Exploring 2D Graphene as Atomic Armor to Protect Uranium from Ambient Corrosion

Uranium (U) is a nuclear material with tremendous technological importance. One outstanding challenge in preserving its intrinsic nuclear properties is its high susceptibility to ambient corrosion. The corrosion, initiates at surfaces and interfaces, can form different phases, alter the dimensions of components, and even cause surface spalling, thus degrade the nuclear performance. Protective coatings are effective means to prevent metals from corrosive environments. However, anticorrosion coatings, when applied to actinides including U, faces a unique challenge from self-irradiation, which can degrade coatings’ integrity by radiation damage and thus compromise the long-term efficacy of the applied coatings for corrosion protection.<br/>This research aims to explore the feasibility of 2D graphene coating as atomic armor to protect U from ambient corrosion. Compared with traditional vapor-deposited film coatings, the defect formation in 2D material coatings is randomly distributed across layers, thus drastically reducing gas permeation paths. This unique 2D characteristics enables us to use significantly thinner coatings to achieve required anticorrosion efficacy; thus, can better preserve nuclear properties of the U material by minimizing unwanted “impurities” from the anticorrosion coatings itself.<br/>Ion beams are used to mimic U self-irradiation environments including high energy alpha particle ionizations and heavy daughter product recoil cascades; thus, the accelerated irradiation doses of years and decades equivalent U-shelf lifetime can be effectively evaluated at the laboratory scale. Raman spectroscopy is used to evaluate irradiation stability of our 2D graphene coatings. Sieverts corrosion techniques are used to evaluate anticorrosion efficacy of the 2D graphene coatings when uncoated and coated U surfaces are exposed to hydrogen gas environments.