Assessment of technologies to produce corrosion resistant coatings on nuclear waste disposal canisters

A strategy for reducing the cost of nuclear waste canisters for deep geological disposal is to fabricate the core with a relatively cheap carbon steel and to clad it with a corrosion resistant coating. Corrosion resistant materials that have previously been evaluated include copper, stainless steels and Ni-based and Ti-based alloys. Several commercially available coating technologies including electrodeposition, physical vapour deposition, laser deposition, thermal and cold spray were assessed. We found that cold spray has a range of advantages over the other methods which will be highlighted, making it the coating technology of choice. Previous work on the cold spray of corrosion resistant coatings, especially in relation to nuclear waste disposal, is discussed. Maintaining the coating integrity during canister emplacement in deep boreholes is more demanding compared with conventional mined repositories. Therefore, additional design criteria related to coating abrasion and impact are recommended. Graphical abstract