Development of a coupled Near Field and Far Field model
We have over many years developed models for the Near Field and the Far Field to describe fluid flow and nuclide transport in KBS-3 repositories. The models have been integrated and a computer code has been developed and tested. It has also been used to simulate fluid flow and nuclide transport at the Laxemar site. The results compared well with those from other rather complex codes. At present, the code is used to simulate flow and transport at the Forsmark site.
However, improvements on both the Near Field and the Far Field parts of the code can be made. For the Near Field part we see possibilities to improve the detailed description of tunnels, including the Excavation Damaged Zones around the drifts and tunnels, and of the deposition holes by taking Spalling Zones and degraded concrete at the bottom into account. Advective and diffusive transport in the backfill can also be included. For the Far Field part we see possibilities to introduce variable length channels, instead of using a regular grid of orthogonal channels. This would make the mapping of irregular features, such as fracture zones, and of irregular boundaries onto the channel network, more flexible and efficient. In addition, it is also possible to rotate the studied domains in order to improve viewing the system from different directions and angles.
In this project, we wish to improve the existing Near Field and Far Field models and adapt the coupled model to specifically simulate processes around drifts and tunnels. These improvements would facilitate simulations of inflow to drifts and tunnels, and also give more detailed results on conditions in individual deposition holes. The extended model will be used to simulate results from the ongoing Äspö experiment as a preparation for simulations of flow and transport to the drifts when the repository excavations are started.
PhD student
Pirouz Shahkarami
Principal supervisor
Assoc. Prof. Longcheng Liu
Industrial financier
Swedish Nuclear Fuel and Waste Management Company (SKB)