My name is Millicent (Millie) Castillo, and I am in the M.Sc program. Aside from research, I enjoy going on long hikes, camping with my friends and family, and playing with my Bernese mountain dog, Bella.
Research Background
Canada’s permanent plan for the long-term confinement of high-level nuclear waste is to dispose of it in a multi-barrier system within a deep geological repository (DGR). One of the key barriers is the used nuclear fuel container (UFC) comprising a carbon steel container coated with a 3-mm outer layer of copper for corrosion protection. Upon emplacement in the DGR, the Cu will initially be exposed to a warm and oxidizing environment (humid period) which will evolve to a cooler and more anoxic environment (saturated period). O2, present during the oxidizing period, can be consumed to oxidize Cu, mainly to a Cu2O film on the surface of the container. As the environment evolves towards the saturated period, SH–, produced by remote microbial activity, can further oxidize the Cu surface by first chemically converting the oxide to cuprous sulphide before causing further Cu corrosion.
The goal of my project is to develop an optimal and reproducible procedure for growing oxide films representative of what might form during the oxidizing period on SKB Cu (30-100 ppm P-doped, O-free). This is to determine how different types of oxide film will interact with sulphide as the environment becomes cooler and more anoxic. It’s important to investigate this since there are currently 2.5 million spent nuclear fuel bundles requiring safe storage for a cleaner and safer environment.