A combined peridynamics and FE modelling approach to nuclear power plant materials

英国政府在最近的2008年白皮书中明确表示，核能是英国能源结构的重要组成部分，以确保供应安全并承诺减少二氧化碳排放。英国核监管局（Office of Nuclear Regulation）最近发布的一份关于福岛核事故的报告证实，福岛核事故表明没有理由限制英国的核运营或新建核电站，预计法国电力公司（EDF）将在2012年开始在欣克利角（Hinkley Point）建造第一座新核电站。也许从福岛事故，特别是在日本吸取的一个关键问题/教训是，需要继续研究核安全，以支持现有的和新建的核电站方案。直到最近，英国对核能的研究相对较少，因此真正从事这一领域的年轻学者也相对较少。如果新的建设计划要取得成功，并帮助重建英国作为该领域世界领导者的声誉，那么在核工程学科方面培养新的年轻有才华的工程师和物理学家的需求也越来越大。提出这个建议是为了试图解决其中的一些问题，同时探索一个新的不断发展的建模领域，即周围动力学，它在模拟核工程材料领域的许多问题方面具有很大的潜力。该项目旨在研究迄今为止难以建模的两个核燃料问题：核燃料中的球团包层相互作用（PCI）和水冷反应堆锆合金包层的氧化物相变/碎裂。这些问题是理想的混合有限元(FE) -周动力学建模方法。PCI和氧化物的生长和剥落都需要一个模型，该模型能够处理在复杂应力状态、几何形状下与脆性材料（UO2陶瓷燃料）结合的韧性材料（包层），并结合传热和材料非均质性。周动力学方法能够模拟有缺陷的材料，而不存在有限元方法固有的一些数值问题。然而，结合这两种建模技术可以将两种技术的优点结合起来。本项目将开发一个周期动力学实现到有限元代码Abaqus。然后将进一步开发模型，以模拟PCI的具体问题和所描述的氧化物剥落问题。该项目还将在核燃料建模领域培养一名新的年轻博士后研究员和一名早期职业学者。

The UK government made it clear in a recent white paper of 2008 that nuclear energy was a vital part of the UKs energy mix to ensure both security of supply and a commitment to reduction in CO2 emissions. The recent Office of Nuclear Regulation Weightman report on the Fukushima accident has confirmed that Fukushima showed no reason to curtail nuclear operation or nuclear new build in the UK and in 2012 it is expected that EDF will start work on the first new nuclear power station at Hinkley Point. Perhaps one key issue/lesson learnt from the Fukushima accident, especially in Japan, was the need for continued research into nuclear safety to support existing and new build nuclear power plant programmes. Until recently there has been relatively little UK research into nuclear power and as such there are also relatively few young academics truly in the field. There is also a growing need to train new young talented engineers and physicists in nuclear engineering disciplines if the new build programme is to be successful and to help rebuild the UKs reputation as a world leader in this field. This proposal is made to try to address some of these issues and at the same time explore a new growing area of modelling, known as peridynamics, with great potential for modelling many problems within the nuclear engineering materials area. The project aims to investigate two nuclear fuel problems thus far difficult to model: pellet-cladding interactions (PCI) in nuclear fuels and oxide phase change/spallation on zirconium alloy cladding of water-cooled reactors. These problems are ideal for a mixed finite element (FE) -peridynamics modelling approach. Both PCI and oxide growth and spallation require a model that is able to deal with a ductile material (cladding) bonded to a brittle material (UO2 ceramic fuel) under complex stress states, geometries and incorporating heat transfer and material heterogeneity. The peridynamics approach is able to model material with defects without some of the numerical issues inherent within the FE approach. However, combining the two modelling techniques can bring the advantages of both techniques together.This project will develop a peridynamics implementation into the finite element code Abaqus. The models will then be developed further to model the specific problems of PCI and oxide spallation problems described. The project will also develop a new young post doctoral researcher and a early career academic in the field of nuclear fuel modelling.