Can the canisters be monitored for leaks? And is any long-term monitoring expected (post-closure)?
During emplacement and while the borehole is open, monitors can be placed on or near the exterior of the casing to record radiation, temperature, pressure, and other aspects of the repository environment. During the open period, fluids from the repository can also be sampled and monitored. Canister emplacement operations will also be closely monitored to evaluate any potential distress during emplacement. Together, these measures can effectively provide information on the integrity of canisters and the evolution of the repository environment and can inform decisions on repository closure and sealing.
In the post-closure environment, no direct measurements from inside the repository will be possible, however, similar measurements could be done from monitoring wells nearby or through sampling closer to the surface. Monitoring for “performance confirmation” after repository closure is possible, using surface geophysical methods, near-surface sampling and monitoring, borehole-based geophysical methods, dedicated monitoring boreholes (vertical or running parallel to the disposal section), and data from sensors embedded in the disposal borehole during repository construction.