High-Temperature Corrosion Testing of Uranium Silicide Surrogates

The corrosion resistance of cerium silicide, a surrogate of uranium silicide, is investigated to gain insight into the reaction of uranium silicide with water. As-received and proton-irradiated Ce₃Si₂, CeSi₂, and CeSi_1.x monolithic pellets are subjected to corrosion tests in water at 300°C and 9 MPa for up to 48 h. Results show that an oxide layer composed of Ce_4.67 (SiO₄)₃O forms on the surface of all samples, and it grows thicker with extended exposure times. Irradiated samples corrode to a greater extent than their unirradiated counterparts, which is mainly a result of the existing post-irradiation cerium oxide and the presence of ion-induced defects. Most of the Ce₃Si₂ samples crack (as-received) or fracture (ion-irradiated) during testing, which is due to the brittleness of the samples and oxide erosion/spallation that occur during testing.