The US plan for high-level nuclear waste includes the immobilization of long-lived radionuclides in glass or ceramic waste forms in stainless-steel canisters for disposal in deep geological repositories. Here we report that, under simulated repository conditions, corrosion could be significantly accelerated at the interfaces of different barrier materials, which has not been considered in the current safety and performance assessment models. Severe localized corrosion was found at the interfaces between stainless steel and a model nuclear waste glass and between stainless steel and a ceramic waste form. The accelerated corrosion can be attributed to changes of solution chemistry and local acidity/alkalinity within a confined space, which significantly alter the corrosion of both the waste-form materials and the metallic canisters. The corrosion that is accelerated by the interface interaction between dissimilar materials could profoundly impact the service life of the nuclear waste packages, which, therefore, should be carefully considered when evaluating the performance of waste forms and their packages. Moreover, compatible barriers should be selected to further optimize the performance of the geological repository system.

美国的高放核废料计划包括将玻璃或陶瓷废料形式的长寿命放射性核素固定在不锈钢罐中，以便在深层地质储存库中处置。在这里，我们报告说，在模拟储存库条件下，不同屏障材料的界面处的腐蚀可能会显着加速，这在当前的安全和性能评估模型中尚未考虑。在不锈钢与模型核废料玻璃之间以及不锈钢与陶瓷废料形式之间的界面处发现了严重的局部腐蚀。加速腐蚀可归因于有限空间内溶液化学和局部酸碱度的变化，这显着改变了废物形式材料和金属罐的腐蚀。由不同材料之间的界面相互作用加速的腐蚀可能会深刻影响核废料包装的使用寿命，因此在评估废物形式及其包装的性能时应仔细考虑这一点。此外，应选择兼容的屏障，以进一步优化地质处置库系统的性能。