Release calculations in a repository of the very long tunnel type.

摘要

The VLH and KBS-3 are two alternative repository designs for high level waste. The repositories differ mainly in the layout and the canister design. In the VLH repository the canisters are placed horizontally in long boreholes. In the KBS-3 repository every canister is placed vertically in repository holes in the tunnel floor. If a small hole forms in the canister wall the nuclides diffuse through this hole into the backfill surrounding the canister. From the backfill the nuclides migrate by different pathways into the mobile water in the fractures in the rock. A study of comparison of the nuclide release in the two alternative repositories shows releases in the same order of magnitude for a given nuclide. A quantitative assessment of the importance of the different pathways, the influence of the location of the fracture and fracture zone in relation to the damage in the canister wall and the influence of the size of the small hole (damage) is made. The assessment for the VLH-repository shows that the main pathway is that to the disturbed zone and the fracture location in relation to the damage has no large influence in the release. (Atomindex citation 24:039323)