源供应。国内核裂变工厂产生的电力对此做出了重要贡献，目前发电量约为英国需求量的六分之一。未来的聚变发电厂提供了一个愿景，即从基本上无限的燃料中产生更少的废物，更安全的能源。然而，公众对核安全的糟糕认识限制了人们的接受，同时对暴露在热、机械和辐射载荷下的关键核材料的行为缺乏了解增加了工程不确定性，从而增加了设计风险和运营成本。这项研究计划使用多尺度、多技术的方法，将高性能计算机模型与成像分析相结合，以加深对几种关键工程材料在这种压力下的机械行为的理解：*用于容纳历史上的核废料的硅陶瓷，*在当前一代核电站中用于缓和反应的石墨，*用于为未来一代核聚变的安全壳提供衬里的铍和钨。为这些重要部件的结构完整性开发更好的、经过实验验证的模型将有助于提高设计的准确性，从而降低发电和废物储存设施的建造和运营成本，并增强公众对该行业的信心。这项研究结合了两种计算方法的优点：*完全基于物理的材料模型，这种模型发展得很好，但还不适用于大型和复杂的工程系统；*经验工程模型，在它们被校准的领域很有用，但目前可转移性有限；结合严格的误差分析，创建一种可跨长度尺度传输的方法，使基本物理机制能够跟踪到工程应用。该计划的实验元素，使用X射线层析成像来创建样品内部应变和损伤的3D图像，并使用数字图像相关来跟踪实时裂纹扩展，将提供对这些关键材料在应力和观测参数下的行为的新见解，以便为建模提供信息。该项目将利用跨学科团队的优势来培养未来的专家。它将让行业合作伙伴和其他关键利益相关者参与进来，并向他们通报情况，从监管机构到工厂工人，以确保成果与英国能源发电和其他具有战略重要性的行业相关并被采纳。

To ensure national resilience and productivity in an uncertain world, the UK needs a safe, reliable energy supply. Electricity generated by domestic nuclear fission plant creates an important contribution to this, currently generating around one sixth of the UK's requirements. Future fusion-powered plant provide a vision of lower waste, higher safety energy generation from essentially limitless fuel.However, poor public perception of nuclear safety is limiting uptake, whilst poor understanding of the behaviour of critical nuclear materials exposed to thermal, mechanical and radiation loading increases engineering uncertainty, hence escalating design risk and operational cost.This programme of research uses a multi-scale, multi-technique approach, combining high performance computer models with imaging analysis, to build a deeper understanding of the mechanical behaviour of several vital engineering materials subject to such stresses: * silicon ceramics used for the containment of historic nuclear waste, * graphite used for moderating reactions in the current generation of nuclear plant, * beryllium and tungsten used to line containment vessels for future fusion generation.Developing better, experimentally-validated models of the structural integrity of such vital components will enable increased accuracy in design, hence reducing the cost of build and operation of power generation and waste storage facilities and giving greater public confidence in the industry. The research combines the strengths of two computational approaches:* Fully physically-based materials models, which are well-developed, but are not yet applicable to large and complex engineering systems;* Empirical engineering models, which are useful in the domain for which they have been calibrated, but currently have limited transferability; along with rigorous error analysis, to create an approach that is transferable across length scales, enabling the tracking of fundamental physical mechanisms through to engineering application.The experimental elements of the programme, using X-ray tomography to create 3D images of strain and damage inside samples and Digital Image Correlation to track real-time crack propagation, will provide new insight into the behaviour of these critical materials under stress and observational parameters to inform the modelling.The project will draw from the strengths of the interdisciplinary team to develop experts of the future. It will involve and inform industrial partners and other key stakeholders, from regulators to plant workers, to ensure results are relevant to and taken up by UK energy generation and other strategically important industries.