Radionuclide migration in fractured rock
Development of models for radionuclide migration in fractured rock
Most systems for long-term management of high-level nuclear waste are based upon isolation in geological formations where multiple barrier systems prevent the release of radionuclides to the biosphere. In scenarios for repository evolution, the engineered barriers are frequently assumed to fail in order to make predictions of radionuclide release. The immediate rock volume separating the repository from adjacent fracture zones and lineaments is of overwhelming importance for retarding the migration of radionuclides after release occurs following failure of the technical barrier system.
Transport through the rock occurs through a complex network of interconnected fissures and channels, which although usually no more than the thickness of a sheet of paper, can nevertheless conduct flowing water. Channelling effects in fracture planes influence the flow of water and the surface area of rock that the water comes into contact with.
This project focuses upon the migration of radionuclides through these fracture networks where diffusion into the rock matrix and sorption processes are important retardation mechanisms. The main thrust of the project is the continued development of the Channel Network Model for radionuclide migration incorporated in the CHAN3D simulation code as well as to develop improved methods for estimating the flow-wetted surface.
Responsible researchers
Assoc. Prof. Longcheng Liu
Professor Luis R Moreno