The Community Liaison Committee recently heard from a Western University researcher about experiments that she and a team of experts have been conducting related to the rate of corrosion of the used nuclear fuel containers designed for the proposed deep geological repository (DGR).
The purpose of the work is to expose the containers to a highly corrosive environment to determine the rate of corrosion in extreme conditions. Called the Ocean Module Experiment, it involves placing copper inside bentonite clay buffer boxes and submerging them in the ocean in multiple locations at various depths.
Claire Tully, a Ph.D. candidate, explained that the experiment tested the three types of copper used in the used nuclear fuel containers. These include wrought copper, cold spray copper, and electro-deposited copper.
The study sites are located off the coast of Vancouver Island and include the Saanich Inlet at 90 m deep, the Barkley Canyon at 980 m deep and the Cascadia Basin at 2,000m deep.
The experiment exposes the copper coatings to a variety of corrosive conditions that could be experienced in a DGR environment. The environment includes high pressure, saline, oxygen deficient, and with active microbes that influence corrosion.
The study has so far found low average rates of corrosion after six months.
Technically, the experiment determined that 0.0004 cm of copper corrosion per year is the highest degree of corrosion across all locations and types of copper. There will be additional testing with follow up at one, three, five and seven years on samples in the Cascadia basin.
The Nuclear Waste Management Organization (NWMO) collaborates with research scientists to conduct testing on various components involved with a DGR. The project includes Western University, as well as experts at University of Waterloo, York University, and the University of Toronto.
In addition to the NWMO, funding was provided by the Ontario Research Fund, and the Natural Sciences and Engineering Research Council of Canada.
