
The LASGIT (Large Scale Gas Injection Test) project is a full-scale test of gas transport in a bentonite buffer surrounding a full-scale nuclear waste canister at the Äspö Hard Rock Laboratory in Sweden. The purpose of the LASGIT experiment is to improve the understanding of full-scale gas migration through the bentonite buffer under repository conditions and to validate different modelling approaches which may be used in future performance assessments. The current gas-transport modelling approach uses TOUGH2, a multi-phase flow and transport code, with modifications to the code to simulate potential gas transport mechanisms, mainly micro- and macro- fracturing of the bentonite, by allowing pressure-induced changes to the bentonite permeability and capillary pressure.