Hydrogen embrittlement in fuel cladding in advanced candu and generation IV reactors

加拿大签署的京都议定书和悉尼协议将需要相当大的努力来限制绿色房屋气体排放，因此依赖清洁能源。核能被认为是未来的清洁能源，新的先进CANDU反应堆提供更高的燃料燃耗，更高的效率和出色的操作安全性。此外，加拿大正在设计第四代反应堆，这些反应堆也被考虑为生产清洁燃料氢提供热量。这些先进反应堆的性能和高效率与更高的操作温度有关，必须做出重大努力来提高高温环境中材料的性能和预期寿命。本提案旨在评估微观结构在燃料包壳氢脆中的作用，以提高燃料包壳管在较高工作温度下的预期寿命。拟议的研究目标是改进先进CANDU反应堆中使用的Zr-4包壳的工艺和结构，以及未来在第四代反应堆中应用的新型合金E110（Zr-1Nb）。新的实验技术的取向成像，尚未应用于包壳脆化的研究，将使我们第一次检查的作用，晶界的结构在氢化物的形成，并引入微观织构和晶界工程的概念，提出改善氢脆的方法。基于所获得的结果，新的微观结构的氢化物脆化的计算机模型将被开发，这将允许模拟不同的锆合金微观结构的过程。模拟结果将允许定义最佳的微观结构，并可用于下一阶段的研究，以创新阿恩普赖尔（安大略）G. E-Hitachi工厂的燃料芯块制造工艺。

The signing of the Kyoto protocol and Sydney agreement by Canada will require considerable efforts to limit green house gas emission and therefore to rely on clean energy. Nuclear energy is considered, a clean energy of the future and new advanced CANDU reactors offer higher fuel burn-up, higher efficiency and excellent safety of operation. In addition Canada is engaged in design of the Generation IV reactors that are also considered for providing heat for production of clean fuel, hydrogen. Performance and high efficiency of these advanced reactors is linked to higher operating temperature and significant efforts have to be made to improve the performance and life expectancy of materials in high temperature environment. The present proposal is aiming to evaluate a role of microstructure in the hydrogen embrittlement of fuel cladding in order to improve life expectancy of fuel cladding tubes at higher operating temperatures. The proposed research targets improvement of processing and structure of Zircaloy-4 cladding to be used in advanced CANDU reactors and novel alloy, E110 (Zr-1Nb) for future application in the reactors of the IV generation. Novel experimental technique of orientation imaging, that was not yet applied in cladding embrittlement research, will allow us for the first time to examine a role of structure of grain boundaries in hydride formation and to introduce concepts of microtexture and grain boundary engineering to propose methods for improving hydrogen embrittlement. Based on the results obtained novel microstructural computer model of hydride embrittlement will be developed that will allow to simulate the process for different Zr alloys microstructures. The result of simulation will allow to define optimum microstructure and can be used in the next stage of research to innovate process of manufacturing fuel pellets in G.E-Hitachi plant in Arnprior (Ontario)