Increasing Confidence in Localized Corrosion Allowance of Copper Coated Steel Containers

加拿大对其使用过的核燃料的长期管理计划是将使用过的核燃料安全地存放和隔离在一个深层地质处置库中。根据国际最佳做法，将使用天然和工程屏障，以安全和长期地封闭使用过的核燃料。工程屏障系统的一个关键组成部分是用过的燃料容器（UFC），它由一个坚固的内部钢容器组成，容器上涂有耐腐蚀的铜涂层。加拿大设计的独特之处在于薄铜涂层，这是加拿大创新的结果，因为原型制造是由安大略工业在魁北克和加拿大研究机构的支持下进行的。然而，厚度的减少值得对涂层的腐蚀行为进行广泛的评估，以确保其寿命，以安全地遏制和隔离加拿大人和环境中的放射性材料。涂层的微观结构和DGR溶液化学影响其腐蚀行为。深入研究涂层的微观结构和辐射产物如何影响非均匀（局部）腐蚀机制，对于避免UFC穿透和放射性暴露于周围环境至关重要。该联盟项目的主要目标是使用多尺度电化学方法提高对UFC安全性和局部腐蚀容限的信心。将采用先进的电化学方法，在腐蚀性DGR条件下（包括伽马辐射暴露）探索UFC局部腐蚀的可能性和长期预测，以加深我们对铜腐蚀的理解，并增强我们对拟议的UFC/DGR系统的信心。这个为期3年的项目由核废物管理组织（NWMO）和NSERC资助，将被整合到合作伙伴的制造战略和许可阶段，以建立一个安全可靠的处置库。

Canada's plan for the long-term management of its used nuclear fuel is to safely contain and isolate the used nuclear fuel in a deep geologic repository (DGR). In line with international best practices, both natural and engineered barriers will be used for safe and long-term containment of used nuclear fuel. A key component of the engineered barrier system is the used fuel container (UFC) that consists of a strong interior steel container coated with a corrosion resistant copper coating. What makes the Canadian design unique is the thin copper coating, a result of Canadian innovation, as prototype fabrication has been performed by Ontario industry with support from Quebec and Canadian research institutes. However, this decrease in thickness merits the extensive evaluation of the coating's corrosion behaviour to ensure their longevity for the safe containment and isolation of radioactive materials from Canadians and environment. The coatings' microstructure and the DGR solution chemistry influence their corrosion behaviour. A thorough investigation on how the coating's microstructure and radiation products influence non-uniform (localized) corrosion mechanisms is of extreme importance to avoid penetration of the UFC and exposure of radioactivity to the surroundings.This Alliance project's key objective is to increase the confidence in the safety and localized corrosion allowance of the UFCs using a multiscale electrochemical approach. The likelihood and long-term prediction of localized corrosion of the UFCs will be explored in aggressive DGR conditions, including gamma radiation exposure, using advanced electrochemical methods to further our understanding of copper corrosion and confidence in the proposed UFC/DGR system. This 3-year project, funded by the Nuclear Waste Management Organization (NWMO) and NSERC, will be integrated into the partner's manufacturing strategies and licensing phase to build a safe and reliable repository.